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The research was carried out as part of the preparation "Water Resources" section of the 4th National Communication of the Kyrgyz Republic to the UNFCCC. The article presents extensive information on the current state and changes over a long period of observations of water resources, climate and glaciation in Kyrgyzstan (Syr-Darya and Amu-Darya river basins). The representative rivers were selected as the main objects, which are transboundary between Kyrgyzstan, Uzbekistan, Kazakhstan and Tajikistan. The study aims to assess the inter-annual and intra-annual dynamics of the flow of the rivers for the period from 2020 to 2080, based on the climate projections CMIP5 (RCP4.5 and RCP8.5) and CMIP6 (SSP2-4.5 and SSP5-8.5) (IPCC WG II Report, 2022). The hydrological modeling method in the HBV light and HBV EHT models and the inertial mean annual flow change method were used to estimate changes in water resources. On the rivers of the northern part of the Fergana Valley, the average annual runoff is expected to increase by 1-19%, in the Amudarya river basin (Kyzyl-Suu river) - by 27-64% of the values for 2006-2019. In the Naryn river, water discharge for this period will remain within the current values for 2006-2019. The method of inertial change in the average annual runoff showed an increase in runoff for 2030 and 2040 for all the studied catchment areas by 6-19% of the current values for 2006-2020T. he results of the study are intended for decision-makers on the rational use and long-term planning of water resources under climate change. [ABSTRACT FROM AUTHOR]

Motivated by the ongoing debates about the relative contribution of specific North African dust sources to the transatlantic dust transport to the Amazon Basin, the current study integrates a suite of satellite observations into a novel trajectory analysis framework to investigate dust transport from the leading two North African dust sources, namely, the Bodélé depression and El Djouf. In particular, this approach provides observation‐constrained quantification of the dust's dry and wet deposition along its transport pathways and is validated against multiple satellite observations. The current large ensemble trajectory simulations identify favorable transport pathways from the El Djouf across the Atlantic Ocean with respect to seasonal rain belts. The limited potential for long‐range transport of dust from the Bodélé depression is attributed to the currently identified extensive near‐source dust removal primarily by dry and wet deposition during boreal winter and summer, respectively. Plain Language Summary: North African deserts have been reported to export ~200 million tons of dust per year to the tropical Atlantic Ocean, degrading air quality over the Caribbean Islands in boreal summer and supplying nutrients to fertilize the Amazon Rainforest in boreal winter and spring through transatlantic dust transport. It has been assumed that the Bodélé depression is the main contributor to this transatlantic dust transport and Amazonian dust fertilization in boreal winter. However, these claims have not been supported by geochemical analysis. Here, we integrate a suite of satellite observations into a novel trajectory analysis framework to investigate dust transport from the leading two North African dust sources, namely, the Bodélé depression and El Djouf, and provide the first ever observation‐constrained quantification of the dust's dry and wet deposition along its transport pathways. The approach yields the novel observational finding that the El Djouf is the preferred source of intercontinental transport across the Atlantic Ocean rather than the Bodélé depression, bridging the geochemical impact of North African minerals on the Amazon Basin to the specific dust origin. Key Points: The current trajectory simulations quantify observation‐derived dust deposition and capture the observed three‐dimensional dust distributionEl Djouf is the preferred source of the transatlantic dust transport, due to favorable transport pathways with respect to seasonal rain beltsExtensive near‐source dust deposition supports the observed limited potential for long‐range transport of dust from the Bodélé depression [ABSTRACT FROM AUTHOR]

• Developed an improved dust soiling model and validated it against published data. • Satellite-derived input PM data performed slightly better than reanalysis only. • Dry-season soiling losses can be more than 50% near the Sahara Desert. • In Bamako, Mali, 21 cleanings per year are required to keep soiling losses below 1% • Total PV panel cleaning costs in SSA could rise to $1Bn (USD) annually by 2030. West Africa's proximity to the Sahara Desert can cause photovoltaic (PV) systems to experience significant power generation reductions when particulates settle onto solar panel surfaces in a phenomenon known as soiling. Previous studies have created models to estimate PV soiling globally, but these models have several limitations in the region due to the accuracy of the input particular matter (PM) concentration values, the accuracy of methods for computing power loss, and the regional use of decentralized solar systems. Here we develop and apply a methodology for the development of a soiling estimation model based on the Coello framework, and evaluate it when using input PM concentration values from both a reanalysis dataset (MERRA-2) and a dataset derived from satellite-observations (WUSTL). This model reduces error in soiling-related power loss estimates by approximately 50% when compared to the unadjusted Coello approach. Using this model, we find soiling losses can exceed 50% in the most greatly affected locations during the Harmattan season and these power losses can vary considerably each year (between 26 and 53% in Niamey, Niger). To support PV system design, we develop a function that relates maximum soiling losses to annual cleaning frequencies in major cities. Finally, we find if decentralized solar is used to meet electricity access goals as projected, PV cleaning costs could sum up to $1Bn (USD) annually in sub-Saharan Africa by 2030. [ABSTRACT FROM AUTHOR]

Abstract: Motivated by limitations in current satellite‐based dust source identification techniques, this study examines dust emissions and concentrations over North Africa and the Middle East during 2000–2016 by analyzing stereo and optical products from the Multiangle Imaging SpectroRadiometer instrument on the National Aeronautics and Space Administration polar‐orbiting Terra satellite. Based on the occurrence of fast‐moving, near‐surface dust plumes from the Multiangle Imaging SpectroRadiometer cloud motion vector product, dust sources in the study region are identified in geographical depressions, including the Bodélé Depression, which represents the leading source. The West African El Djouf desert generates substantial dust emissions, which are typically underestimated by aerosol loading‐based dust source identifications. In response to local vegetation cover anomalies, dust emissions and concentrations increased at 15% year−1 over the Middle East and decreased at 12% year−1over the central Sahel during 2001–2013 but partly recovered toward their climatological means afterward. [ABSTRACT FROM AUTHOR]

There is significant public health interest in gaining a better understanding of the health effects associated with particulate matter (PM) of differing sizes and compositions. Unfortunately the PM monitoring data needed for such studies are limited. Satellite observations of aerosol optical depth (AOD) have been used to overcome this limitation, but existing techniques using AOD to estimate surface concentrations of PM have limited ability to differentiate particle size and type, and the spatial resolution is often too coarse to evaluate PM variability on local scales. Fortunately there has been a significant breakthrough in aerosol product from the Multi-angle Imaging SpectroRadiometer (MISR) instrument onboard the NASA Terra satellite. Recent computational advances have made it possible to derive a “local mode” MISR aerosol product at a spatial resolution of 4.4 km that maintains the quality of the 17.6 km resolution Version 22 operational aerosol product. MISR is uniquely capable of providing total AOD as well as AOD fractionated by size (small, medium, and large), enabling estimation of size-resolved surface PM concentrations. Total and size-fractionated AOD from the MISR 4.4 km aerosol product were used to develop spatio-temporal models to estimate surface concentrations of PM 2.5 , PM 10 , and PM 2.5 chemical species over Southern California. We found, and confirmed by leave-one-site-out cross validation, that PM 2.5 was best estimated with a spatio-temporal model of AOD small + medium that also included adjustment for relative humidity and wind speed (R 2 = 0.67, CV R 2 = 0.51), while PM 10 was best estimated from AOD large with adjustment for dew point and wind speed (R 2 = 0.76, CV R 2 = 0.44). Total AOD was most strongly associated with PM 2.5 components SO 4 2 − (R 2 = 0.74, CV R 2 = 0.69) and NO 3 − (R 2 = 0.72, CV R 2 = 0.39). The best fitting models were applied to all available MISR aerosol retrievals over the region, generating surfaces of estimated size-resolved PM concentrations that will be a great asset to the environmental science and public health communities. [ABSTRACT FROM AUTHOR]

We investigate to what extent multi-angle polarimetric measurements are sensitive to vertical mixing/layering of absorbing aerosols, adopting calibration uncertainty of 1.5% in intensity and 0.5% in the degree of linear polarization of Multiangle Spectro-Polarimetric Imager (MSPI). Employing both deterministic and Monte Carlo radiative transfer codes with polarization, we conduct modeling experiments to determine how the measured Stokes vector elements are affected at UV and short visible wavelengths by the vertical distribution, mixing and layering of smoke and dust aerosols for variety of microphysical parameters. We find that multi-angular polarimetry holds the potential to infer dust-layer heights and thicknesses at blue visible channel due to its lesser sensitivity to changes in dust coarse mode optical properties, but higher sensitivity to the dust vertical profiles. Our studies quantify requirements for obtaining simultaneous information on aerosol layer height and absorption under MSPI measurement uncertainties. [ABSTRACT FROM AUTHOR]

Abstract: The impact of tropospheric aerosols on climate can vary greatly based upon relatively small variations in aerosol properties, such as composition, shape and size distributions, as well as vertical layering. Polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol radiative forcing on climate. The goal of this study is to introduce a formal approach to assessing the sensitivity of both intensity and polarization signals to absorbing aerosol layering, explicitly accounting for instrument measurement uncertainties. If ignored, sensitivity to aerosol height can introduce biases in aerosol property retrievals at short (ultraviolet or blue) wavelengths; if properly exploited, it may enable the extraction of some basic information on aerosol profiles. Employing a vector successive-orders-of-scattering (SOS) radiative transfer code, we conducted modeling experiments to determine how the measured Stokes vector elements are affected at 446nm (blue band) by the vertical distribution, mixing and layering of smoke and dust aerosols under the assumption of a simple Lambertian surface and predefined aerosol microphysical properties. We find that smoke and dust vertical layering, if ignored, can introduce biases in radiometric and polarimetric aerosol property retrievals for aerosol optical depth (AOD) above 0.3 (polarimetric) and AOD above 0.5 (radiometric), and should, therefore, be accounted for in retrievals at high aerosol loadings. [Copyright &y& Elsevier]

An understanding of the effect of aerosols on biologically-and photochemically-active UV radiation reaching the Earth''s surface is important for many ongoing climate, biophysical, and air pollution studies. In particular, estimates of the UV characteristics of the most common Australian aerosols will be valuable inputs to UV Index forecasts, air quality studies, and assessments of the impact of regional environmental changes. By analyzing climatological distributions of Australian aerosols we have identified sites where co-located ground-based UV-B and ozone measurements were available during episodes of relatively high aerosol activity. Since at least June 2003, surface UV global irradiance spectra (285–450 nm) have been measured routinely at Darwin and Alice Springs in Australia by the Australian Bureau of Meteorology (BoM). Using co-located sunphotometer measurements at Darwin and Alice Springs, we identified several episodes of relatively high aerosol activity. Aerosol air mass types were analyzed from sunphotometer-derived angstrom parameter, MODIS fire maps and MISR aerosol property retrievals. To assess aerosol effects we compared the measured UV irradiances for aerosol-loaded and clear-sky conditions with each other and with irradiances simulated using the libRadtran radiative transfer model for aerosol-free conditions. We found that for otherwise similar atmospheric conditions, smoke aerosols over Darwin reduced the surface UV irradiance by as much as 40–50% at 290–300 nm and 20–25% at 320–400 nm near active fires (aerosol optical depth, AOD, at 500 nm ∼ 0. 6). Downwind of fires, the smoke aerosols over Darwin reduced the surface irradiance by 15–25% at 290–300 nm and ∼ 10% at 320–350 nm (AOD at 500 nm ∼ 0. 2). The effect of smoke increased with decrease of wavelength and is strongest in the UV-B. The aerosol attenuation factors calculated for the selected cases suggest smoke over Darwin has an effect on surface 340–380 nm irradiances that is comparable to that produced by smoke over Sub-Saharan Africa. Dust activity was very low at Alice Springs during 2004, therefore we were not able to identify strong dust events to fully assess the UV effect of dust. For the cases studied, smoke aerosols seem to produce a stronger reduction in surface UV irradiances than dust aerosols. [Copyright &y& Elsevier]

Traditionally, aerosol retrieval algorithms are customized to specific instruments because of the diverse nature of remote sensing hardware architectures and data formats. This diversity can hinder the utilization of lower-level data products. Furthermore, a generalized aerosol retrieval approach has the potential to allow simultaneous use of observations from multiple platforms within a single retrieval framework. In this work, a comprehensive set of solutions for integrating open-source aerosol retrieval software and publicly available multiangle spectropolarimetric data products is presented as a complementary software program (CSP). This CSP is adaptable to observations obtained from various instruments, including the Airborne Multiangle Spectropolarimetric Imager (AirMSPI) and the upcoming Multiangle Imager for Aerosols (MAIA) (Diner et al., 2013); (Maia, 2022). Established methods for reconciling coordinate systems, curating data, and structuring data for input to the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) open-source software are addressed by the CSP (Grasp-open, 2023).The CSP provides the functionality to compute multiple GRASP aerosol retrievals from the same polarimetric observations by varying the user-defined coordinate system selection. Each coordinate system is defined by a unique reference plane, which rotates the reported polarization orientation but does not alter the information content. Therefore retrieving aerosol values from different coordinate systems is suggested as a tool for: (1) verifying the coordinate systems of the instrument and algorithm have been properly reconciled and (2) quantifying numerical variations in the retrieval's optimization algorithm. The CSP is demonstrated using AirMSPI data from the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign (Diner et al., 2013); (Warneke, 2019). Aerosol retrievals performed with the meridian versus the scattering reference plane differed up to 0.068 in aerosol optical depth and 0.015 in single scattering albedo. These variations in smoke properties from multiangle spectropolarimetric observations quantify uncertainty which is applicable for cross-validation instrument comparisons and studies of different retrieval algorithms. • Polarimetric Geometry Reconciliation Validation Using Two Reference Planes. • Merging Multiangle Polarimetric Data and a Generalized Radiative Transfer Algorithm. • GRASP Aerosol Retrievals of AirMSPI FIREX-AQ Data. • Python Code to Prepare Data for GRASP Input. [ABSTRACT FROM AUTHOR]

Dust from North Africa has been reported to affect the air quality over Caribbean Islands and southeastern United State, as well as supplying nutrients to fertilize the Amazon forest. However, the relative contribution from North Africa dust sources, namely the Bodélé depression and West African deserts, has been debated among different observational and modeling studies. In the current study, dust transport from the Bodélé depression and West African desert are investigated using an observationally constraint, advanced trajectory model that quantifies both dry and wet deposition along trajectory, based on observations of precipitation amount and cloud properties, and is initiated by stereo observations of dust plume height from the Multiangle Imaging SpectroRadiometer (MISR) instrument. Our advanced trajectory model provides an encouraging tool for investigating dust transport, given its capability at successful capturing the observed horizontal and vertical structures of dust transport across the Atlantic.Based on the advanced trajectory modeling, we found the West African deserts contributes substantially more dust than the Bodélé depression to the trans-Atlantic transport in both boreal winter and summer. The relatively contribution from the two North African dust sources are mainly due to differentiated dust transport pathways. For dust particles emitted from both dust sources, wet deposition, primarily driven by substantial rainfall associated with Intertropical Convergence Zone over ocean and intertropical rainbelt over land, overwhelms dry deposition and largely reduces the amount of dust transport to south America in boreal winter and Central and North Americas in boreal summer. According to the precise observation of dust plume height and motion by MISR, substantial removal and suppression of dust plumes occur near the Bodélé depression, supporting the limited potential for long-range transport of dust from the Bodélé depression revealed by the current advanced trajectory modeling. [ABSTRACT FROM AUTHOR]

Snow accumulation in mountains plays an important role in seasonal discharge in summer month in many parts of the world. Winter precipitation falling as snow in the cold period is stored in the mountains and released as meltwater during a warm period when demand is high, providing water to millions of people in downstream countries. This is of particular importance in semi-arid regions, where precipitation during the warm season is minimal. Therefore, it is important to monitor snow accumulation in the mountains for seasonal water availability assessments. However, direct observations in the mountains are usually rare due to limited accessibility and extreme weather conditions. Nowadays, remote sensing snow cover products deliver observations of the snow state with moderate spatial and high temporal resolution, which can be applied to monitor snow cover in mesoscale mountainous catchments. In this study, we present a methodology to forecast seasonal and monthly water availability in mountainous areas. We use daily MODIS snow cover time series with 500 m spatial resolution to derive a snow cover index (SCI), a new index representing snow accumulation in the mountains representing the evolution of the snow accumulation. The SCI was then applied to forecast seasonal and monthly water availability based on linear models. The SCI was derived for a whole basin to forecast water availability in the vegetation period, whereas the elevation dependent SCI was applied to forecast water availability for upcoming months. The elevation dependent SCI was derived by disintegrating the snow cover area into defined elevation bands. This leads to the temporal assessment of snow cover state at different elevation zones contributing to total river discharge at different time scales. In a pilot study, the forecasting methodology was applied for 12 river basins in Central Asia. The results show that using SCI, on average 0.67 of the variance can be explained in forecasting seasonal water availability. As for the monthly forecast, the maximum explained variance of 0.70-0.80 was obtained for June, July, August and September months, indicating a strong dependence of water availability in these months on snow storage in the mountains, particularly in high elevation zones. For the months March, April, and May, the obtained explained variance is in the order of 0.6 indicating that not only snow contributes to river discharge in these months but also other components such as rain and groundwater. Using the presented methodology, linear forecast models based on remote sensing snow cover information can be derived. The forecasting methodology considering remote sensing snow cover data is of high applied importance in Central Asia and is currently being implemented into the forecasting workflows of local hydrometeorological services. [ABSTRACT FROM AUTHOR]

This study investigates the attribution of climate change to trends in river discharge during six decades from 1955 until 2014 in 12 selected river catchments across six Central Asian countries located upstream of the main rivers. For this purpose, the semi-distributed eco-hydrological model SWIM (Soil and Water Integrated Model) was firstly calibrated and validated for all study catchments. Attributing climate change to streamflow simulation trends was forced by factual (reanalysis) and counterfactual climate data (assuming the absence of anthropogenic influence) proposed in the framework of the ISIMIP (Inter-Sectoral Impact Model Intercomparison Project) or ESM without anthropogenic forcing that were firstly tested and then compared. The trend analysis was performed for three variables: mean annual discharge and high flow (Q5) and low flow (Q95) indices. The results show that trends in the annual and seasonal discharge could be attributed to climate change for some of the studied catchments. In the three northern catchments (Derkul, Shagan, and Tobol), there are positive trends, and in two catchments (Sarysu and Kafirnigan), there are negative streamflow trends under the factual climate, which could be attributed to climate change. Also, our analysis shows that the average level of discharge in Murghab has increased during the historical study period due to climate change, despite the overall decreasing trend during this period. In addition, the study reveals a clear signal of shifting spring streamflow peaks in all catchments across the study area. [ABSTRACT FROM AUTHOR]

Recent use of satellite observations of aerosol optical depth (AOD) to characterize surface concentrations of particulate matter (PM) air pollution has proven extremely valuable in estimating exposures for health effects studies. While the spatial resolutions of satellite data provide far better coverage than existing fixed site surface monitoring stations, they are not able to capture atmospheric processes such as dilution of primary pollutants that vary at small spatial scales. As a result, small-scale variability due to highly localized sources such as traffic may be poorly represented, which in turn may lead to exposure measurement error in epidemiological analyses. Using a fixed spatial grid representing 4.4 km Multiangle Imaging SpectroRadiometer (MISR) aerosol observations, we examined the spatial variability in fine and coarse mode PM (PM2.5 and PM2.5–10 respectively) measured at ground monitors from a unique spatially-dense sampling campaign in Southern California. We found that while the variance in measured PM2.5 differed seasonally (warm 6.82 μg2/m6 and cool 24.5 μg2/m6) across the study region, the average subgrid (<4.4 km) variance did not (warm 2.03 μg2/m6 and cool 2.43 μg2/m6) and was significantly smaller. On the other hand, ground monitor PM2.5–10 concentrations showed large variance in warm (18.6 μg2/m6) and cool (20.6 μg2/m6) seasons, as well as seasonal differences in subgrid variance (warm 8.90 μg2/m6 and cool 3.28 μg2/m6). Geostatistical analysis of the semivariance as a function of distance indicated that variability in measured PM2.5 and PM2.5–10 concentrations was relatively constant for spatial scales of one to five kilometers, but there was evidence of small-scale (~500 m) variability in PM2.5–10 concentrations in the cool season. The lack of small-scale spatial variability in the warm season was likely due to large photochemical contributions to regional PM2.5, and greater regional contributions to PM2.5–10 from windblown dust. In contrast, in the cool season there tends to be greater localized concentrations from primary traffic sources due to stronger nocturnal inversions and delayed morning winds reducing dilution that contribute to greater spatial heterogeneity. Overall, these results suggest that regional contributions tend to dominate PM2.5, and spatial resolutions of satellite observations including the 4.4 km MISR and 3 km MODIS aerosol products aptly capture relevant spatial variability. Coarse PM2.5–10 can have seasonally dependent localized contributions, leading to small-scale variability below current satellite aerosol product resolutions. [ABSTRACT FROM AUTHOR]

The 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field experiment obtained a diverse set of in situ and remotely sensed measurements before and during a pyrocumulonimbus (pyroCb) event over the Williams Flats fire in Washington State. This unique dataset confirms that pyroCb activity is an efficient vertical smoke transport pathway into the upper troposphere and lower stratosphere (UTLS). The magnitude of smoke plumes observed in the UTLS has increased significantly in recent years, following unprecedented wildfire and pyroCb activity observed worldwide. The FIREX-AQ pyroCb dataset is therefore extremely relevant to a broad community, providing the first measurements of fresh smoke exhaust in the upper troposphere, including from within active pyroCb cloud tops. High-resolution remote sensing reveals that three plume cores linked to localized fire fronts, burning primarily in dense forest fuels, contributed to four total pyroCb "pulses." Rapid changes in fire geometry and spatial extent dramatically influenced the magnitude, behavior, and duration of pyroCb activity. Cloud probe measurements and weather radar identify the presence of large ice particles within the pyroCb and hydrometers below cloud base, indicating precipitation development. The resulting feedbacks suggest that vertical smoke transport efficiency was reduced slightly when compared with intense pyroCb events reaching the lower stratosphere. Physical and optical aerosol property measurements in pyroCb exhaust are compared with previous assumptions. A large suite of aerosol and gas-phase chemistry measurements sets a foundation for future studies aimed at understanding the composition of smoke plumes lifted by pyroconvection into the UTLS and their role in the climate system. [ABSTRACT FROM AUTHOR]

Miscanthus is a perennial wild plant that is vital for the production of paper and roofing, as well as horticulture and the development of new high-yielding crops in temperate climates. Chromosome-level assembly of the ancient tetraploid genome of miscanthus chromosomes is reported to provide resources that can link its chromosomes to related diploid sorghum and complex polyploid sugarcane. Analysis of Miscanthus sinensis and Miscanthus sacchariflorus showed intense mixing and interspecific hybridization and documented the origin of a high-yielding triploid bioenergetic plant, Miscanthus × giganteus. The Miscanthus genome expands comparative genomics functions to better understand the main abilities of Andropogoneae herbs. Miscanthus × giganteus is widely regarded as a promising lignocellulosic biomass crop due to its high-biomass yield, which does not emit toxic compounds into the environment, and ability to grow in depleted lands. The high production cost of lignocellulosic bioethanol limits its commercialization. The main components that inhibit the enzymatic reactions of fermentation and saccharification are lignin in the cell wall and its by-products released during the pre-treatment stage. One approach to overcoming this barrier could be to genetically modify the genes involved in lignin biosynthesis, manipulating the lignin content and composition of miscanthus. [ABSTRACT FROM AUTHOR]

The Indian subcontinent occupies 2.4% of the world land mass and is home to ∼17% of the world population. It is characterized by a wide range of population density (P), significant population growth and high levels of air pollution. The quantification of the effect of urbanization on aerosol optical thickness (AOT) trends was carried out by analysing 8-year (March 2000 to February 2008) Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging SpectroRadiometer (MISR) satellite data. Here we show that over extensive areas with differing population densities, which are significant parts of the Indian subcontinent, (1) the higher the averaged population density the bigger the averaged AOT and (2) the larger the population growth the stronger the increasing trends in AOT. Over the regions with P > 100 persons km−2 (more than 70% of the territory), a population growth of ∼1.5% year−1 was accompanied by increasing AOT trends of over 2% year−1. The presence of the aforementioned AOT trends is evidence of air quality deterioration, in particular in highly populated areas with P > 500 persons km−2. This situation could worsen with the continued growth of the Indian population. [ABSTRACT FROM AUTHOR]

Since early 2000, NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument has been performing remote sensing retrievals of aerosol optical properties from the polar-orbiting Terra spacecraft. A noteworthy aspect of MISR observations over the ocean is that, for much of the Earth, some of the multi-angle views have contributions from solar reflection by the ocean surface (glint, or glitter), while others do not. Aerosol retrieval algorithms often discard these glint-influenced observations because they can overwhelm the signal and are difficult to predict without knowledge of the (wind-speed-driven) ocean surface roughness. However, theoretical studies have shown that multi-angle observations of a location at geometries with and without reflected sun glint can be a rich source of information, sufficient to support simultaneous retrieval of both the aerosol state and the wind speed at the ocean surface. We are in the early stages of creating such an algorithm. In this paper, we describe our assessment of the appropriate level of parameterization for simultaneous aerosol and ocean surface property retrievals using sun glint. For this purpose, we use generalized nonlinear retrieval analysis (GENRA), an information content assessment (ICA) technique employing Bayesian inference, and simulations from the Ahmad–Fraser iterative radiative transfer code. We find that four parameters are suitable: aerosol optical depth (τ), particle size distribution (expressed as the fine mode fraction f of small particles in a bimodal size distribution), surface wind speed (w), and relative humidity (r , to define the aerosol water content and complex refractive index). None of these parameters define ocean optical properties, as we found that the aerosol state could be retrieved with the nine MISR near-infrared views alone, where the ocean body is strongly absorbing in the open ocean. We also found that retrieval capability varies with observation geometry and that as τ increases so does the ability to determine aerosol intensive optical properties (r and f , while it decreases for w). Increases in w decrease the ability to determine the true value of that parameter but have minimal impact on retrieval of aerosol properties. We explored the benefit of excluding the two most extreme MISR view angles for which radiative transfer with the plane-parallel approximation is less certain, but we found no advantage in doing so. Finally, the impact of treating wind speed as a scalar parameter, rather than as a two-parameter directional wind, was tested. While the simpler scalar model does contribute to overall aerosol uncertainty, it is not sufficiently large to justify the addition of another dimension to parameter space. An algorithm designed upon these principles is in development. It will be used to perform an atmospheric correction with MISR for coincident ocean color (OC) observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, also on the NASA Terra spacecraft. Unlike MISR, MODIS is a single-view-angle instrument, but it has a more complete set of spectral channels ideal for determination of optical ocean properties. The atmospheric correction of MODIS OC data can therefore benefit from MISR aerosol retrievals. Furthermore, higher-spatial-resolution data from coincident MISR observations may also improve glint screening. [ABSTRACT FROM AUTHOR]

Primary productivity (PP) has been recently investigated using remote sensing-based models over quite limited geographical areas of the Red Sea. This work sheds light on how phytoplankton and primary production would react to the effects of global warming in the extreme environment of the Red Sea and, hence, illuminates how similar regions may behave in the context of climate variability. study focuses on using satellite observations to conduct an intercomparison of three net primary production (NPP) models—the vertically generalized production model (VGPM), the Eppley-VGPM, and the carbon-based production model (CbPM)—produced over the Red Sea domain for the 1998–2018 time period. A detailed investigation is conducted using multilinear regression analysis, multivariate visualization, and moving averages correlative analysis to uncover the models’ responses to various climate factors. Here, we use the models’ eight-day composite and monthly averages compared with satellite-based variables, including chlorophyll-a (Chla), mixed layer depth (MLD), and sea-surface temperature (SST). Seasonal anomalies of NPP are analyzed against different climate indices, namely, the North Pacific Gyre Oscillation (NPGO), the multivariate ENSO Index (MEI), the Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation (NAO), and the Dipole Mode Index (DMI). In our study, only the CbPM showed significant correlations with NPGO, MEI, and PDO, with disagreements relative to the other two NPP models. This can be attributed to the models’ connection to oceanographic and atmospheric parameters, as well as the trends in the southern Red Sea, thus calling for further validation efforts. [ABSTRACT FROM AUTHOR]

Since early 2000, NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument has been performing remote sensing retrievals of aerosol optical properties from the polar orbiting Terra spacecraft. A noteworthy aspect of MISR observations over the ocean is that, for much of the Earth, some of the multi-angle views have contributions from solar reflection by the ocean surface (glint, or glitter), while others do not. Aerosol retrieval algorithms often discard these glint influenced observations because they can overwhelm the signal and are difficult to predict without knowledge of the (wind speed driven) ocean surface roughness. However, theoretical studies have shown that multi-angle observations of a location at geometries with and without reflected sun glint can be a rich source of information, sufficient to support simultaneous retrieval of both the aerosol state and the wind speed at the ocean surface. We are in the early stages of creating such an algorithm. In this manuscript, we describe our assessment of the appropriate level of parameterization for simultaneous aerosol and ocean surface property retrievals using sun glint. For this purpose, we use Generalized Nonlinear Retrieval Analysis (GENRA), an information content assessment (ICA) technique employing Bayesian inference, and simulations from the Ahmad-Fraser iterative radiative transfer code. We find that four parameters are suitable: aerosol optical depth (τ), particle size distribution (expressed as the fine mode fraction f of small particles in a bimodal size distribution), surface wind speed (w), and relative humidity (r, to define the aerosol water content and complex refractive index). None of these parameters define ocean optical properties, as we found that the aerosol state could be retrieved with the nine MISR near-infrared views alone, where the ocean body is black in the open ocean. We also found that retrieval capability varies with observation geometry, and that as τ increases so does the ability to determine aerosol intensive optical properties (r and f, while it decreases for w). Increases in wind speed decrease the ability to determine the true value of that parameter, but have minimal impact on retrieval of aerosol properties. We explored the benefit of excluding the two most extreme MISR view angles for which radiative transfer with the plane parallel approximation is less certain, but found no advantage in doing so. Finally, the impact of treating wind speed as a scalar parameter, rather than as a two parameter directional wind, was tested. While the simpler scalar model does contribute to overall aerosol uncertainty, it is not sufficiently large to justify the addition of another dimension to parameter space. An algorithm designed upon these principles is in development. It will be used to perform an atmospheric correction with MISR for coincident ocean color (OC) observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, also on the NASA Terra spacecraft. Unlike MISR, MODIS is a single view angle instrument, but it has a more complete set of spectral channels ideal for determination of ocean optical properties. The atmospheric correction of MODIS OC data can therefore benefit from MISR aerosol retrievals. Furthermore, higher spatial resolution data from coincident MISR observations may also improve glint screening. [ABSTRACT FROM AUTHOR]

The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been operational on the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Terra satellite since early 2000, creating an extensive data set of global Earth observations. Here we introduce the latest version of the MISR aerosol products. The level 2 (swath) product, which is reported on a 4.4 km spatial grid, is designated as version 23 (V23) and contains retrieved aerosol optical depth (AOD) and aerosol particle property information derived from MISR's multi-angle observations over both land and water. The changes from the previous version of the algorithm (V22) have significant impacts on the data product and its interpretation. The V23 data set is created from two separate retrieval algorithms that are applied over dark water and land surfaces, respectively. Besides increasing the horizontal resolution to 4.4 km compared with the coarser 17.6 m resolution in V22 and streamlining the format and content, the V23 product has added geolocation information, pixel-level uncertainty estimates, and improved cloud screening. MISR data can be obtained from the NASA Langley Research Center Atmospheric Science Data Center at https://eosweb.larc.nasa.gov/project/misr/misr%5ftable (last access: 11 October 2019). The version number for the V23 level 2 aerosol product is F13_0023. The level 3 (gridded) aerosol product is still reported at 0.5∘×0.5∘ spatial resolution with results aggregated from the higher-resolution level 2 data. The format and content at level 3 have also been updated to reflect the changes made at level 2. The level 3 product associated with the V23 level 2 product version is designated as F15_0032. Both the level 2 and level 3 products are now provided in NetCDF format. [ABSTRACT FROM AUTHOR]

The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been operational on the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Terra satellite since early 2000, creating an extensive data set of global Earth observations. Here we introduce the latest version of the MISR aerosol products. The Level 2 (swath) product, which is reported on a 4.4 km spatial grid, is designated Version 23 (V23) and contains retrieved aerosol optical depth (AOD) and aerosol particle property information derived from MISR's multi-angle observations over both land and water. The changes from the previous version of the algorithm (V22) have significant impacts on the data product and its interpretation. The V23 data set is created from two separate retrieval algorithms that are applied over dark water and land surfaces, respectively. Besides increasing the horizontal resolution to 4.4 km compared with the coarser 17.6 m resolution in V22, and streamlining the format and content, the V23 product has added geolocation information, pixel-level uncertainty estimates, and improved cloud screening. MISR data can be obtained from the NASA Langley Research Center Atmospheric Science Data Center at https://eosweb.larc.nasa.gov/project/misr/misr_table. The version number for the V23 Level 2 aerosol product is F13_0023. The Level 3 (gridded) aerosol product is still reported at 0.5° x 0.5° spatial resolution with results aggregated from the higher-resolution Level 2 data. The format and content at Level 3 have also been updated to reflect the changes made at Level 2. The Level 3 product associated with the V23 Level 2 product version is designated F15_0032. Both the Level 2 and Level 3 products are now provided in NetCDF format. [ABSTRACT FROM AUTHOR]

Exposure to fine particulate matter (PM 2.5) is the leading environmental risk factor for mortality globally. Satellite-derived estimates of surface PM 2.5 developed from a combination of satellites, simulations, and ground monitor data are relied upon for health impact studies. The ability to develop satellite-derived PM 2.5 estimates requires the continued availability of aerosol optical depth (AOD) sources. This work examines the impact of the addition or loss of satellite AOD data sources on global PM 2.5 estimation and the impact of continuing the long-term record with AOD from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi-National Polar orbiting Partnership (S-NPP) satellite after the loss of the MODIS (MODerate resolution Imaging Spectroradiometer) and MISR (Multi-angle Imaging Spectroradiometer) instruments on board the Terra and Aqua satellites. We find that the addition of VIIRS S-NPP AOD products to geophysical PM 2.5 estimates from satellites and simulations causes regional differences that correspond to differences in the VIIRS and MODIS Deep Blue AOD algorithms and sampling. Changes in long-term trends and timeseries due to the addition or loss of AOD data sources are generally within their uncertainties. Statistical fusion with ground monitor data partially corrects for changes due to sampling differences when introducing the VIIRS AOD products, but uncertainty remains over desert regions where ground monitor coverage is sparse. This work provides promise for the sustained development of global satellite-derived PM 2.5 estimates, despite discontinuities in instruments and retrieval methods. • Impact of changing satellite AOD sources on global PM 2.5 estimation is examined. • Algorithm inconsistencies and sampling cause regional differences in PM 2.5. • Changes in trends due to the discontinuity of AOD sources are within uncertainties. • Statistical fusion with ground monitors partially corrects for sampling impacts. • Global sat-derived PM 2.5 record is sustained despite AOD source discontinuities. [ABSTRACT FROM AUTHOR]

Background Juvenile systemic lupus erythematosus (JSLE) is a severe life-threatening disease. The place of rituximab in JSLE management is still undefined. The early biologic intervention might improve disease's outcomes. Aim of study To assess the advantages of early rituximab administration compared with late. Material and methods In the retrospective cohort study the information about 36 JSLE patients, whom rituximab biosimilar BCD020 was initiated were included. All patients were divided in two groups: early start of rituximab (less than six months from onset) and late start (more than one year). We compared initial disease characteristics at onset, on the baseline (BL)—start of rituximab and end of the study—(EOS) - 12 months, and treatment characteristics. Results The time gap between early and late rituximab administration was 19 months. There were no differences in disease profile at onset, except higher SLEDAI and MAS frequency in early rituximab group. Baseline differences were: lower C3, C4, higher SLEDAI and oral daily corticosteroids dosage. At the end of the study, patient whom rituximab was prescribed early had more impressive changes in SLEDAI, e.g. 100% of patients decreased SLEDAI, compared with 79% in late rituximab group. The detailed information about disease activity and treatment outcomes in both groups are in the table. There were no differences in adverse events between groups, except more impressive signs of corticosteroid toxicity in group of late rituximab administration. Conclusion Early administration of rituximab biosimilar made it possible to control the JSLE activity faster and reduce the dose of corticosteroids effectively. There were no differences in adverse events, except signs of corticosteroid toxicity in group of late rituximab initiation. This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation (Agreement No. 075–15-2022–301). Ethics The study was approved by the Ethical Committee of the Saint-Petersburg State Pediatric Medical University (Protocol No1/3 from 11/Jan/2021). There were no violations of patient's rights according to the Declaration of Helsinki. OA03 Table 1. Parameter.  Early start of rituximab (n = 16).  Late start of rituximab (n = 19).  P -value.  Time before rituximab, months  3 (2; 6)  22 (14; 36)  0.00001  SLEDAI, BL, points  22 (15; 26)  10 (6; 16)  0.003  SLEDAI, EOS, points  2 (0; 4)  2 (0; 6)  1.0  SLEDAI changes from BL, points  -18 (-13; -24)  -6 (-14 -14)  0.0006  Patients, improved SLEDAI, %  16 (100)  15 (79)  0.05  SLEDAI changes from BL, %  85 (81; 100)  64 (14; 100)  0.099  Daily corticosteroids, BL, mg/kg  1.0 (0.6; 0.1)  0.3 (0.2; 0.8)  0.027  Daily corticosteroids, EOS, mg/kg  0.1 (0.08; 0.16)  0.1 (0.06; 0.2)  0.842  Median daily corticosteroids change from BL, %  85 (60; 88)  68 (33; 90)  0.436  Improvement in SLEDAI from BL        SLEDAI30  16 (100)  14 (74)  0.027  SLEDAI50  16 (100)  13 (68)  0.014  SLEDAI70  15 (94)  9 (47)  0.004  SLEDAI 90  7 (44)  7 (37)  0.678  SLEDAI100  5 (31)  6 (32)  0.984  Parameter.  Early start of rituximab (n = 16).  Late start of rituximab (n = 19).  P -value.  Time before rituximab, months  3 (2; 6)  22 (14; 36)  0.00001  SLEDAI, BL, points  22 (15; 26)  10 (6; 16)  0.003  SLEDAI, EOS, points  2 (0; 4)  2 (0; 6)  1.0  SLEDAI changes from BL, points  -18 (-13; -24)  -6 (-14 -14)  0.0006  Patients, improved SLEDAI, %  16 (100)  15 (79)  0.05  SLEDAI changes from BL, %  85 (81; 100)  64 (14; 100)  0.099  Daily corticosteroids, BL, mg/kg  1.0 (0.6; 0.1)  0.3 (0.2; 0.8)  0.027  Daily corticosteroids, EOS, mg/kg  0.1 (0.08; 0.16)  0.1 (0.06; 0.2)  0.842  Median daily corticosteroids change from BL, %  85 (60; 88)  68 (33; 90)  0.436  Improvement in SLEDAI from BL        SLEDAI30  16 (100)  14 (74)  0.027  SLEDAI50  16 (100)  13 (68)  0.014  SLEDAI70  15 (94)  9 (47)  0.004  SLEDAI 90  7 (44)  7 (37)  0.678  SLEDAI100  5 (31)  6 (32)  0.984  Open in new tab OA03 Table 1. Parameter.  Early start of rituximab (n = 16).  Late start of rituximab (n = 19).  P -value.  Time before rituximab, months  3 (2; 6)  22 (14; 36)  0.00001  SLEDAI, BL, points  22 (15; 26)  10 (6; 16)  0.003  SLEDAI, EOS, points  2 (0; 4)  2 (0; 6)  1.0  SLEDAI changes from BL, points  -18 (-13; -24)  -6 (-14 -14)  0.0006  Patients, improved SLEDAI, %  16 (100)  15 (79)  0.05  SLEDAI changes from BL, %  85 (81; 100)  64 (14; 100)  0.099  Daily corticosteroids, BL, mg/kg  1.0 (0.6; 0.1)  0.3 (0.2; 0.8)  0.027  Daily corticosteroids, EOS, mg/kg  0.1 (0.08; 0.16)  0.1 (0.06; 0.2)  0.842  Median daily corticosteroids change from BL, %  85 (60; 88)  68 (33; 90)  0.436  Improvement in SLEDAI from BL        SLEDAI30  16 (100)  14 (74)  0.027  SLEDAI50  16 (100)  13 (68)  0.014  SLEDAI70  15 (94)  9 (47)  0.004  SLEDAI 90  7 (44)  7 (37)  0.678  SLEDAI100  5 (31)  6 (32)  0.984  Parameter.  Early start of rituximab (n = 16).  Late start of rituximab (n = 19).  P -value.  Time before rituximab, months  3 (2; 6)  22 (14; 36)  0.00001  SLEDAI, BL, points  22 (15; 26)  10 (6; 16)  0.003  SLEDAI, EOS, points  2 (0; 4)  2 (0; 6)  1.0  SLEDAI changes from BL, points  -18 (-13; -24)  -6 (-14 -14)  0.0006  Patients, improved SLEDAI, %  16 (100)  15 (79)  0.05  SLEDAI changes from BL, %  85 (81; 100)  64 (14; 100)  0.099  Daily corticosteroids, BL, mg/kg  1.0 (0.6; 0.1)  0.3 (0.2; 0.8)  0.027  Daily corticosteroids, EOS, mg/kg  0.1 (0.08; 0.16)  0.1 (0.06; 0.2)  0.842  Median daily corticosteroids change from BL, %  85 (60; 88)  68 (33; 90)  0.436  Improvement in SLEDAI from BL        SLEDAI30  16 (100)  14 (74)  0.027  SLEDAI50  16 (100)  13 (68)  0.014  SLEDAI70  15 (94)  9 (47)  0.004  SLEDAI 90  7 (44)  7 (37)  0.678  SLEDAI100  5 (31)  6 (32)  0.984  Open in new tab [ABSTRACT FROM AUTHOR]

This study used the nearly continuous 17-year observation record from the Multi- angle Imaging SpectroRadiometer (MISR) instrument on the National Aeronautics and Space Administration (NASA) Terra Earth Observing System satellite to determine which temporal subsets are long enough to define statistically stable speciated aerosol optical depth (AOD) climatologies (i.e., AOD by particle types) for purposes of climate model evaluation. A random subsampling of seasonally averaged total and speciated AOD retrievals was performed to quantitatively assess the statistical stability in the climatology, represented by the minimum record length required for the standard deviation of the subsampled mean AODs to be less than a certain threshold. Our results indicate that the multi-year mean speciated AOD from MISR is stable on a global scale; however, there is substantial regional variability in the assessed stability. This implies that in some regions, even 17 years may not provide a long enough sample to define regional mean total and speciated AOD climatologies. We further investigated the agreement between the statistical stability of total AOD retrievals from MISR and the Moderate Resolution Imaging Spectroradiometer (MODIS), also on the NASA Terra satellite. The difference in the minimum record lengths between MISR and MODIS climatologies of total AOD is less than three years for most of the globe, with the exception of certain regions. Finally, we compared the seasonal cycles in the MISR total and speciated AODs with those simulated by three global chemistry transport models in the regions of climatologically stable speciated AODs. We found that only one model reproduced the observed seasonal cycles of the total and non-absorbing AODs over East China, but the seasonal cycles in total and dust AODs in all models are similar to those from MISR in Western Africa. This work provides a new method for considering the statistical stability of satellite-derived climatologies and illustrates the value of MISR's speciated AOD data record for evaluating aerosols in global models. [ABSTRACT FROM AUTHOR]

Ulaanbaatar (UB), the capital city of Mongolia, has extremely poor wintertime air quality with fine particulate matter concentrations frequently exceeding 500 μg/m3, over 20 times the daily maximum guideline set by the World Health Organization. Intensive use of sulfur-rich coal for heating and cooking coupled with an atmospheric inversion amplified by the mid-continental Siberian anticyclone drive these high levels of air pollution. Ground-based air quality monitoring in Mongolia is sparse, making use of satellite observations of aerosol optical depth (AOD) instrumental for characterizing air pollution in the region. We harnessed data from the Multi-angle Imaging SpectroRadiometer (MISR) Version 23 (V23) aerosol product, which provides total column AOD and component-particle optical properties for 74 different aerosol mixtures at 4.4 km spatial resolution globally. To test the performance of the V23 product over Mongolia, we compared values of MISR AOD with spatially and temporally matched AOD from the Dalanzadgad AERONET site and find good agreement (correlation r = 0.845, and root-mean-square deviation RMSD = 0.071). Over UB, exploratory principal component analysis indicates that the 74 MISR AOD mixture profiles consisted primarily of small, spherical, non-absorbing aerosols in the wintertime, and contributions from medium and large dust particles in the summertime. Comparing several machine learning methods for relating the 74 MISR mixtures to ground-level pollutants, including particulate matter with aerodynamic diameters smaller than 2.5 μm ( PM 2.5 ) and 10 μm ( PM 10 ), as well as sulfur dioxide ( SO 2 ), a proxy for sulfate particles, we find that Support Vector Machine regression consistently has the highest predictive performance with median test R 2 for PM 2.5 , PM 10 , and SO 2 equal to 0.461, 0.063, and 0.508, respectively. These results indicate that the high-dimensional MISR AOD mixture set can provide reliable predictions of air pollution and can distinguish dominant particle types in the UB region. [ABSTRACT FROM AUTHOR]

Highlights • The proposed isotope-hydrological integrated modeling approach improved the model performance in the evaluation period. • Involving water isotopic composition for model calibration reduced the model parameter uncertainty. • The isotope-hydrological integrated modeling approach quantified the contributions of runoff components comparably to a tracer-based mixing approach. Abstract Water stable isotope signatures can provide valuable insights into the catchment internal runoff processes. However, the ability of the water isotope data to constrain the internal apportionments of runoff components in hydrological models for glacierized basins is not well understood. This study developed an approach to simultaneously model the water stable isotopic compositions and runoff processes in a glacierized basin in Central Asia. The fractionation and mixing processes of water stable isotopes in and from the various water sources were integrated into a glacio-hydrological model. The model parameters were calibrated on discharge, snow cover and glacier mass balance data, and additionally isotopic composition of streamflow. We investigated the value of water isotopic compositions for the calibration of model parameters, in comparison to calibration methods without using such measurements. Results indicate that: (1) The proposed isotope-hydrological integrated modeling approach was able to reproduce the isotopic composition of streamflow, and improved the model performance in the evaluation period; (2) Involving water isotopic composition for model calibration reduced the model parameter uncertainty, and helped to reduce the uncertainty in the quantification of runoff components; (3) The isotope-hydrological integrated modeling approach quantified the contributions of runoff components comparably to a three-component tracer-based end-member mixing analysis method for summer peak flows, and required less water tracer data. Our findings demonstrate the value of water isotopic compositions to improve the quantification of runoff components using hydrological models in glacierized basins. [ABSTRACT FROM AUTHOR]

Fire is a widespread Earth system process with important carbon and climate feedbacks. Multispectral remote sensing has enabled mapping of global spatiotemporal patterns of fire and fire effects, which has significantly improved our understanding of interactions between ecosystems, climate, humans and fire. With several upcoming spaceborne hyperspectral missions like the Environmental Mapping And Analysis Program (EnMAP), the Hyperspectral Infrared Imager (HyspIRI) and the Precursore Iperspettrale Della Missione Applicativa (PRISMA), we provide a review of the state-of-the-art and perspectives of hyperspectral remote sensing of fire. Hyperspectral remote sensing leverages information in many (often more than 100) narrow (smaller than 20 nm) spectrally contiguous bands, in contrast to multispectral remote sensing of few (up to 15) non-contiguous wider (greater than 20 nm) bands. To date, hyperspectral fire applications have primarily used airborne data in the visible to short-wave infrared region (VSWIR, 0.4 to 2.5 μm). This has resulted in detailed and accurate discrimination and quantification of fuel types and condition, fire temperatures and emissions, fire severity and vegetation recovery. Many of these applications use processing techniques that take advantage of the high spectral resolution and dimensionality such as advanced spectral mixture analysis. So far, hyperspectral VSWIR fire applications are based on a limited number of airborne acquisitions, yet techniques will approach maturity for larger scale application when spaceborne imagery becomes available. Recent innovations in airborne hyperspectral thermal (8 to 12 μm) remote sensing show potential to improve retrievals of temperature and emissions from active fires, yet these applications need more investigation over more fires to verify consistency over space and time, and overcome sensor saturation issues. Furthermore, hyperspectral information and structural data from, for example, light detection and ranging (LiDAR) sensors are highly complementary. Their combined use has demonstrated advantages for fuel mapping, yet its potential for post-fire severity and combustion retrievals remains largely unexplored. [ABSTRACT FROM AUTHOR]

Research efforts to better characterize the differential toxicity of PM 2.5 (particles with aerodynamic diameters less than or equal to 2.5 μm) speciation are often hindered by the sparse or non-existent coverage of ground monitors. The Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite is one of few satellite aerosol sensors providing information of aerosol shape, size and extinction globally for a long and continuous period that can be used to estimate PM 2.5 speciation concentrations since year 2000. Currently, MISR only provides a 17.6 km product for its entire mission with global coverage every 9 days, a bit too coarse for air pollution health effects research and to capture local spatial variability of PM 2.5 speciation. In this study, generalized additive models (GAMs) were developed using MISR prototype 4.4 km-resolution aerosol data with meteorological variables and geographical indicators, to predict ground-level concentrations of PM 2.5 sulfate, nitrate, organic carbon (OC) and elemental carbon (EC) in Southern California between 2001 and 2015 at the daily level. The GAMs are able to explain 66%, 62%, 55% and 58% of the daily variability in PM 2.5 sulfate, nitrate, OC and EC concentrations during the whole study period, respectively. Predicted concentrations capture large regional patterns as well as fine gradients of the four PM 2.5 species in urban areas of Los Angeles and other counties, as well as in the Central Valley. This study is the first attempt to use MISR prototype 4.4 km-resolution AOD (aerosol optical depth) components data to predict PM 2.5 sulfate, nitrate, OC and EC concentrations at the sub-regional scale. In spite of its low temporal sampling frequency, our analysis suggests that the MISR 4.4 km fractional AODs provide a promising way to capture the spatial hotspots and long-term temporal trends of PM 2.5 speciation, understand the effectiveness of air quality controls, and allow our estimated PM 2.5 speciation data to be linked with common spatial units such as census tract or zip code in epidemiological studies. This modeling strategy needs to be validated in other regions when more MISR 4.4 km data becoming available in the future. [ABSTRACT FROM AUTHOR]

An anomalously high chlorophyll-a (Chl-a) event (>2 mg/m3) during June 2015 in the South Central Red Sea (17.5° to 22°N, 37° to 42°E) was observed using Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra and Aqua satellite platforms. This differs from the low Chl-a values (<0.5 mg/m3) usually encountered over the same region during summertime. To assess this anomaly and possible causes, we used a wide range of oceanographical and meteorological datasets, including Chl-a concentrations, sea surface temperature (SST), sea surface height (SSH), mixed layer depth (MLD), ocean current velocity and aerosol optical depth (AOD) obtained from different sensors and models. Findings confirmed this anomalous behavior in the spatial domain using Hovmöller data analysis techniques, while a time series analysis addressed monthly and daily variability. Our analysis suggests that a combination of factors controlling nutrient supply contributed to the anomalous phytoplankton growth. These factors include horizontal transfer of upwelling water through eddy circulation and possible mineral fertilization from atmospheric dust deposition. Coral reefs might have provided extra nutrient supply, yet this is out of the scope of our analysis. We thought that dust deposition from a coastal dust jet event in late June, coinciding with the phytoplankton blooms in the area under investigation, might have also contributed as shown by our AOD findings. However, a lag cross correlation showed a two-month lag between strong dust outbreak and the high Chl-a anomaly. The high Chl-a concentration at the edge of the eddy emphasizes the importance of horizontal advection in fertilizing oligotrophic (nutrient poor) Red Sea waters. [ABSTRACT FROM AUTHOR]

During the twentieth century, the southeast United States cooled, in direct contrast with widespread global and hemispheric warming. While the existing literature is divided on the cause of this so-called "warming hole," anthropogenic aerosols have been hypothesized as playing a primary role in its occurrence. In this study, unique satellite-based observations of aerosol vertical profiles are combined with a one-dimensional radiative transfer model and surface temperature observations to diagnose how major reductions in summertime aerosol burden since 2001 have impacted surface temperatures in the southeast US. We show that a significant improvement in air quality likely contributed to the elimination of the warming hole and acceleration of the positive temperature trend observed in recent years. These reductions coincide with a new EPA rule that was implemented between 2006 and 2010 that revised the fine particulate matter standard downward. Similar to the southeast US in the twentieth century, other regions of the globe may experience masking of long-term warming due to greenhouse gases, especially those with particularly poor air quality [ABSTRACT FROM AUTHOR]

An optimization approach has been developed for simultaneous retrieval of aerosol properties and normalized water-leaving radiance (nLw) from multispectral, multiangular, and polarimetric observations over ocean. The main features of the method are (1) use of a simplified bio-optical model to estimate nLw, followed by an empirical refinement within a specified range to improve its accuracy; (2) improved algorithm convergence and stability by applying constraints on the spatial smoothness of aerosol loading and Chlorophyll a (Chl a) concentration across neighboring image patches and spectral constraints on aerosol optical properties and nLw across relevant bands; and (3) enhanced Jacobian calculation by modeling and storing the radiative transfer (RT) in aerosol/Rayleigh mixed layer, pure Rayleigh-scattering layers, and ocean medium separately, then coupling them to calculate the field at the sensor. This approach avoids unnecessary and time-consuming recalculations of RT in unperturbed layers in Jacobian evaluations. The Markov chain method is used to model RT in the aerosol/Rayleigh mixed layer and the doubling method is used for the uniform layers of the atmosphere–ocean system. Our optimization approach has been tested using radiance and polarization measurements acquired by the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) over the AERONET USC_SeaPRISM ocean site (6 February 2013) and near the AERONET La Jolla site (14 January 2013), which, respectively, reported relatively high and low aerosol loadings. Validation of the results is achieved through comparisons to AERONET aerosol and ocean color products. For comparison, the USC_SeaPRISM retrieval is also performed by use of the Generalized Retrieval of Aerosol and Surface Properties algorithm (Dubovik et al., 2011). Uncertainties of aerosol and nLw retrievals due to random and systematic instrument errors are analyzed by truth-in/truth-out tests with three Chl a concentrations, five aerosol loadings, three different types of aerosols, and nine combinations of solar incidence and viewing geometries. [ABSTRACT FROM AUTHOR]

A fully coupled meteorology-chemistry model (WRF-Chem, the Weather Research and Forecasting model coupled with chemistry) has been configured to conduct quasi-global simulation for 5 years (2010-2014) and evaluated with multiple observation data sets for the first time. The evaluation focuses on the simulation over the trans-Pacific transport region using various reanalysis and observational data sets for meteorological fields and aerosol properties. The simulation generally captures the overall spatial and seasonal variability of satellite retrieved aerosol optical depth (AOD) and absorbing AOD (AAOD) over the Pacific that is determined by the outflow of pollutants and dust and the emissions of marine aerosols. The assessment of simulated extinction Ångström exponent (EAE) indicates that the model generally reproduces the variability of aerosol size distributions as seen by satellites. In addition, the vertical profile of aerosol extinction and its seasonality over the Pacific are also well simulated. The difference between the simulation and satellite retrievals can be mainly attributed to model biases in estimating marine aerosol emissions as well as the satellite sampling and retrieval uncertainties. Compared with the surface measurements over the western USA, the model reasonably simulates the observed magnitude and seasonality of dust, sulfate, and nitrate surface concentrations, but significantly underestimates the peak surface concentrations of carbonaceous aerosol likely due to model biases in the spatial and temporal variability of biomass burning emissions and secondary organic aerosol (SOA) production. A sensitivity simulation shows that the trans-Pacific transported dust, sulfate, and nitrate can make significant contribution to surface concentrations over the rural areas of the western USA, while the peaks of carbonaceous aerosol surface concentrations are dominated by the North American emissions. Both the retrievals and simulation show small interannual variability of aerosol characteristics for 2010-2014 averaged over three Pacific sub-regions. The evaluation in this study demonstrates that the WRF-Chem quasi-global simulation can be used for investigating trans-Pacific transport of aerosols and providing reasonable inflow chemical boundaries for the western USA, allowing one to further understand the impact of transported pollutants on the regional air quality and climate with high-resolution nested regional modeling. [ABSTRACT FROM AUTHOR]

Previous studies showed that, over the global ocean, there is no noticeable hemispheric asymmetry in cloud fraction (CF). This contributes to the balance in solar radiation reaching the sea surface in the northern and southern hemispheres. In the current study, we focus on the tropical Atlantic (30° N–30° S), which is characterized by significant amounts of Saharan dust dominating other aerosol species over the North Atlantic. Our main point is that, over the tropical Atlantic, Saharan dust not only is responsible for the pronounced hemispheric aerosol asymmetry, but also contributes to significant cloud cover along the Saharan Air Layer (SAL). Over the tropical Atlantic in July, along the SAL, Moderate Resolution Imaging Spectroradiometer CF data showed significant cloud cover (up to 0.8–0.9). This significant CF along SAL together with clouds over the Atlantic Intertropical Convergence Zone contributes to the 20% hemispheric CF asymmetry. This leads to the imbalance in strong solar radiation, which reaches the sea surface between the tropical North and South Atlantic, and, consequently, affects climate formation in the tropical Atlantic. During the 10-year study period (July 2002–June 2012), NASA Aerosol Reanalysis (aka MERRAero) showed that, when the hemispheric asymmetry in dust aerosol optical thickness (AOT) was most pronounced (particularly in July), dust AOT averaged separately over the tropical North Atlantic was one order of magnitude higher than that averaged over the tropical South Atlantic. In the presence of such strong hemispheric asymmetry in dust AOT in July, CF averaged separately over the tropical North Atlantic exceeded that over the tropical South Atlantic by 20%. Both Multiangle Imaging Spectroradiometer measurements and MERRAero data were in agreement on seasonal variations in hemispheric aerosol asymmetry. Hemispheric asymmetry in total AOT over the Atlantic was most pronounced between March and July, when dust presence over the North Atlantic was maximal. In September and October, there was no noticeable hemispheric aerosol asymmetry between the tropical North and South Atlantic. During the season with no noticeable hemispheric aerosol asymmetry, we found no noticeable asymmetry in cloud cover. [ABSTRACT FROM PUBLISHER]

Background: Systemic juvenile idiopathic arthritis (SoJIA) is the most striking form of juvenile idiopathic arthritis. The aim of our study was to evaluate the clinical responses and outcomes of children with SoJIA to IL-6 blockade using two different tocilizumab (TCZ) treatment protocols designed for milder and more severe SoJIA patient groups, and evaluate the possibility of achieving biologic-free remission. Methods: Thirty-seven active SoJIA children who have failed treatment with corticosteroids and other DMARDs were included in our retrospective study. TCZ doses were prescribed in two treatment approaches: every 2 weeks TCZ dosing (Q2W) and every 4 weeks TCZ dosing (Q4W). The patients were assigned to these two groups by the study physicians depending on the severity of the SoJIA disease as judged by each clinician. Results: Thirty-three of the 37 children successfully completed the trial. TCZ was discontinued in 11patients during the trial. Seven children achieved inactive disease and were allowed to stop the TCZ and 4 had severe adverse events requiring drug cessation. Currently 7 patients continue to have TCZ-free remission [4/7 remission off-medication, 3/7still on methotrexate (MTX)]. This mixed group had a median treatment duration of 1002 days. The children in remission off of all medications, TCZ and MTX, had a median remission duration of 1162 days (ranged 932-1301 days). Compared to the patients assigned to the Q2W TCZ treatment group, the patients assigned to the Q4W TCZ group had a milder SoJIA course. The patients had higher levels of hemoglobin, total proteins, and serum albumins. They had lower white blood cell counts (WBC), % granulocytes, CRP, ESR, ferritins, and LDH. These children had a lower frequency of internal organ involvement, fewer relapses during TCZ treatment, and no macrophage activation syndrome episodes. Conclusions: Our experience with TCZ for SoJIA supports the excellent result of other studies. What may be novel is our finding that thisIL-6 blockade with TCZ may be able to be utilized at a less frequent dosing schedule in mild SoJIA compared to severe SoJIA. We discuss other factors that may increase the probability of a patient reaching TCZ-free remission. [ABSTRACT FROM AUTHOR]

ABSTRACT The effects of El Niño/Southern Oscillation ( ENSO) under negative Arctic Oscillation ( AO) phase on the Asian dust activity are investigated for springs of the period 1961-2002. The spring dust index ( DI) describing the monthly frequencies of three types of dust events (e.g. dust storm, blowing dust, and floating dust) exhibits a significant increase in the years of negative AO phase (hereafter AO−) and El Niño, compared with that in the years of AO− and La Niña. Averaged over all observation stations, the spring DI (49.7) during the El Niño/ AO− years is higher by 11.4% or 29.8% than that (38.3) during the La Niña/ AO− years. We suggest possible physical mechanism that the anomalous large-scale environments associated with AO− and El Niño are more effective to provide favourable conditions to enhance Asian dust activity. During the El Niño/ AO− years, meridional gradients of pressure and temperature over the dust source regions are significantly enhanced by decreasing the geopotential height and warming air temperature that originated from the north and south of source regions, respectively, under the influence of AO− and El Niño. These also intensify the zonal wind shear and atmospheric baroclinicity, thereby producing enhanced cyclogenesis and dust occurrences over the major source regions. At the same time, dust transport paths with the stronger westerly winds are developed by the combined constraints of anomalous cyclone over the Siberia and the Mongolia and anomalous anticyclone over the western North Pacific, and thus strengthen dust transport to the downwind regions. [ABSTRACT FROM AUTHOR]

The effects of El Niño/Southern Oscillation (ENSO) under negative Arctic Oscillation (AO) phase on the Asian dust activity are investigated for springs of the period 1961-2002. The spring dust index (DI) describing the monthly frequencies of three types of dust events (e.g. dust storm, blowing dust, and floating dust) exhibits a significant increase in the years of negative AO phase (hereafter AO-) and El Niño, compared with that in the years of AO- and La Niña. Averaged over all observation stations, the spring DI (49.7) during the El Niño/AO- years is higher by 11.4% or 29.8% than that (38.3) during the La Niña/AO- years. We suggest possible physical mechanism that the anomalous large-scale environments associated with AO- and El Niño are more effective to provide favourable conditions to enhance Asian dust activity. During the El Niño/AO- years, meridional gradients of pressure and temperature over the dust source regions are significantly enhanced by decreasing the geopotential height and warming air temperature that originated from the north and south of source regions, respectively, under the influence of AO- and El Niño. These also intensify the zonal wind shear and atmospheric baroclinicity, thereby producing enhanced cyclogenesis and dust occurrences over the major source regions. At the same time, dust transport paths with the stronger westerly winds are developed by the combined constraints of anomalous cyclone over the Siberia and the Mongolia and anomalous anticyclone over the western North Pacific, and thus strengthen dust transport to the downwind regions. [ABSTRACT FROM AUTHOR]

Background: Systemic juvenile idiopathic arthritis (SoJIA) is the most striking form of juvenile idiopathic arthritis. The aim of our study was to evaluate the clinical responses and outcomes of children with SoJIA to IL-6 blockade using two different tocilizumab (TCZ) treatment protocols designed for milder and more severe SoJIA patient groups, and evaluate the possibility of achieving biologic-free remission. Methods: Thirty-seven active SoJIA children who have failed treatment with corticosteroids and other DMARDs were included in our retrospective study. TCZ doses were prescribed in two treatment approaches: every 2 weeks TCZ dosing (Q2W) and every 4 weeks TCZ dosing (Q4W). The patients were assigned to these two groups by the study physicians depending on the severity of the SoJIA disease as judged by each clinician. Results: Thirty-three of the 37 children successfully completed the trial. TCZ was discontinued in 11patients during the trial. Seven children achieved inactive disease and were allowed to stop the TCZ and 4 had severe adverse events requiring drug cessation. Currently 7 patients continue to have TCZ-free remission [4/7 remission off-medication, 3/7still on methotrexate (MTX)]. This mixed group had a median treatment duration of 1002 days. The children in remission off of all medications, TCZ and MTX, had a median remission duration of 1162 days (ranged 932-1301 days). Compared to the patients assigned to the Q2W TCZ treatment group, the patients assigned to the Q4W TCZ group had a milder SoJIA course. The patients had higher levels of hemoglobin, total proteins, and serum albumins. They had lower white blood cell counts (WBC), % granulocytes, CRP, ESR, ferritins, and LDH. These children had a lower frequency of internal organ involvement, fewer relapses during TCZ treatment, and no macrophage activation syndrome episodes. Conclusions: Our experience with TCZ for SoJIA supports the excellent result of other studies. What may be novel is our finding that this IL-6 blockade with TCZ may be able to be utilized at a less frequent dosing schedule in mild SoJIA compared to severe SoJIA. We discuss other factors that may increase the probability of a patient reaching TCZ-free remission. [ABSTRACT FROM AUTHOR]

Background: Systemic juvenile idiopathic arthritis (SoJIA) is the most striking form of juvenile idiopathic arthritis. The aim of our study was to evaluate the clinical responses and outcomes of children with SoJIA to IL-6 blockade using two different tocilizumab (TCZ) treatment protocols designed for milder and more severe SoJIA patient groups, and evaluate the possibility of achieving biologic-free remission. Methods: Thirty-seven active SoJIA children who have failed treatment with corticosteroids and other DMARDs were included in our retrospective study. TCZ doses were prescribed in two treatment approaches: every 2 weeks TCZ dosing (Q2W) and every 4 weeks TCZ dosing (Q4W). The patients were assigned to these two groups by the study physicians depending on the severity of the SoJIA disease as judged by each clinician. Results: Thirty-three of the 37 children successfully completed the trial. TCZ was discontinued in 11patients during the trial. Seven children achieved inactive disease and were allowed to stop the TCZ and 4 had severe adverse events requiring drug cessation. Currently 7 patients continue to have TCZ-free remission [4/7 remission off-medication, 3/7still on methotrexate (MTX)]. This mixed group had a median treatment duration of 1002 days. The children in remission off of all medications, TCZ and MTX, had a median remission duration of 1162 days (ranged 932-1301 days). Compared to the patients assigned to the Q2W TCZ treatment group, the patients assigned to the Q4W TCZ group had a milder SoJIA course. The patients had higher levels of hemoglobin, total proteins, and serum albumins. They had lower white blood cell counts (WBC), % granulocytes, CRP, ESR, ferritins, and LDH. These children had a lower frequency of internal organ involvement, fewer relapses during TCZ treatment, and no macrophage activation syndrome episodes. Conclusions: Our experience with TCZ for SoJIA supports the excellent result of other studies. What may be novel is our finding that thisIL-6 blockade with TCZ may be able to be utilized at a less frequent dosing schedule in mild SoJIA compared to severe SoJIA. We discuss other factors that may increase the probability of a patient reaching TCZ-free remission. [ABSTRACT FROM AUTHOR]

Background Systemic juvenile idiopathic arthritis (SoJIA) is the most striking form of juvenile idiopathic arthritis. The aim of our study was to evaluate the clinical responses and outcomes of children with SoJIA to IL-6 blockade using two different tocilizumab (TCZ) treatment protocols designed for milder and more severe SoJIA patient groups, and evaluate the possibility of achieving biologic-free remission. Methods Thirty-seven active SoJIA children who have failed treatment with corticosteroids and other DMARDs were included in our retrospective study. TCZ doses were prescribed in two treatment approaches: every 2 weeks TCZ dosing (Q2W) and every 4 weeks TCZ dosing (Q4W). The patients were assigned to these two groups by the study physicians depending on the severity of the SoJIA disease as judged by each clinician. Results Thirty-three of the 37 children successfully completed the trial. TCZ was discontinued in 11patients during the trial. Seven children achieved inactive disease and were allowed to stop the TCZ and 4 had severe adverse events requiring drug cessation. Currently 7 patients continue to have TCZ-free remission [4/7 remission off-medication, 3/7still on methotrexate (MTX)]. This mixed group had a median treatment duration of 1002 days. The children in remission off of all medications, TCZ and MTX, had a median remission duration of 1162 days (ranged 932-1301 days). Compared to the patients assigned to the Q2W TCZ treatment group, the patients assigned to the Q4W TCZ group had a milder SoJIA course. The patients had higher levels of hemoglobin, total proteins, and serum albumins. They had lower white blood cell counts (WBC), % granulocytes, CRP, ESR, ferritins, and LDH. These children had a lower frequency of internal organ involvement, fewer relapses during TCZ treatment, and no macrophage activation syndrome episodes. Conclusions Our experience with TCZ for SoJIA supports the excellent result of other studies. What may be novel is our finding that thisIL-6 blockade with TCZ may be able to be utilized at a less frequent dosing schedule in mild SoJIA compared to severe SoJIA. We discuss other factors that may increase the probability of a patient reaching TCZ-free remission. [ABSTRACT FROM AUTHOR]

Public health professionals are increasingly concerned about the potential impact that climate variability and change can have on infectious disease. The International Research Institute for Climate and Society (IRI) is developing new products to increase the public health community’s capacity to understand, use and demand the appropriate climate data and climate information to mitigate the public health impacts of climate on infectious disease, in particular meningitis and malaria. In this paper, we present the new and improved products that have been developed for: (i) estimating dust aerosol for forecasting risks of meningitis and (ii) for monitoring temperature and rainfall and integrating them into a vectorial capacity model for forecasting risks of malaria epidemics. We also present how the products have been integrated into a knowledge system (IRI Data Library Map Room, SERVIR) to support the use of climate and environmental information in climate-sensitive health decision-making. [ABSTRACT FROM PUBLISHER]

The lignocellulosic perennial crop miscanthus, especially Miscanthus × giganteus, is particularly interesting for bioenergy production as it combines high biomass production with low environmental impact. However, there are several varieties that pose a hazard due to susceptibility to disease. This review contains links showing genotype and ecological variability of important characteristics related to yield and biomass composition of miscanthus that may be useful in plant breeding programs to increase bioenergy production. Some clones of Miscanthus × giganteus and Miscanthus sinensis are particularly interesting due to their high biomass production per hectare. Although the compositional requirements for industrial biomass have not been fully defined for the various bioenergy conversion processes, the lignin-rich species Miscanthus × giganteus and Miscanthus sacchariflorus seem to be more suitable for thermochemical conversion processes. At the same time, the species Miscanthus sinensis and some clones of Miscanthus × giganteus with low lignin content are of interest for the biochemical transformation process. The species Miscanthus sacchariflorus is suitable for various bioenergy conversion processes due to its low ash content, so this species is also interesting as a pioneer in breeding programs. Mature miscanthus crops harvested in winter are favored by industrial enterprises to improve efficiency and reduce processing costs. This study can be attributed to other monocotyledonous plants and perennial crops that can be used as feedstock for biofuels. [ABSTRACT FROM AUTHOR]

Background: The Wnt/β-catenin signalling is aberrantly activated in primary B cell chronic lymphocytic leukaemia (CLL). Epigenetic silencing of pathway inhibitor genes may be a mechanism for its activation. In this study, we investigated systematically and quantitatively the methylation status of 12 Wnt/β-catenin pathway inhibitor genes – CDH1, DACT1, DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 and WIF1 – in the cell lines EHEB and MEC-1 as well as patient samples. Methods: Quantification of DNA methylation was performed by means of bisulphite pyrosequencing and confirmed by bisulphite Sanger sequencing. Gene expression was analysed by qPCR using GAPDH as internal control. E-cadherin and β-catenin protein quantification was carried out by microsphere-based immunoassays. Methylation differences observed between the patient and control groups were tested using generalised least squares models. Results: For 10 genes, a higher methylation level was observed in tumour material. Only DKK4 exhibited similarly high methylation levels in both tumour and normal specimens, while DACT1 was always essentially unmethylated. However, also for these inhibitors, treatment of cells with the demethylating agent 5-aza-2´-deoxycytidine resulted in an induction of their expression, as shown by quantitative PCR, suggesting an indirect epigenetic control of activity. While the degree of demethylation and its transcriptional consequences differed between the genes, there was an overall high correlation of demethylation and increased activity. Protein expression studies revealed that no constitutive Wnt/β-catenin signalling occurred in the cell lines, which is in discrepancy with results from primary CLL. However, treatment with 5-aza-2´-deoxycytidine caused accumulation of β-catenin. Simultaneously, E-cadherin expression was strongly induced, leading to the formation of a complex with β-catenin and thus demonstrating its epigenetically regulated inhibition effect. Conclusions: The results suggest an epigenetic silencing mechanism of the Wnt/&# 946;-catenin pathway inhibitor genes in CLL. Hypermethylation and silencing of functionally related genes may not be completely stochastic but result from the tumour epigenome reprogramming orchestrated by Polycomb-group repressive complexes. The data are of interest in the context of epigenetic-based therapy. [ABSTRACT FROM AUTHOR]

Exposure to fine particulate matter (PM 2.5 ) air pollution has been shown in numerous studies to be associated with detrimental health effects. However, the ability to conduct epidemiological assessments can be limited due to challenges in generating reliable PM 2.5 estimates, particularly in parts of the world such as the Middle East where measurements are scarce and extreme meteorological events such as sandstorms are frequent. In order to supplement exposure modeling efforts under such conditions, satellite-retrieved aerosol optical depth (AOD) has proven to be useful due to its global coverage. By using AODs from the Multiangle Implementation of Atmospheric Correction (MAIAC) of the MODerate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging Spectroradiometer (MISR) combined with meteorological and assimilated aerosol information from the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), we constructed machine learning models to predict PM 2.5 in the area surrounding the Persian Gulf, including Kuwait, Bahrain, and the United Arab Emirates (U.A.E). Our models showed regional differences in predictive performance, with better results in the U.A.E. (median test R 2 = 0.66) than Kuwait (median test R 2 = 0.51). Variable importance also differed by region, where satellite-retrieved AOD variables were more important for predicting PM 2.5 in Kuwait than in the U.A.E. Divergent trends in the temporal and spatial autocorrelations of PM 2.5 and AOD in the two regions offered possible explanations for differences in predictive performance and variable importance. In a test of model transferability, we found that models trained in one region and applied to another did not predict PM 2.5 well, even if the transferred model had better performance. Overall the results of our study suggest that models developed over large geographic areas could generate PM 2.5 estimates with greater uncertainty than could be obtained by taking a regional modeling approach. Furthermore, development of methods to better incorporate spatial and temporal autocorrelations in machine learning models warrants further examination. [ABSTRACT FROM AUTHOR]

• Successive order of scattering (SOS) simulation of radiance and polarimetry factors for atmospheric carbonaceous aerosol. • Simulations performed at wavelengths corresponding to NASA's AirMSPI's polarimetric bands. • Compared to black carbon aerosol, the radiance- and polarimetry-based reflectance factors of brown carbon aerosol are more sensitive to changes in particle size and imaginary refractive index. • Degree of Linear Polarization (DoLP) is most sensitive to changes in particle imaginary refractive index below 0.4. • Particle size distributions modulate the level of DoLP's sensitivity to imaginary refractive index. Visible-light-absorbing carbonaceous aerosols within the boundary layer affect the radiance and polarization states of the radiation at the top of the atmosphere. Remote sensing from suborbital and satellite-based platforms utilizes these radiance and polarization signals to retrieve the key properties of these aerosols. Recent retrieval algorithms have shown a progressive trend toward including multi-angular and multi-spectral polarimetric measurements to produce better retrieval accuracy in comparison to those using measurements based on a single viewing angle. Here, we perform a theoretical investigation of the top of atmosphere (TOA) radiance-related reflectance factor (bidirectional reflectance factor (BRF)) and the two types of polarimetry-related factors (polarized bidirectional reflectance factor (pBRF) and the degree of linear polarization (DoLP)) for different types of atmospheric light-absorbing carbonaceous aerosols as a function of particle size distribution. We selected three polarimetric bands corresponding to those utilized by NASA's Airborne Multiangle SpectroPolarimetric Imager (AirMSPI)—near-UV (470 nm), visible (660 nm), and near-infrared (865 nm)—for our simulations which were performed over ocean surface using the successive order of scattering (SOS) algorithm coupled to a Lorenz-Mie aerosol optics model. The analysis of particle phase matrix elements indicates a close relationship between the angular dependencies of DoLP and associated phase matrix components at the shortest polarimetric band (470 nm). Using Jacobian analysis, we find that the radiance- and polarimetry-related reflectance factors of weakly light-absorbing aerosols, such as brown carbon, are more sensitive to changes in particle size and imaginary refractive index in comparison with those of black carbon, which is strongly light-absorbing. Our results suggest that the DoLP data could be used by future retrieval algorithms for reliably estimating microphysical properties of absorbing carbonaceous aerosols with imaginary refractive index less than 0.4. [ABSTRACT FROM AUTHOR]

The present study summarizes two decades (2000–2019) of climatology and trends in aerosol loading and optical properties using a high spatial resolution data obtained from NASA's MODIS MAIAC and MISR aerosol products supplemented by moderate resolution aerosol data from OMI sensor over South Asia (SA). MISR AOD showed good agreement against AERONET AOD with 68.68% of the retrievals falling within the expected error and high Pearson's correlation coefficient (R = 0.83). The 20 years geometric mean of MAIAC and MISR AOD revealed higher loading of aerosols over the Indo-Gangetic Plain (IGP) and Eastern coast of India by 30% to 44% compared to the mean AOD over the entire SA. The highest mean AOD under cloud-free conditions was noted during monsoon season, followed by pre-monsoon, post-monsoon, and winter. The high contribution of coarse-mode AOD (cAOD) mainly from natural aerosol emission and small-mode AOD (sAOD) from local anthropogenic emissions are the main driver to high AOD in monsoon and pre-monsoon seasons. Besides, the presence of high humidity during the monsoon season favors the hygroscopic growth of the particles and leads to higher AOD values over SA. The high spatial resolutions of MODIS/MAIAC and MISR aerosol products enabled the identification of previously unobserved aerosol hotspots over Bihar, West Bengal, and the eastern Indian coastal state of Odisha, which is mainly dominated by small aerosol particles. The contributions of smaller aerosol particles to the total aerosol loading were found to be higher during post-monsoon and winter over most states in India, Nepal, and Bangladesh. In contrast, the contribution of coarser particles was higher over Pakistan during pre-monsoon and monsoon seasons. Smaller particles were predominantly retrieved over the Indian states dominated by mining industries, including Jharkhand and Odisha. A typical dominance of absorbing carbonaceous aerosols was also noted over the northwestern region of IGP during post-monsoon, which otherwise was mainly affected by mixed dust aerosols and carbonaceous aerosols in pre-monsoon and monsoon seasons. A statistically significant positive temporal trend in AOD was observed for the whole study period, over most of the SA region, which was influenced by the increase in small particles over India and Bangladesh. Urban/industrial weakly absorbing aerosols were found to be the main contributor to a similarly positive trend over Central India and East coast Indian states. Overall, recent advancements in high spatial resolution satellite-based aerosol optical properties showed good potential to identify the aerosol hotspots and constrain aerosol types across a highly polluted SA region. • The latest MISR V23 AOD product showed promising agreement with ground observations. • Significant positive trends in MISR and MAIAC AOD are identified over South Asia. • Climatological trends recognize the Eastern Indian coast as a new aerosol hotspot. • Small aerosol particles contribute to >54% of the total AOD in all seasons. • Anthropogenic sources are the major contributor to high aerosol loading over SA. [ABSTRACT FROM AUTHOR]

Characterization of aerosol vertical distribution in the planetary boundary layer (PBL) using passive remote sensing requires advances in the current state of the art. To quantify the performance of various passive sensor designs within a common framework we developed an aerosol climatology of the Los Angeles basin and applied observing system simulation experiments (OSSEs) to estimate the information content retrievable from a variety of sensors measuring reflected near-infrared solar radiation. In addition to simulating current and planned satellite sensors, we also characterize the sensitivity of the California Laboratory for Atmospheric Remote Sensing – Fourier Transform Spectrometer (CLARS-FTS), located at Mt. Wilson (1.67 km above sea level), which is utilized in this work as a testbed for aerosol profiling remote sensing. We estimate the impacts of spectral coverage, radiance and polarization, spectral resolution, signal to noise ratio (SNR), and number of viewing angles on the information content and retrieval uncertainties of aerosol profiles in the PBL. We found that by adding high spectral resolution (full-width half-maximum of 3 cm−1 or better), polarimetric measurements with a SNR of at least 212 to radiance measurements with SNR of 300 for both O 2 A and 1∆ bands, the degrees of freedom for signal (DOFS) of a single CLARS-FTS measurement is raised from 2.1 to 2.8. This improvement is sufficient to simultaneously quantify three key parameters: aerosol optical depth, aerosol peak height, and aerosol layer thickness in the PBL. Current satellite-borne instruments (OCO-2, OCO-3, TEMPO, TROPOMI, and EPIC) and planned instruments (TEMPO, MicroCarb, SPEXone, and MAIA), individually provide a DOFS ≤ 2.25, which is insufficient to simultaneously quantify all three aerosol profiling parameters in the PBL. Joint radiometric and polarimetric measurements of the O 2 A and B bands with 3 cm−1 spectral resolution, SNR of 500 for radiance and 353 for polarization, acquired at three viewing angles, can provide sufficient sensitivity to retrieve the three aerosol parameters simultaneously. The inclusion of high spectral resolution radiometric and polarimetric measurements reduces the required number of viewing angles, which is advantageous when the multiangular data are acquired with a pointable instrument. In this case a larger number of viewing angles reduces the spatial coverage that can be achieved for a given target. • Aerosol profiling in the planetary boundary layer (PBL) using O 2 bands are studied. • Current satellite sensors' sensitivity is insufficient for PBL's aerosol profiling. • Combining multiple angles and polarization with high resolution achieves the goal. [ABSTRACT FROM AUTHOR]

Many air pollution health effects studies rely on exposure estimates of particulate matter (PM) concentrations derived from remote sensing observations of aerosol optical depth (AOD). Simple but robust calibration models between AOD and PM are therefore important for generating reliable PM exposures. We conduct an in-depth examination of the spatial and temporal characteristics of the AOD-PM2.5 relationship by leveraging data from the Distributed Regional Aerosol Gridded Observation Networks (DRAGON) field campaign where eight NASA Aerosol Robotic Network (AERONET) sites were co-located with EPA Air Quality System (AQS) monitoring sites in California's Central Valley from November 2012 to April 2013. With this spatiotemporally rich data we found that linear calibration models (R2 = 0.35, RMSE = 10.38 μg/m3) were significantly improved when spatial (R2 = 0.45, RMSE = 9.54 μg/m3), temporal (R2 = 0.62, RMSE = 8.30 μg/m3), and spatiotemporal (R2 = 0.65, RMSE = 7.58 μg/m3) functions were included. As a use-case we applied the best spatiotemporal model to convert space-borne MultiAngle Imaging Spectroradiometer (MISR) AOD observations to predict PM2.5 over the region (R2 = 0.60, RMSE = 8.42 μg/m3). Our results imply that simple AERONET AOD-PM2.5 calibrations are robust and can be reliably applied to space-borne AOD observations, resulting in PM2.5 prediction surfaces for use in downstream applications. [ABSTRACT FROM AUTHOR]