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Egg waste is a major contributor to global food waste, accounting for 15% of discarded food in the United States. Typically, eggs have a shorter shelf life at room temperature and are preserved in refrigeration from production to consumption. However, maintaining constant refrigeration is energy‐intensive and expensive. Here, a bionanocomposite coating has been developed that incorporates each element of eggs – egg white, yolk, and eggshell – to increase the shelf life of fresh eggs without requiring further refrigeration. The quality of eggs has been successfully preserved for up to three weeks at room temperature. The coated eggs maintain the highest grade (AA) and exhibit improved Haugh Unit (HU), Yolk Index (YI), and pH compared to uncoated eggs. The coating reduces weight loss by ≈37% with an increase in HU (≈12.5%) and YI (≈13.9%). Morphological analysis reveals strong adhesion of the coating to the eggshell surface, showcasing promising barrier properties. The coating demonstrates an optimal combination of oxygen permeability (≈12.2 cm3 µm m−2 d−1 kPa−1) and water vapor transmission (≈31.5 g mm m−2 per day) with excellent antimicrobial properties. Overall, this approach of repurposing eggs into a high‐performance coating shows a promising viable alternative to refrigeration and a solution to combat egg waste. [ABSTRACT FROM AUTHOR]

US probable maximum precipitation (PMP) estimation guidance fundamentally relies on the assumption that any change in precipitable water is consistent with the change in precipitation. While this assumption is theoretically sound in extreme storms that are convective in nature with lifting so vigorous as to convert all available atmospheric water vapor into precipitation, this type of storm rarely occurs in the Pacific Northwest of the United States; the assumption may be invalid. This study investigates the relationship between changes in precipitable water and changes in precipitation using high-resolution model-based precipitation maximization for a large number of atmospheric river (AR) events impacting the Columbia River Basin (CRB) in the Pacific Northwest. Analysis indicates that the relationship between changes in precipitable water and changes in precipitation cannot be simply approximated as either 1∶1 (i.e., consistent) or a linear relationship (R=0.13 ; p=0.17). Our analysis on the precipitation maximization results showed that the horizontal wind speed at 10m plays an important role in determining the relationship between these changes. The relationship between integrated water vapor transport (IVT) change and precipitation change was found to be stronger (R=0.47) and statistically significant (p<0.01) for storms impacting the CRB, which was approximated as precipitation change = 2.0 × IVT change −0.6. Our finding underscores the importance of considering not only atmospheric water vapor amounts but also the accompanying flows transporting atmospheric water vapor, in maximizing precipitation depths over a target region. [ABSTRACT FROM AUTHOR]

The global increase in atmospheric water vapor due to climate change tends to heighten the dangers associated with both humid heat and heavy precipitation. Process-linked connections between these two extremes, particularly those which cause them to occur close together in space or time, are of special concern for impacts. Here we investigate how atmospheric rivers relate to the risk of summertime humid heat in the United States. We find that the hazards of atmospheric rivers and humid heat often occur in close proximity, most notably across the northern third of the United States. In this region, high levels of water vapor – resulting from the spatially organized horizontal moisture plumes that characterize atmospheric rivers – act to amplify humid heat, generally during the transition from dry high-pressure ridge conditions to wet low-pressure trough conditions. In contrast, the US Southeast, Southwest, and Northwest tend to experience atmospheric rivers and humid heat separately, representing an important negative correlation of joint risk. [ABSTRACT FROM AUTHOR]

Water vapor's contribution to Earth's radiative forcing is most sensitive to changes in its lower stratosphere concentration. One recognized pathway for rapid increases in stratospheric water vapor is tropopause‐overshooting convection. Since this pathway has been rarely sampled, the NASA Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) field project focused on obtaining in situ observations of stratospheric air recently affected by convection over the United States. This study reports on the extreme altitudes to which convective hydration was observed. The data show that the overworld stratosphere is routinely hydrated by convection and that past documented records of stratospheric heights of convective hydration were exceeded during several DCOTSS flights. The most extreme event sampled is highlighted, for which stratospheric water vapor was increased by up to 26% at an altitude of 19.25 km, a potential temperature of 463 K, and an ozone mixing ratio >1500 ppbv. Plain Language Summary: When thunderstorms reach into the second layer of the atmosphere above Earth's surface, the stratosphere, they may impact the concentration and distribution of trace gases that are important to chemistry and climate. One gas that is routinely affected during these events is water vapor, which is typically scarce in the stratosphere. This study presents new aircraft observations of extreme heights in the stratosphere moistened by these thunderstorms. Since increases in stratospheric water vapor positively contribute to warming of Earth's climate and can activate chemistry that destroys ozone, better understanding of this phenomenon helps refine our understanding of its role in the climate system. The new aircraft observations provide clear evidence that water vapor is enhanced by thunderstorms at higher levels in the stratosphere than previously recognized. Key Points: Tropopause‐overshooting convection in the United States hydrates the stratosphere to exceptional heightsObservations of the height of stratospheric convective hydration during the Dynamics and Chemistry of the Summer Stratosphere field campaign exceed all prior global recordsThe overworld stratosphere is routinely hydrated by midlatitude overshooting convection [ABSTRACT FROM AUTHOR]

The global increase in atmospheric water vapour due to climate change tends to heighten the dangers associated with both humid heat and heavy precipitation. Process-linked correlations between these two extremes, particularly those which cause them to occur close together in space or time, are of special concern for efforts to understand and mitigate their impacts. Here we investigate how atmospheric rivers relate to the risk of summertime humid heat in the US. We find that the hazards of atmospheric rivers and humid heat often occur in close proximity, most notably across the northern third of the US. In this region, high levels of water vapour — resulting from the spatially organised horizontal moisture plumes that characterise atmospheric rivers — act to amplify humid heat, generally during the transition from dry high-pressure ridge conditions to wet low-pressure trough conditions. In contrast, the Southeast, Southwest, and Northwest US tend to experience atmospheric rivers and humid heat separately, representing an important negative correlation of joint risk. [ABSTRACT FROM AUTHOR]

The National Ecological Observatory Network (NEON) provides open-access measurements of stable isotope ratios in atmospheric water vapor (δ2H, δ18O) and carbon dioxide (δ13C) at different tower heights, as well as aggregated biweekly precipitation samples (δ2H, δ18O) across the United States. These measurements were used to create the NEON Daily Isotopic Composition of Environmental Exchanges (NEON-DICEE) dataset estimating precipitation (P; δ2H, δ18O), evapotranspiration (ET; δ2H, δ18O), and net ecosystem exchange (NEE; δ13C) isotope ratios. Statistically downscaled precipitation datasets were generated to be consistent with the estimated covariance between isotope ratios and precipitation amounts at daily time scales. Isotope ratios in ET and NEE fluxes were estimated using a mixing-model approach with calibrated NEON tower measurements. NEON-DICEE is publicly available on HydroShare and can be reproduced or modified to fit user specific applications or include additional NEON data records as they become available. The NEON-DICEE dataset can facilitate understanding of terrestrial ecosystem processes through their incorporation into environmental investigations that require daily δ2H, δ18O, and δ13C flux data. Measurement(s) stable isotope ratios in carbon dioxide • stable isotope ratios in atmospheric water vapor • stable isotope ratios in precipitation Technology Type(s) eddy covariance towers • wet deposition collector Factor Type(s) location Sample Characteristic - Environment climate system Sample Characteristic - Location United States of America [ABSTRACT FROM AUTHOR]

It has been known that the southwestern United States (US) has experienced a drying trend during spring as climate warms. Less is known about the projected increase of summer precipitation in the region and its physical mechanisms. By using climate model simulations and moisture budget analysis, we show that in contrast to the spring, the changes of moisture gradient and wind convergence both cause increasing precipitation during summer. The change of the moisture gradient is featured by larger increase of water vapor along the western coast than inland, thus causing enhanced moisture advection in the future climate. The change of the wind convergence is caused by the maximum jet weakening over the continental US near the latitudes of the region, which leads to enhanced moisture convergence. Plain Language Summary: Precipitation in the southwestern United States (US) is projected to decrease in the spring but increase in the summer under climate warming. It has been known that the spring dry is caused by enhanced zonal drying advection. Here, we performed moisture budget analysis using climate model simulations and found that in contrast to the spring, the moisture gradient change and the wind convergence change both increase the precipitation in the summer. There is more moisture increase along the western coast than inland in the summer. Hence the westerly brings more moisture into the southwestern US and increases precipitation. There is more wind convergence with warming during summer in the southwestern US, which induces more moisture convergence and hence more precipitation. Such wind convergence increase is associated with the maximum jet weakening over land near the southwestern US. Spring drying and summer wetting in the southwestern US demonstrate how different changes of atmospheric dynamics and thermodynamics in different seasons determine the precipitation change. Key Points: Precipitation decreases during spring but increases during summer in the southwestern United States in response to warmingEnhanced zonal moisture advection causes moisture convergence in the summerStronger wind convergence associated with jet weakening is mainly responsible for the summer precipitation increase [ABSTRACT FROM AUTHOR]

Snowmelt is an essential process for the health and sustenance of numerous communities and ecosystems across the globe, though it also presents potential hazards when ablation processes are exceedingly rapid. Using 4-km daily snow water equivalent, temperature, and precipitation data for three decades (1988–2017), here we provide a broad characterization of extreme snowmelt episodes over the conterminous United States in terms of magnitude, timing, and coincident synoptic weather patterns. Larger-magnitude extreme snowmelt events usually coincide with minimal precipitation and elevated temperatures. However, certain regions, particularly mountainous regions and the northeastern United States, exhibit greater likelihood of extreme snowmelt events during pronounced rain-on-snow events. During snowmelt extremes, snowmelt rate often exceeds precipitation in many regions. Meteorological patterns and associated water vapor transport most directly connected to extreme events over different regions are classified via a machine-learning technique. Over the 30-yr study period, there is a weakly increasing trend in the frequency of extremes, though this does not necessarily signify an increase in snowmelt magnitudes. [ABSTRACT FROM AUTHOR]

An analysis of 3,104 stations in the United States shows virtually every station exhibits a positive correlation between precipitable water (PW) and extreme daily precipitation (EP) with over one‐third statistically significant. To first approximation, EP scales linearly with PW, but there is nonlinear scaling at the lower and upper ends of the PW distribution. On average, EP is amplified by twice the amount of PW, but there is substantial seasonal and spatial variability caused by dynamically forced vertical velocity with stations ranging from a one‐to‐one relationship to over three‐to‐one. These latter stations are generally found in elevated terrain or near coasts and in regions and seasons affected by strong synoptic‐scale weather systems. The results also point to PW, not vertical velocity, as the key limiting factor in the most intense EP events. This has important implications for projecting changes of the most intense EP events in a warmer world. Plain Language Summary: As the climate warms, water vapor is increasing in the atmosphere. Analysis of the historical observations of extreme daily precipitation shows that precipitation amounts increase with more water vapor in the atmosphere. On average, extreme daily precipitation amounts equate to twice the amount of water vapor. There is, however, considerable spatial and seasonal variability affected by the predominant weather types in the region, orography, and proximity to oceans. The analysis indicates that when the amount of atmospheric water vapor is high, as occurs during the warm season and in the south and eastern portions of the United States, the increase in extreme precipitation for a given increase in water vapor becomes disproportionately large compared to the same increase at low amounts of water vapor. Water vapor is a limiting factor in the amount of extreme precipitation more often than the intensity of the weather causing the event. Key Points: Extreme daily precipitation is strongly correlated with and on average amplified to twice the vertically integrated water vaporAs water vapor increases there is evidence for nonlinear scaling at lower (higher) values of q with decreasing (increasing) amplificationVertical velocity and related weather types modulate the amplification along with complex terrain and along ocean/land transitions [ABSTRACT FROM AUTHOR]

Atmospheric rivers (ARs) significantly influence precipitation and hydrologic variability inmany areas of the world, including the westernUnited States. AsARs are increasingly recognized by the research community and the public, there is a need to more precisely quantify and communicate their hydrologic impacts, which can vary fromhazardous to beneficial depending on location and on the atmospheric and land surface conditions prior to and during the AR. This study leverages 33 years of atmospheric and hydrologic data for the western United States to 1) identify how water vapor amount, wind direction and speed, temperature, and antecedent soil moisture conditions influence precipitation and hydrologic responses (runoff, recharge, and snowpack) using quantile regression and 2) identify differences in hydrologic response types and magnitudes across the study region. Results indicate that water vapor amount serves as a primary control on precipitation amounts. Holding water vapor constant, precipitation amounts vary with wind direction, depending on location, and are consistently greater at colder temperatures. Runoff efficiencies further covary with temperature and antecedent soil moisture, with precipitation falling as snow and greater available water storage in the soil column mitigating flood impacts of large AR events. This study identifies the coastal and maritime mountain ranges as areas with the greatest potential for hazardous flooding and snowfall impacts. This spatially explicit information can lead to better understanding of the conditions under which ARs of different precipitation amounts are likely to be hazardous at a given location. [ABSTRACT FROM AUTHOR]

Differences between forecasts and observations at eight atmospheric river observatories (AROs) in the western United States during winter 2015/16 are analyzed. NOAA's operational RAP and HRRR 3-h forecasts of wind, integrated water vapor (IWV), integrated water vapor flux (IWV flux), and precipitation from the grid points nearest the AROs were paired with ARO observations presented in the NOAA/Physical Sciences Division's water vapor flux tool (WVFT). The focus of this paper is to characterize and quantify the differences in the WVFT observations and forecasts. We used traditional forecast evaluation methods since they were compatible with the design of the tool: a near-real-time visual depiction of hourly observed and forecasted variables at a single location. Forecast root-mean-squared errors (RMSEs) and unbiased RMSEs, standard deviations of the observed and forecasted variables, and frequency bias scores (FBS) for all of the fields, plus equitable threat scores for precipitation, are presented. Both models forecasted IWV at all AROs and the winds that drive orographic precipitation at most AROs within a reasonable range of the observations as indicated by comparisons of the standard deviations and RMSEs of the forecasts with the standard deviations of the observations and FBS. These results indicated that forecasted advection of moisture to the stations was adequate for generating precipitation. At most stations and most hourly precipitation rates, the HRRR underpredicted precipitation. At several AROs the RAP precipitation forecasts more closely matched the observations at smaller (<1.27 mm h-1) precipitation rates, but underpredicted precipitation rates > 2 mm h-1. [ABSTRACT FROM AUTHOR]

Tornadic thunderstorms rely on the availability of sufficient low-level moisture, but the source regions of that moisture have not been explicitly demarcated. Using the NOAA Air Resources Laboratory HYSPLIT model and a Lagrangian-based diagnostic, moisture attribution was conducted to identify the moisture source regions of tornadic convection. This study reveals a seasonal cycle in the origins and advection patterns of water vapor contributing to winter and spring tornado-producing storms (1981–2017). The Gulf of Mexico is shown to be the predominant source of moisture during both winter and spring, making up more than 50% of all contributions. During winter, substantial moisture contributions for tornadic convection also emanate from the western Caribbean Sea (>19%) and North Atlantic Ocean (>12%). During late spring, land areas (e.g., soil and vegetation) of the contiguous United States (CONUS) play a more influential role (>24%). Moisture attribution was also conducted for nontornadic cases and tornado outbreaks. Findings show that moisture sources of nontornadic events are more proximal to the CONUS than moisture sources of tornado outbreaks. Oceanic influences on the water vapor content of air parcels were also explored to determine if they can increase the likelihood of an air mass attaining moisture that will eventually contribute to severe thunderstorms. Warmer sea surface temperatures were generally found to enhance evaporative fluxes of overlying air parcels. The influence of atmospheric features on synoptic-scale moisture advection was also analyzed; stronger extratropical cyclones and Great Plains low-level jet occurrences lead to increased meridional moisture flux. [ABSTRACT FROM AUTHOR]

A common hypothesis regarding human-induced climate change is that precipitation processes will accelerate leading to an increasing magnitude of rainfall amounts on a daily time scale as the atmosphere warms. This assertion is supported by two physically demonstrable facts, (1) warmer air accommodates more water vapor, and (2) precipitation processes become more efficient as the cloud environment warms. However, by definition, extreme events are rare, and thus statistics of their occurrence and possible long-term changes present difficult challenges, some herein addressed. In any case, the observational datasets on which hypothesis tests may be carried out should cover the longest periods possible because precipitation can naturally vary considerably on even century time scales. In this study we focus on this temporal issue by building long-term daily precipitation datasets for twenty stations, ten along or near the US Pacific Coast (PC) and ten along or near the coast in the US Southeast (SE). Observations for these stations begin between 1840 and 1890 and end in 2018, using the water year (Oct to Sep) to define the annual period. For some metrics, e.g. the annual total precipitation or the number of days per year measuring greater than 25 mm, there is no discernable change over the most recent 145 years (1874–2018). For other metrics, e.g. the magnitude of the wettest day per year or the temporal distribution of the 29 wettest 2-day events in the past 145 years (i.e. nominal 1-in-5-year occurrence), there appears to be an increase in SE and a decrease in PC. Whether these trends are significant for the relatively short climate record of 145 years will be discussed with the conclusion being the limited time frame of analysis does not lead to decisive claims that these changes are outside of the range of natural variability. [ABSTRACT FROM AUTHOR]

At a rough estimate 70% of the Earth's surface is covered by seawater in the form of lakes, rivers, seas or oceans. A study by the United States government concluded that all the water across the Earth would fit into a nearly 1,400-kilometer-long balloon. Water also exists in the air in form of water vapors, in lakes and debris, in polar caps and in glaciers and in living creatures. The quest for understanding what lies below the water bodies has motivated the development of autonomous underwater vehicles (AUVs).Nowadays, the Autonomous Underwater Vehicles (AUV's) have an extensive palette of applications in marine geoscience, and day after day presents an important increase in the scientific, commercial, military, and policy sectors. The ability and the possibility to operate autonomously on board of vessel, makes them very usefully and suitable for exploration of extreme environments, beginning to the deepest small vents and finishing with polar ice sheets. The vehicle helps us to improve our ability to image the seafloor, ensuring a higher resolution of seafloor mapping data that can be obtained from surface vessel. [ABSTRACT FROM AUTHOR]

Redistribution of water by convection is important to the regional and global energy balance, but the characteristics of vertical water transport in convective clouds at different heights are not well understood. In this study, the vertical transport of water in continental isolated convective clouds is investigated using airborne in-situ measurements made in High Plain Cumulus (HiCu) project. The profiles of the mass flux of water vapor and condensed water, and the cloud width and vertical velocity dependency of the relative contribution to the water budget are statistically analyzed. The results show: 1) The probability density functions (PDFs) of the water vapor mass flux were in lognormal distributions and narrowed with height, while the PDFs of the mass flux of condensed water broadened with height from 2 to 8 km. 2) The net flux of vapor decreased significantly with height. Though the flux of condensed water increased with height, the net flux of total water at cloud top was only about 40% of the influx at cloud base. Averagely, about 80% of the observed condensed water at cloud top was in liquid phase. 3) The clouds provided the main contribution to the water vapor flux transit from small-scale at low-levels to medium and large-scale at high-levels. Overall, the clouds in a scale of 1–5 km had the major contribution to the water mass flux. 4) As the clouds developed vertically, stronger drafts accounted for an increasing contribution to the water budget, and most of the upward water transport can be attributed to updraft cores. • vertical transport of water in continental isolated convective clouds is investigated using airborne in-situ measurements. • The flux of vapor decreased with height, while the flux of condensed water increased with height. • As the clouds developed vertically, larger clouds with stronger drafts accounted for an increasing contribution to the water budget. [ABSTRACT FROM AUTHOR]

Unlike the commonly used relative humidity, vapor pressure deficit (VPD) is an absolute measure of the difference between the water vapor content of the air and its saturation value and an accurate metric of the ability of the atmosphere to extract moisture from the land surface. VPD has been shown to be closely related to variability in burned forest areas in the western United States. Here, the climatology, variability, and trends in VPD across the United States are presented. VPD reaches its climatological maximum in summer in the interior southwest United States because of both high temperatures and low vapor pressure under the influence of the northerly, subsiding eastern flank of the Pacific subtropical anticyclone. Maxima of variance of VPD are identified in the Southwest and southern plains in spring and summer and are to a large extent driven by temperature variance, but vapor pressure variance is also important in the Southwest. La Niña-induced circulation anomalies cause subsiding, northerly flow that drives down actual vapor pressure and increases saturation vapor pressure from fall through spring. High spring and summer VPDs can also be caused by reduced precipitation in preceding months, as measured by Bowen ratio anomalies. Case studies of 2002 (the Rodeo-Chediski and Hayman fires, which occurred in Arizona and Colorado, respectively) and 2007 (the Murphy Complex fire, which occurred in Idaho and Nevada) show very high VPDs caused by antecedent surface drying and subsidence warming and drying of the atmosphere. VPD has increased in the southwest United States since 1961, driven by warming and a drop in actual vapor pressure, but has decreased in the northern plains and Midwest, driven by an increase in actual vapor pressure. [ABSTRACT FROM AUTHOR]

The seasonal and diurnal climatologies of precipitable water and water vapor flux in the mid-Atlantic region of the United States are examined. A new method of computing water vapor flux at high temporal resolution in an atmospheric column using global positioning system (GPS) precipitable water, radiosonde data, and velocity-azimuth display (VAD) wind profiles is presented. It is shown that water vapor flux exhibits striking seasonal and diurnal cycles and that the diurnal cycles exhibit rapid transitions over the course of the year. A particularly large change in the diurnal cycle of meridional water vapor flux between spring and summer seasons is found. These features of the water cycle cannot be resolved by twice-a-day radiosonde observations. It is also shown that precipitable water exhibits a pronounced seasonal cycle and a less pronounced diurnal cycle. There are large contrasts in the climatology of water vapor flux between precipitation and nonprecipitation conditions in the mid-Atlantic region. It is hypothesized that the seasonal transition of large-scale flow environments and the change in the degree of differential heating in the mountainous and coastal areas are responsible for the contrasting diurnal cycle between spring and summer seasons. [ABSTRACT FROM AUTHOR]

This study uses an empirical downscaling method based on self-organizing maps (SOMs) to produce high-resolution, downscaled precipitation projections over the state of Pennsylvania in the mid-Atlantic region of the United States for the future period 2046-65. To examine the sensitivity of precipitation change to the water vapor increase brought by global warming, the authors test the following two approaches to downscaling: one uses the specific humidity in the downscaling algorithm and the other does not. Application of the downscaling procedure to the general circulation model (GCM) projections reveals changes in the relative occupancy, but not the fundamental nature, of the simulated synoptic circulation states. Both downscaling approaches predict increases in annual and winter precipitation, consistent in sign with the 'raw' output from the GCMs but considerably smaller in magnitude. For summer precipitation, larger discrepancies are seen between raw and downscaled GCM projections, with a substantial dependence on the downscaling version used (downscaled precipitation changes employing specific humidity are smaller than those without it). Application of downscaling generally reduces the inter-GCM uncertainties, suggesting that some of the spread among models in the raw projected precipitation may result from differences in precipitation parameterization schemes rather than fundamentally different climate responses. Projected changes in the North Atlantic Oscillation (NAO) are found to be significantly related to changes in winter precipitation in the downscaled results, but not for the raw GCM results, suggesting that the downscaling more effectively captures the influence of climate dynamics on projected changes in winter precipitation. [ABSTRACT FROM AUTHOR]

Measurements of water vapor and clouds in the polar regions are difficult, because conventional instruments show little sensitivity (∼1.3 K/mm) to low amounts. On the other hand, millimeter- and submillimeter-wavelength radiometry offers greatly enhanced sensitivity (up to 51.4 K/mm, depending upon frequency). For this reason, the National Oceanic and Atmospheric Administration's Physical Science Division designed a new instrument, the Ground-Based Scanning Radiometer (GSR), for continuous and unattended observations at millimeter and submillimeter wavelengths (50-380 GHz). The GSR was deployed for the first time during the Arctic winter radiometric experiment in March-April 2004. In this paper, we discuss the GSR calibration procedure, which allows for accurate measurements during clear and cloudy skies. Error-budget analysis and comparison with independent measurements show an absolute accuracy on the order of 1-2 K. Examples of multifrequency and multiangle GSR observations are illustrated, representing a valuable new data set for the study of water vapor, clouds, and atmospheric absorption models in the Arctic. [ABSTRACT FROM AUTHOR]

The seasonal extent of the North American Monsoon (NAM) is highly variable and potentially sensitive to future climate change. Our objective was to determine how regional monsoonal patterns influence mountain precipitation near the NAM northwest boundary. Among the data we analyzed, a unique opportunity was provided by hourly observations collected on the Sheep Range (2300 m asl), in the Mojave Desert of southern Nevada, during 2011–2017. Long-term 800-m Parameter-elevation Relationships on Independent Slopes Model (PRISM) precipitation time series showed that the site is representative of mountain areas in the NAM northwest region. Based on in situ observations, we divided the water year into three seasons: cool (1 October through 31 March), early warm (1 April through last day with dewpoint <9.4 °C), and late warm (first day with dewpoint ≥9.4 °C through 30 September). Dewpoint temperature differed by about 8 °C between early warm season (mean of −6.3 °C) and late warm season (mean of 2.3 °C). According to ANCOVA model results, increasing hourly dewpoint associated with afternoon thunderstorms in the late warm season had the greatest relationship with hourly precipitation (F-value = 237.8, p-value < 0.01). Except for 2016, more precipitation fell at our study site during the late than the early warm season. Late warm season precipitation contributed the most (43–56%) to total water-year precipitation during the 2012–2015 extended drought. Southwestern USA regional composites of vertically integrated water vapor transport (IVT) suggested that water vapor in the cool and early warm season originated from the Pacific Ocean to the west, while a transition to a NAM-like pattern of northward IVT coincided with the late warm season. [ABSTRACT FROM AUTHOR]

The water and carbon cycles are fundamentally coupled through transpiration and photosynthesis, as plants inevitably lose water in order to gain carbon. However, isolating transpiration from the "bulk" terrestrial water-flux of evapotranspiration has remained challenging and difficult to scale. Several methods have been proposed to estimate transpiration and canopy conductance, which reflects the canopy-scale regulation of transpiration, but they have generally been applied narrowly or non-systematically. The U.S.-based National Ecological Observatory Network, however, is entering operation and is poised to provide eddy covariance and isotopic measurements of carbon dioxide and water vapor in a consistent manner at a continental scale. When combined, isotopic measurements of carbon dioxide and water vapor and eddy covariance measurements allow for the development of semi-independent, robust, and standardized estimates of ecosystem transpiration and canopy conductance. Here, we provide initial estimates of isotope ratios of carbon and water fluxes and their variability across 20 sites that have available paired isotopic and eddy covariance measurements. Follow-on field work over the next two years will add additional constraints on ecosystem traits and soil water isotope ratios to help refine estimates of transpiration fluxes and relate spatial and temporal variability in transpiration and canopy conductance to plant functional traits. Finally, our estimates of transpiration, its spatiotemporal variability, and its covariance with plant traits will be used to improve representation of transpiration processes in ecological and land-surface models. Refinements to our understanding of continental-scale controls and variation in transpiration gleaned from this project will better inform our projections of ecosystem response and resilience to future environmental conditions. [ABSTRACT FROM AUTHOR]

Precipitation is one of the most important components of the global water and energy cycles,which together regulate the climate system. Future changes in precipitation patternsare likely to bear the largest impacts on society related to climate change. Precisequantifications of precipitation at high spatio-temporal resolution is key for flood anddrought monitoring and forecasting, water resources and agricultural management,large-scale hydrological modeling, weather predictions, and climate studies. Thelaunch of NOAA&#x2019;s latest generation of Geostationary Operational EnvironmentalSatellites (GOES), known as the GOES-R Series, has opened a new window inquantifying precipitation rates, specifically in the Western United States wherethe vantage point of space can complement the degraded weather radar coverageof the NEXRAD network. Apart from its significant advantages of low-latencyand high resolution, GOES-R provides multi-spectral data, which can be exploitedto improve the precipitation retrieval accuracy from space-based geostationaryplatforms. The goal of the present study is to investigate the potential for improving precipitationestimation from algorithms such as SCaMPR (Kuligowski et al. 2016) using multi-spectraldata from the GOES-R satellite. Specific aspects of detection of precipitating cloud regions,classification of cloud types and quantification of precipitation rates are investigated. Alongwith the multi-spectral data, the potential of various additional indices derived from thesedata is also studied. The CPC combined microwave (MWCOMB) dataset (Joyce et al. 2004)is used as a precipitation reference and matched with GOES-R observations over summer2018 across the conterminous United States (CONUS). Results confirm the usefulness ofGOES-R infrared and water vapor absorption bands for precipitation detectionand quantification. Among various channel combinations (e.g. difference betweentwo spectral bands) indices involving water vapor absorption bands show morepotential with respect to combinations of infrared bands for both detection andquantification. Another takeaway from the study is that although GOES-R observations have significantinformation to estimate precipitation, the information content is not sufficient todeterministically detect, classify and quantify precipitation. For example, some precipitationprocesses cannot be captured and retrieved from cloud top information collected fromgeostationary satellite data. The basis for new satellite precipitation approaches focusing onprobabilistic classification and quantification of precipitation is demonstrated (e.g. Grams etal. 2016; Kirstetter et al. 2018). References: Grams, H. M., Kirstetter, P. E., &#x0026; Gourley, J. J. (2016). Naïve Bayesian PrecipitationType Retrieval from Satellite Using a Cloud-Top and Ground-Radar MatchedClimatology. Journal of Hydrometeorology, 17(10), 2649-2665. Joyce, R. J., Janowiak, J. E., Arkin, P. A., &#x0026; Xie, P. (2004). CMORPH: A methodthat produces global precipitation estimates from passive microwave and infrareddata at high spatial and temporal resolution. Journal of Hydrometeorology, 5(3),487-503. Kirstetter, P. E., Karbalaee, N., Hsu, K., &#x0026; Hong, Y. (2018). Probabilistic precipitationrate estimates with space-based infrared sensors. Quarterly Journal of the RoyalMeteorological Society, 144, 191-205. Kuligowski, R. J., Li, Y., Hao, Y., &#x0026; Zhang, Y. (2016). Improvements to thegoes-r rainfall rate algorithm. Journal of Hydrometeorology, 17(6), 1693-1704. [ABSTRACT FROM AUTHOR]

Hurricanes produce devastating economic, social and environmental impacts in the areas they strike. The 2017 Atlantic hurricane season was one of the most active on record, witnessing the third highest number of major hurricanes in a single year of the past century, surpassed only by the 1961 and 2005 seasons. Accurately predicting their path and intensity is therefore extremely valuable. The Global Positioning System (GPS) captures water vapour distributions in the atmosphere within a few millimeters of accuracy under all weather conditions and in real time. We used an integrated water vapour (IWV) retrieved with GPS receiver to track and explore the complex properties of storm events in their spatial and temporal distribution, using a network of ground-based GPS receivers. Our results show that a surge in GPS-retrieved IWV occurred several hours prior to the manifestation of the three major hurricanes to hit the USA's east coast in 2017 and 2018, namely Florence, Harvey and Irma. For our ensemble forecasts, we used the GPS-retrieved IWV data as input to spaghetti lines empirical weather models, enabling us to predict the paths of hurricanes Harvey and Irma. Hence, a directly estimable parameter derived from GPS can provide an additional resource for improving the monitoring of hurricane paths, hitherto not reported. The GPS-retrieved IWV and satellite rainfall products Global Precipitation Measurement Integrated MultisatellitE Retrievals and Tropical Rainfall Measuring Mission (GPM IMERG and TRMM) exhibit a strong coupling associated with the footprint of the hurricanes. A correlation of 65 % between the two parameters was found. [ABSTRACT FROM AUTHOR]