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The provided article presents the conditions and factors that have a direct impact on formation of ice and frost deposits on the overhead catenary wires, and also considers the prediction of the duration of the ice-hazardous period, which is considered in the method for calculating the number of vibrating pantographs, pneumatic drums on rolling stock and devices for mechanical cleaning of ice in contact network areas depending on the zoning of railway sections along the thickness of the ice wall. The possibility of using a classifier model based on a "decision-making tree" in the case of insufficient meteorological observation data is shown. The offered probabilistic model for predicting duration of an icy period makes it possible (with an acceptable error relative to the actual data) to predict the average number of days with formation of ice on the overhead catenary wires considering the several input variables. [ABSTRACT FROM AUTHOR]

Depending on the Multiple Linear Regression Equation and its improvement, the daily maximum air temperature was predicted based on the historical observations of the Baghdad meteorological station for the period between (2005-2020) and for the winter and summer seasons separately, where the mentioned station is an example for regions with a subtropical climate It has hot dry summers and cool rainy winters. The values recorded in the hour 0300 GMT related to minimum air temperature, wind speed and relative humidity were depended on. The associated observations were analyzed for net days using multiple liner regression technique to predict the maximum daily air temperature for any day during winter and summer, It was characterized by a positive relationship for minimum air temperature (0.69,0.62) and a negative relationship for wind speed (-0.62,-0.55) and also a negative relationship for relative humidity (-0.07,-0.55) for both seasons, winter and summer, respectively. A comparison between the expected maximum air temperature and the recorded maximum air temperature was made to improve the work of the equation by analyzing the residuals of the daily forecast, the bias by analyzing the number of relative occurrences of the occurrence of these errors in order to add value (- 0.1℃) for the separation equation winter and the value (0.05℃) for the summer equation as the error adjustment term. [ABSTRACT FROM AUTHOR]

The paper analyzes the maximum discharge, and in some cases, the floods caused by them, observed in the Ijevan section of the Aghstev River Basin during the period of 2010-2020 and an attempt was made to predict the expected floods based on the forecast of a high-resolution digital weather forecast, WRF precipitation, temperature, and other elements. The observation data of the Ijevan hydrological observatory of the Aghstev River were used for the work, and the actual meteorological values were taken from the observations of the Ijevan meteorological station. [ABSTRACT FROM AUTHOR]

Nowadays, Season plays a role in the development of outdoor spaces for pedestrians. This research studies the influence of seasonal variations on pedestrian thermal comfort using meteorology and field observations at selected footpaths around the major tourist areas of Malacca in Malaysia. For the experiment, preselected sunny days, indicating each of the seasons, were chosen. Meteorological transects were hourly from 10:00 am to 17:00 pm. 200 Respondents were questioned to record their thermal awareness, comfort level, and preferences. Besides meteorological information, adaptation, thermal comfort vote and preference, age, season, and hour of the day were significant non-meteorological factors. The findings show that the thermal experience and expectation existed in different seasons and people changed perceptions of the outside thermal environment. Almost 80% local tourist and 55 % international tourist was accepted Physiologically Equivalent Temperature (PET), influenced by the local climate and thermal adaptation. The subjective thermal sensation on PET generated an acceptable ranging from 32.6°C to 36.8°C, based on the seasonal variations. These findings elucidate the optimal design of outdoor spaces for increasing the utilization rate. The seasonal variation must take into account to design outdoor landscape design for different seasons to communicate with the atmosphere and enhance thermal comfort. [ABSTRACT FROM AUTHOR]

In this article is proposed a method for forecasting vehicle traffic intensity in urban conditions and provides an estimate of the forecasting error. For input data in this study are used: the number of vehicles that have passed through a location of the road, based on data collected by observations; meteorological conditions; the day of the week; the season. For this purpose, database processing methods, statistical and stochastic methods are used. [ABSTRACT FROM AUTHOR]

In this proceeding we report initial studies into the big data set acquired by the Cloud Condensation Nuclei (CCN) counter of the Basic Environmental Observatory (BEO) Moussala over the whole 2016 year at a frequency of 1 Hz. First, we attempt to reveal correlations between the results for CCN number concentrations on the timescale of a whole year (2016) as averaged over 12 month periods with the meteorological parameters for the same period and with the same time step. Then, we “zoom” into these data and repeat the study on the timescale of a month for two months from 2016 – January and July, with a day time step. For the same two months we show the CCN size distributions averaged over day periods. Finally, we arrive at our main result – typical, in terms of maximal and minimal number concentrations, CCN size distributions for chosen hours, one hour for each month of the year, hence 24 distributions in total. These data show a steady pattern of peaks and valleys independent of the concrete number concentration which moves up and down the number concentrations (y-axis) without significant shifts along the sizes (x-axis). [ABSTRACT FROM AUTHOR]

On March 11, 2011, the Tohoku-Oki earthquake (Mw 9.0) occurred on the plate interface of the subducting Pacific plate. During the co- and post-seismic periods, almost all GEONET and seafloor observations detected eastward crustal deformation. However, seafloor observations around main raptured zone moved in a westward direction during the post-seismic period. In this study, we estimate the spatio-temporal slip distribution during the co- and post-seismic periods from observed crustal deformations, such as GEONET and seafloor observations. For inversion, we use a viscoelastic Green's function derived from a three-dimensional finite element method considering the underground structure. The estimated maximum co-seismic slip is approximately 60m from the Japan Trench. Off Iwate prefecture, the moment magnitude and maximum afterslip 2.5 years after the Tohoku-Oki earthquake are approximately 8.13 and 2.0m, respectively. The afterslip distributions differ from the co-seismic slip distribution, and the relationship between the co-seismic and afterslip regions is complementary. [ABSTRACT FROM AUTHOR]

The FORMOSAT-3 / COSMIC satellite with GPSRO technique was performed to detect an earthquake in the presence of fluctuations in the ionosphere layer. This research was used to know the change of TEC in ionosphere layer during earthquake. FORMOSAT-3 / COSMIC was a microsatellite that aims for weather and climate assessment, and atmospheric, ionospheric and geodesy observations. FORMOSAT-3 / COSMIC was a Taiwan-USA collaboration by launching 6 microsatelt on LEO (Low Earth Orbit). Each of these FORMOSAT-3 / COSMIC satellites has a payload: GPS Occultation Experiment (GOX), Tiny Ionospheric Photometer (TIP) and Tri-band Beacon (TBB). GOX consists of a GPS receiver, the highest rated occultation antenna and Precise Orbit Determination (POD) antenna to collect data from Radio Occultation (RO) observations and precision orbits. RO is obtained from GPS orbit and different FORMOSAT-3 / COSMIC (LEO) orbit causing fluctuation when transmitting signal. This variation contains ion component called Total Electron Content (TEC). The earthquake of March 2nd, 2016 west Sumatra was a strike slip earthquake which had magnitude 7.7 Mw with tsunami potential. In this earthquake detected an ionospheric disturbance of 3.5 TECU after the earthquake. [ABSTRACT FROM AUTHOR]

The objective of this research is to estimate Probable Maximum Precipitation (PMP) using satellite data, as one of the solutions to the lack of observation data, and to know the representativeness of satellite data used. The Tropical Rainfall Measuring Mission (TRMM) incredibly defined the spatial variation of PMP. The north area of Subang Regency has the highest PMP value compared to the surrounding areas for duration of 3, 6, 9, 12, 18 and 24 hours. This phenomenon is due to the control of topography against extreme conditions. The PMP itself is generally used to determine the Probable Maximum Flood (PMF) value. The PMP-PMF concept can be utilized for flood management, the determination of temporary retention areas and spillways design reference on dams. [ABSTRACT FROM AUTHOR]

On 28 February and 9 March 2017, there has been flooding in different areas of the Bandung Basin. Flood on 28 February 2017 occurred in the southern part of Bandung Basin, while flood on 9 March 2017 only occurred in the northern part of Bandung Basin. The floods were caused by heavy rainfall in each region. Allegedly the rain that occurred in the region is a localized rain. Localized rain means rain only occurs in one area whereas other areas do not rain. In this study, an analysis of the localized rain is based on observational data grid and convective cloud distribution that produces rain. The data grid is based on Automatic Weather Station (AWS) network data located in the Bandung Basin. Ordinary kriging is an interpolation method chosen to create a data grid and produce grid data with a spatial resolution of 0.025 ° × 0.025 ° and its temporal resolution of 10 minutes with available data that is from January to March 2017. Spread of rain in the Bandung Basin can be seen clearly using grid of observational data that have been made and found the existence of localized rain events in this region. Results from the grid of rain data indicate if the rain on 28 February 2017 occurred at different times between the northern and southern part of Bandung Basin. The rain began to occur first in the northern part of Bandung at 12:10 local time (LT). Further rain recorded at Dayeuhkolot station located in the middle of the Bandung Basin at 14:00 LT. While in the southern part of Bandung basin, the rain started measuring at 16.00 LT. Rain in the Bandung Basin on 28 February 2017 is not only produced by a single convective cloud that moves, but there are three convective clouds that produce rain in the Bandung Basin. A convective cloud originated from the Bandung Basin itself and two other convective clouds originated from areas outside the Bandung Basin. Wide rain coverage is the result of the merger of the three convective clouds. While the rain that occurred on 9 March 2017 only occurred in the northern part of Bandung. The rain began measuring in Lembang and Dagopakar at 17:10 LT. Rain is generated by convective clouds that grow outside the northern part of Bandung Basin to enter the Bandung Basin. By knowing the area of rain distribution, can also know which region gets the highest rain intensity. It is important to know the extent of the distribution of rain, especially for areas that have flood risk as a form of disaster mitigation so as to reduce the losses incurred. [ABSTRACT FROM AUTHOR]

On 29 December 2013, several areas of Sumatra Island, particularly Padang City, were flooded by heavy rains lasting from 28 December 2013. The torrential rains coincided with the emergence of a synoptic-scale phenomenon in the eastern Indian Ocean known as Double Vortex. However, it is still unclear whether those phenomena interrelated one to another, thus a deep examination is needed to study the relationship between the torrential rains and the Double Vortex. In this study, the identification of the Double Vortex phenomena was carried out using daily wind reanalysis data from the National Centers for Atmospheric Prediction and National Center for Atmospheric Research (NCEP-NCAR) during 2005/2006 to 2015/2016. Furthermore, the effect of Double Vortex on the intensity of rainfall is analyzed quantitatively using surface observation data in 16 stations spread across the western Indonesia, especially Sumatra, Java and Borneo Island. Double Vortex identification results showed 56 Double Vortex occurred during the study period. Furthermore, the analysis of surface observation data indicates a significant increase in rainfall during Double Vortex, especially in Padang, Bengkulu and Palembang stations with an increase of 12.8, 8.5 and 12.2 mm/day, respectively. Significant increase of rainfall is expected due to the location of the three stations situated between two vortexes. On the other hand, there is a significant decrease in rainfall in Java after the Double Vortex event due to the weakening of cross equatorial flow as a result of the vortex in the eastern Indian Ocean north of the equator where the Double Vortex phenomena occurred. It is important to monitor the Double Vortex event as part of hazard mitigation due to the capability of the event to bring damage as has been pointed out. [ABSTRACT FROM AUTHOR]

Lack of observation network in the vicinity of oceanic intraplate earthquake lead the estimation of coseismic fault slip with high uncertainty. Satriano et al. [2] and Wei et al. [3] found NNE trending left-lateral slip as the primary features. In another hand, Yue et al. [4] and Hill et al. [5] proposed WNW trending right-lateral faults structure as the main characteristic. Here, we investigate the coseismic fault model that could explain the coseismic offset both vertical and horizontal in a 3-D heterogeneous earth structure. We constructed finite element model that include threedimensional velocity structure, topography/bathymetry, spherical-earth and subducting slab. In this study, we employed scaling slip to adjust slip amount and total seismic moment. Instead of original slip amount, we preserve seismic moment as a basis comparison. Based on vertical and horizontal observation data, WNW trending right-lateral fault could fit better than NNE trending left-lateral fault. The present study demonstrates best-fit calculation using scaling slip optimized to the horizontal or vertical observation lead the both fault model worsen the misfit of vertical or horizontal component, respectively. This result analysis indicates a trade-off between vertical and horizontal component and reflects the importance of revisiting the fault slip modeling incorporating vertical and horizontal data equally. [ABSTRACT FROM AUTHOR]

This research has been conducted the Jatibarang Dam deformation measurement in 2017. The 2016 GNSS measurement data and 2017 measurement results processed by two methods. The two methods are referencing the deformation observation points to 1) the global reference stations (IGS station), 2) to the local reference stations (CORS BIG). The velocity rate of a horizontal component of observation station of the Jatibarang Dam deformation on method 1 about 16.7 mm/year to 36.2 mm/year. While in method 2 ranges 1.7 mm/year to 9.0 mm/year. The velocity rate at method one may still be affected by deformation due to the rotation of the Sunda block. The velocity rate of a horizontal component of observation station of the Jatibarang Dam deformation on method 1 after eliminating the effect of Sunda Block Rotation become ranged from 2.9 mm/year to 13.2 mm/year. The statistical test results that all of the observation stations of Jatibarang Dam by method 1 and 2 have no movement or no deformation. [ABSTRACT FROM AUTHOR]

Internet of Things (IoT) is an interconnection of various devices for collecting and exchanging data over network. Application of IoT includes many domains such as environmental monitoring, smart home, smart energy monitoring, healthcare, agriculture and smart transportation. In this paper, we propose a design of meteorological monitoring and environmental gamma radiation monitoring system for early detection of radioactive material in the environment. The study consists of system architecture, development of Arduino-based gamma radiation monitoring device, data transfer with MQTT protocol, storage of monitoring data to database, and development of user interface (UI) for data presentation. The prototype of the system has been developed and tested around the Center for Nuclear Facilities Engineering at Serpong Nuclear Complex. The presence of radioactive material was simulated using check source which emitted low dose rate gamma. The results were analyzed and presented, while meteorological data was compared with the monitoring result from the existing meteorological monitoring system. The results showed that the proposed system is able to detect the presence of gamma radiation source and meet the design requirement. [ABSTRACT FROM AUTHOR]

This article was based on the climate data of 125 meteorological stations from 1982 to 2011 in Yunnan Province, the daily basis ET0 was calculated with Penman-Monteith equation recommended by FAO in 1998. Then the Kriging interpolation method and related methods of climate statistical diagnosis analysis were used to analyze the features. The main results showed that the highest value of annual ET0 of Yunnan Province was the joint parts of Dali, Lijiang and Chuxiong, and also the north of Chuxiong and Kunming, while the least value was the northeast and northwest of Yunnan Province. The ET0 was showed rising trend, the speed was about 5.9mm/10a, but the rising trend was not significant. The ET0 of spring was highest, and the ET0 of summer and autumn was taken the second place, the ET0 of winter was last. The ET0 of spring, summer, autumn, winter was account for 33.35 per cent, 28.91 per cent, 20.36, per cent, 17.39 per cent of annual ET0 respectively. The ET0 of May was highest and December was least in annual. ET0 was closely related to wind speed, relative humidity, hours of sunshine and the daily maximum temperature. The correlation between wind speed, hours of sunshine, the daily maximum temperature and ET0 was very significantly positive, while the correlation between relative humidity and ET0 was very significantly negative. [ABSTRACT FROM AUTHOR]

The main goal of this investigation is to develop a kind of "urban reanalysis" - the database of meteorological and radiation fields under Moscow megalopolis with high spatial resolution. Sky View Factor (SVF) is widely used for evaluating the solar irradiance attenuation in urban canopy. In this study we suggested raster-based calculation of SVF. We applied this technique for evaluating specific features in UV irradiance at Moscow megalopolis conditions. We showed that relative frequency of SVF over the territory of Moscow higher than 80% is observed in more than 86% of cases. The maps of UV losses due to sky obscuring over the territory of Moscow have been obtained for different seasons. [ABSTRACT FROM AUTHOR]

In previous studies1,2 we derived new estimates for the magnitude of the components of the global mean energy budget using to the extent possible the information contained in direct observations from surface and space. Here we establish complementary estimates for the global mean energy budget specifically under cloud-free conditions. The energy fluxes under cloud-free conditions at the Top of Atmosphere (TOA) can be determined with high accuracy from satellite measurements (CERES-EBAF). For the estimation of their counterparts at the Earth's surface we follow the approach presented in our recent studies, based on an analysis of 39 state of the art global climate models from CMIP5 and their bias structure compared to a comprehensive set of high quality surface observations from the Baseline Surface Radiation Network (BSRN). Thereby we infer a best estimate of 249 Wm-2 for the global mean clear-sky downward shortwave radiation at the surface, and a corresponding clear-sky surface shortwave absorption of 216 Wm-2, considering a global mean surface albedo of 13 %. Combined with a best estimate for the global mean net shortwave influx at the TOA under cloud-free skies from CERES-EBAF of 287 Wm-2, this leaves an amount of 71 Wm-2 absorbed shortwave radiation in the cloud-free atmosphere. The 71 Wm-2 coincide with our earlier estimate for this quantity in Wild et al. (2006)3 based on older models and fewer direct observations, suggesting that this estimate is fairly robust. For the clear-sky downward longwave radiation at the Earth surface we obtain a best estimate of 314 Wm-2. A comparison of the clear-sky global energy balance diagram presented here with the corresponding all-sky diagram established in our previous studies enables a quantification of the global mean shortwave, longwave and net cloud-radiative effects at the TOA, within the atmosphere and at the surface, as well as an assessment of their representation in climate models. [ABSTRACT FROM AUTHOR]

Observations of rainfall data are always changing over time. With the concern over climate change, this study is done to demonstrate how Generalized Additive Models (GAMs) could be utilized to model daily rainfall amount over Johor area. Hence, in modeling rainfall amount, Cyclic Cubic Spline is used as the smoothing technique. This research concentrated on the daily rainfall series with the duration period of 1980 to 2011 from six rainfall stations in Johor area. The results indicated that the rainfall stations demonstrate different behaviours of rainfall patterns. Based on the resulting curves with fitted smoothing parameters, a summary of statistics of the six stations were obtained. The results from the model will then be used to compare the rainfall patterns among the stations. [ABSTRACT FROM AUTHOR]

In this study; we examined one dimensional crustal velocity structure of Izmir gulf and surroundings. We used nearly one thousand high quality (A and B class) earthquake data which recorded by Disaster and Emergency Management Presidency (AFAD) [1], Bogazici University (BU-KOERI) [2] and National Observatory of Athens (NOA) [3,4]. We tried several synthetic tests to understand power of new velocity structure, and examined phase residuals, RMS values and shifting tests. After evaluating these tests; we decided one dimensional velocity structure and minimum 1-D P wave velocities, hypocentral parameter and earthquake locations from VELEST algorithm. Distribution of earthquakes was visibly improved by using new minimum velocity structure. [ABSTRACT FROM AUTHOR]

We investigated earthquake hazard parameters for Eastern part of Turkey by determining the a and b parameters in a Gutenberg-Richter magnitude-frequency relationship. For this purpose, study area is divided into seven different source zones based on their tectonic and seismotectonic regimes. The database used in this work was taken from different sources and catalogues such as TURKNET, International Seismological Centre (ISC), Incorporated Research Institutions for Seismology (IRIS) and The Scientific and Technological Research Council of Turkey (TUBITAK) for instrumental period. We calculated the a value, b value, which is the slope of the frequency-magnitude Gutenberg-Richter relationship, from the maximum likelihood method (ML). Also, we estimated the mean return periods, the most probable maximum magnitude in the time period of t-years and the probability for an earthquake occurrence for an earthquake magnitude ≥ M during a time span of t-years. We used Zmap software to calculate these parameters. The lowest b value was calculated in Region 1 covered Cobandede Fault Zone. We obtain the highest a value in Region 2 covered Kagizman Fault Zone. This conclusion is strongly supported from the probability value, which shows the largest value (87%) for an earthquake with magnitude greater than or equal to 6.0. The mean return period for such a magnitude is the lowest in this region (49-years). The most probable magnitude in the next 100 years was calculated and we determined the highest value around Cobandede Fault Zone. According to these parameters, Region 1 covered the Cobandede Fault Zone and is the most dangerous area around the Eastern part of Turkey. [ABSTRACT FROM AUTHOR]

North Anatolian Fault (NAF) is one from the most important strike-slip fault zones in the world and located among regions in the highest seismic activity. The NAFZ observed very large earthquakes from the past to present. The aim of this study; the important parameters of Gutenberg-Richter relationship (a and b values) estimated and this parameters taking into account, earthquakes were examined in the between years 1900-2015 for 10 different seismic source regions in the NAFZ. After that estimated occurrence probabilities and return periods of occurring earthquakes in fault zone in the next years, and is being assessed with Poisson method the earthquake hazard of the NAFZ. The Region 2 were observed the largest earthquakes for the only historical period and hasn't been observed large earthquake for the instrumental period in this region. Two historical earthquakes (1766, MS=7.3 and 1897, MS=7.0) are included for Region 2 (Marmara Region) where a large earthquake is expected in the next years. The 10 different seismic source regions are determined the relationships between the cumulative number-magnitude which estimated a and b parameters with the equation of LogN=a-bM in the Gutenberg-Richter. A homogenous earthquake catalog for MS magnitude which is equal or larger than 4.0 is used for the time period between 1900 and 2015. The database of catalog used in the study has been created from International Seismological Center (ISC) and Bogazici University Kandilli observation and earthquake research institute (KOERI). The earthquake data were obtained until from 1900 to 1974 from KOERI and ISC until from 1974 to 2015 from KOERI. The probabilities of the earthquake occurring are estimated for the next 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 years in the 10 different seismic source regions. The highest earthquake occur probabilities in 10 different seismic source regions in the next years estimated that the region Tokat-Erzincan (Region 9) %99 with an earthquake occur probability for magnitude 6.5 which the return period 24.7 year, %92 with an earthquake occur probability for magnitude 7 which the return period 39.1 year, %80 with an earthquake occur probability for magnitude 7.5 which the return period 62.1 year, %64 with an earthquake occur probability for magnitude 8 which the return period 98.5 year. For the Marmara Region (Region 2) in the next 100 year estimated that %89 with an earthquake occur probability for magnitude 6 which the return period 44.9 year, %45 with an earthquake occur probability for magnitude 6.5 which the return period 87 year, %45 with an earthquake occur probability for magnitude 7 which the return period 168.6 year. [ABSTRACT FROM AUTHOR]

The lack of snowfall observations makes snow return period estimation a relevant issue in areas characterized by the absence of snow gauges. Therefore, in these regions, the post-event effects regarding electrical, hydraulic, and road infrastructures become difficult to evaluate. The issue of the estimation for the return period of snow events is solved by analysing pairs of rainfall and temperature data. First, the statistical dependence of the three variables (i.e. snow, rainfall and temperature) is analysed. Second, the return period of a selected rainfall sample, with values conditioned to a specific range of temperatures, is evaluated (i.e., indirect snow return period). Then, the corresponding snow return period (i.e., direct snow return period) is estimated. Finally, the equivalence of both return periods is investigated. The results obtained with the two approaches are compared, presenting encouraging perspectives in terms of return period value equivalence. [ABSTRACT FROM AUTHOR]

The cirrus clouds play an important role in the radiation budget of the earth's atmospheric system and are important to characterize their vertical structure and optical properties. LIDAR measurements are obtained from the tropical station Gadanki (13.5°N, 79.2 °E), India, and meteorological indicators derived from Radiosonde data. Most of the cirrus clouds are observed near to the tropopause, which substantiates the strength of the tropical convective processes. The height and temperature dependencies of cloud height, optical depth, and depolarization ratio were investigated. Cirrus observations made using CALIPSO satellite are compared with lidar data for systematic statistical study of cirrus climatology. [ABSTRACT FROM AUTHOR]

Observations of rainfall data are always changing over time. With the concern over climate change, this study is done to demonstrate how Generalized Linear Models (GLMs) could be utilized to model daily rainfall amount over Johor area. Hence, in modeling rainfall amount, Fourier series are used as the smoothing technique. This research concentrated on the daily rainfall series with the duration period of 1980 to 2011 from six rainfall stations in Johor area. The results indicated that the rainfall stations demonstrate different behaviours of rainfall patterns. Both stations that are located at the eastern area of Johor which is Mersing and Hospital Kota Tinggi are best described with four and three harmonics, while one harmonic is sufficient to model the mean rainfall per rainy day at the stations that are located at the west of Johor. Based on the resulting curves with fitted smoothing parameters, a good summary of statistics of the six stations were obtained. The results from the model will then be used to compare the rainfall patterns among the stations. [ABSTRACT FROM AUTHOR]

The observational climate record is a cornerstone of our scientific understanding of climate changes and their potential causes. Existing observing networks have been designed largely in support of operational weather forecasting and continue to be run in this mode. Coverage and timeliness are often higher priorities than absolute traceability and accuracy. Changes in instrumentation used in the observing system, as well as in operating procedures, are frequent, rarely adequately documented and their impacts poorly quantified. For monitoring changes in upper-air climate, which is achieved through in-situ soundings and more recently satellites and ground-based remote sensing, the net result has been trend uncertainties as large as, or larger than, the expected emergent signals of climate change. This is more than simply academic with the tropospheric temperature trends issue having been the subject of intense debate, two international assessment reports and several US congressional hearings. For more than a decade the international climate science community has been calling for the instigation of a network of reference quality measurements to reduce uncertainty in our climate monitoring capabilities. This paper provides a brief history of GRUAN developments to date and outlines future plans. Such reference networks can only be achieved and maintained with strong continuing input from the global metrological community. [ABSTRACT FROM AUTHOR]

Particle size distribution measurements from 7 nm to 850 nm are being conducted in Western Saudi Arabia utilizing a Differential Mobility Particle Sizer (DMPS). The early results show that the particle size distribution is highly variable, with signatures from the nucleation, Aitken, and accumulation mode. The accumulation mode dominates from midnight to early morning, after which an elevated Aitken mode appears, denoting to local morning activities. New particle formation begins regularly around 10 am, elevating first the nucleation mode concentrations and then the Aitken mode. During evening hours, the nucleation-and Aitken mode concentrations decrease, and the accumulation mode becomes dominant again. The average particle number concentration from December 2012 was 1640 [sharp/mesh/hash_synonym]/cm3. The maximum particle concentration in the region is originated from new particle formation, with a maximum 1h-average of 11400 [sharp/mesh/hash_synonym]/cm3. [ABSTRACT FROM AUTHOR]

Atmospheric aerosol measurements conducted at Environment Canada's observation sites at Alert, Nunavut and the peak of Whistler Mountain, British Columbia are compared with simulations from the global chemical transport model GEOS-Chem with the two-moment bin aerosol microphysics module TOMAS and with the Canadian Atmospheric Global Climate Model (CanAM4). The year-long comparisons show generally good agreement in terms of volume and mass concentrations. The carbonaceous aerosol is underestimated by GEOS-Chem-TOMAS (previously noted by others) and the size distributions, while similar, indicate larger particles and lower number concentrations. The lower numbers and larger particles predicted by GEOS-Chem-TOMAS may be connected with the underestimated carbonaceous aerosol. [ABSTRACT FROM AUTHOR]

In the CLOUD experiment at CERN we have been investigating the chemical species that are most important to atmospheric new particle formation. Sulphuric acid plays a key role in aerosol nucleation, but other vapours and ions can strongly enhance the formation rate. Quantifying the contribution of each species and the conditions under which each one is important is a major challenge and requires sophisticated laboratory experiments. The CLOUD chamber, a 3m stainless steel aerosol chamber exposed to a pion beam from the CERN Proton Synchrotron, can create a precisely controlled atmospheric environment over a wide range of temperatures, ionisation states and gas mixtures, while keeping contamination levels extremely low. CLOUD has studied a range of vapour species at atmospheric concentrations, including, in various combinations, sulphuric acid, ammonia, dimethylamine and alpha-pinene. The effect of ions on the nucleation rates has been measured for all species since it is of considerable interest as a possible link between galactic cosmic rays and climate[1]. This work will present an overview of the nucleation rates measured in CLOUD and compare them with atmospheric observations. [ABSTRACT FROM AUTHOR]

Impacts of African dust particles on mixed-phase and warm stratiform clouds are investigated using four years of collocated CALIPSO and CloudSat measurements. The results show that dust could enhance ice particle concentrations in stratiform mixed-phase clouds by a factor of 2 to 6 at temperatures colder than -12°C. Obvious drizzle suppression in dusty warm stratiform clouds is also observed. The study suggests that the presence of African dust affect both mixed-phase and warm cloud microphysical properties and processes. [ABSTRACT FROM AUTHOR]

We use aircraft observations from two measurement campaigns (SOLAS 2003 and NARE 1993) to investigate the relationships among aerosol, cloud droplets and drizzle in marine stratiform clouds. CCN-sized aerosol number concentration is highly correlated with the cloud droplet number concentration (CDNC). Increases in the number of drizzle-size drops (>100μm) are associated with the liquid water path (LWP) and the CDNC. We derive a function relating the drizzle drop number concentrations to the LWP and CDNC that is compared with that derived from large-eddy simulations using the Khairoutdinov and Kogan[1] parametrization. [ABSTRACT FROM AUTHOR]

The formation, nucleation and impacts of the secondary aerosols of SO4, NO3 and NH4 originated from pollution gaseous precursors of SO2, NOx and NH3 in foggy weather events of Northern China are investigated by field observations and numerical simulation by WRF/Chem model coupled with anthropogenic emission inventory. Results show that the secondary aerosols of SO4, NO3 and NH4 had important impacts on the formation processes and microphysical structure of the foggy event. The concentrations of NOx and NO3 were found to be extremely high in these cases. The concentration of interstitial aerosol NO3 was much higher than SO4 and NH4, but the concentration of SO4 was highest in cloud-borne aerosols. The averaged nucleation activation ratios for SO4, NO3 and NH4 could be as high as 30%, and the maximum ratios could reach over 80% during the fog episode The polluted atmospheric boundary condition can create a favorable condition for fog formation, and increase the fog area by 50% and 5 times in intensity, and extend duration over 1.5h. [ABSTRACT FROM AUTHOR]

In this work satellite based observations were used to estimate the concentration of nucleation mode aerosols over South Africa. The nucleation mode aerosols can not be detected directly with satellite instruments since they are much smaller than the optically active aerosols, hence the concentrations were estimated using proxies introduced by Kulmala et al. (2011). Results showed enhanced values of both primary and regional scale nucleation proxies over the Mpumalanga Highveld industrial area, whereas over the Johannesburg-Pretoria megacity only the primary nucleation proxy showed elevated values. To estimate how well satellite based proxies work, the relation between satellite and in situ based quantities was studied in more detail. The correlation between aerosol optical depth (AOD) and condensation sink (CS) was 0.2-0.3 depending on the location. Boundary layer height affected the correlation somewhat, but there are other factors, such as the effect of dust on AOD, that are more likely to have a stronger impact. [ABSTRACT FROM AUTHOR]

In this study, the grid system of the complex refractive index in the 1.6-μm (SW3) channel of the Global Change Observation Mission (GCOM-C)/Second Generation Global Imager (SGLI) satellite sensor is investigated. This grid system is separated into twelve patterns according to the step size of the real and imaginary parts of the refractive index. Specifically, the Light Scattering solver Applicable to particles of arbitrary Shape (LISAS)/Geometrical-Optics Approximation (GOA) technique is used to simulate the scattering of light by randomly oriented large hexagonal ice crystals. The difference of radiance with refractive index step size is calculated from developed light scattering database using the radiative transfer (R-STAR) solver. The results indicated that the step size of the real part is a significant factor in the difference of radiance. [ABSTRACT FROM AUTHOR]

The data on the radiation balance of an underlying surface, its components, and main factors defining their variations were systematized and generalized for a period of over 50 years (1958-2011) from continuous observations acquired at the Meteorological Observatory of the Moscow State University (MO MSU). The climatic norms of radiation balance were obtained and its variability (diurnal, annual, and interannual) limits were estimated. The tendency to increase in the absorbed, effective, and atmospheric back radiation and terrestrial radiation balance is mostly pronounced in the nighttime in winter months. [ABSTRACT FROM AUTHOR]

Five years (2007-2011) of aerosol optical depth and radiation measurements in Valencia (Spain) have been analysed in order to study empirically the radiative perturbation produced by the dust events to shortwave and longwave spectral ranges at the Earth surface. The direct method has been applied to only cloud free observations. The aerosol produces a surface cooling by -173 and -142 W/m2 per unit optical depth at solar zenith angles of 20° and 50°, respectively, in the shortwave range. The shortwave cooling is partially off-set by 30-40% by the LW heating. The LW effect can be larger (up to 60%) on a daily basis since it acts continuously also during night-time. [ABSTRACT FROM AUTHOR]

The annual cycle of precipitable water vapor is inferred from the MODIS thermal infrared (IR) and nearinfrared (NIR) satellite products under clear-sky conditions and for the period 2002-2008 at 18 sites of the Iberian Peninsula, with the aim to evaluate the capabilities of both algorithms. The paper presents these results in relation with ground observations using different techniques (GPS, sunphotometer, radiosounding), with a special emphasis on GPS. The differences in the monthly means mostly correspond to underestimations, ranging between a few percent to 40%, being generally larger in winter than in summer. For most sites, NIR performs better than IR, and more particularly during the winter. NIR usually presents overestimations in summer that can reach up to 30%. The time-coincident comparison shows that best MODIS/GPS agreement is found for the continental region (rms∼0.3) for both methods, whereas the largest biases and rms differences are found at the Mediterranean sites. [ABSTRACT FROM AUTHOR]

An NSFC (National natural Science Foundation of China) funded research facility aims to deepen our understanding about the interactions within neutral atmosphere layers, i.e., Planetary Boundary layer (PBL), Upper Troposphere-Lower Stratosphere (UT-LS), stratosphere, Mesopause and Lower Thermosphere (MLT), as well as the response of atmospheric processes to solar activities from the top, and the natural and anthropogenic influences from the Earth surface. [ABSTRACT FROM AUTHOR]

Advanced capability for sounding the atmospheric state and for quantifying climate trends using IR spectrometers has made enormous strides in recent years. While substantial societal benefits have accrued from research and operational advanced sounders in polar orbit, many of the expected benefits from this new capability are being squandered. As presented in our 1RS Union talk, capabilities for (1) advanced geostationary sounding for substantially improving severe weather warnings, (2) ground-based networks for continuous boundary layer monitoring, and (3) technological advances for acquiring high information content climate benchmark observations and for inter-calibrating other IR spacecraft instruments have not been realized (two have been delayed indefinitely). Fortunately, there are viable options for moving forward, which we identify in this review. [ABSTRACT FROM AUTHOR]

The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) deployed on board different research aircraft provides detailed pictures of the Upper Troposphere/Lower Stratosphere (UTLS) region. GLORIA uses a two-dimensional detector array for infrared limb observations. GLORIA's in-flight calibration sources are two identical large-area high-precision blackbodies, which are independently controlled at two different temperatures. Thermo-Electric Coolers (TECs) are used to control the temperature of the calibration sources. The calibration sources have been comprehensively characterized for their spatially and spectrally resolved radiation properties in terms of radiation temperature traceable to the International Temperature Scale (ITS-90) at the Physikalisch-Technische Bundesanstalt (PTB), the national metrology institute of Germany. [ABSTRACT FROM AUTHOR]

DWD/Meteorological Observatory Lindenberg is operating a small-scale ground-based network of measurement sites for precipitation and shortwave radiation. The area is located roughly 60 km southeast of Berlin city. 8 measurement sites are equipped with high quality instruments CM21/CM11 by Kipp & Zonen. The quality assessment routinely applied takes into account the basic astronomical and empirical considerations as well as some interdependencies like total to diffuse flux ratio and cross checking with sunshine duration. Possible shading due to growing vegetation is taken into account, too. This is complemented by an approach that is utilizing time-series of clear sky radiative transfer simulations for every site. For that purpose a link to cloud coverage obtained from Meteosat second generation geostationary satellite data, highly resolved in time and space, was established. The paper provides an overview of the surface radiation network and the current activities to improve automatic quality assessment using remotely sensed data and clear sky modelling. First evaluation efforts cover up to 12 years of data. [ABSTRACT FROM AUTHOR]

The outgoing longwave radiation (OLR) at the top of the atmosphere is one of the three components that comprise earth radiation budget. It has also been used very effectively in climate diagnostics/monitoring and fidelity assessment for numerical models because of its sensitivity to atmospheric and earth surface variations. A continuous OLR climate data record of more than three decades with global coverage has been derived using the radiance observations from the High-resolution Infrared Radiation Sounder (HIRS) onboard the NOAA TIROS-N series and the Eumetsat MetOp-A satellites. Past validations of the HIRS OLR data against the broadband-based OLR products derived from ERBE and CERES scanners/non-scanners observations were shown to have very consistent agreement in terms of accuracy, variability, and stability. The HIRS OLR climate data record is now an operational product that is being managed and maintained by the NOAA National Climate Data Center (NCDC) and the Cooperative Institute of Climate and Satellites (CICS)/University of Maryland College Park, respectively. The continuing efforts in validation and intercomparison are the core tasks for the quality control and quality assurance purposes. In this paper, we report the status of the HIRS OLR CDR production, address some known issues, and present the latest validation results based on the CERES Edition 2.6 product release. [ABSTRACT FROM AUTHOR]

In the present study we investigate the effect of contrails on global shortwave radiation. This investigation is performed using continuous hemispherical fish eye photographs of the sky, diffuse and direct shortwave measurements. These measurements have been performed at the solar observatory Kanzelhöhe (1540 m.a.s.l) located in the southern part of Austria during a period of one and half year. The time resolution of the measurements is one minute, which allows to accurately follow the formation-eventually the disappearance or the movement - of the contrails in the sky. Using the fish eye photographs we identified clear sky days with a high contrail persistence. We especially look at situations where the contrails were obstructing the sun. First results show that contrails moving between sun and observer/sensor may reduce the global radiation by up to 68%. In general we however observe that during days with a high contrail persistence the diffuse irradiance is slightly increased. Finally a statistic of the contrail persistence during the period of measurement is presented. In addition the maximum and mean reduction in global irradiance are shown as a function of sun obstruction duration by contrails. [ABSTRACT FROM AUTHOR]

The classification of precipitating cloud systems over Thailand was attempted by using cloud radar reflectivity data separated into convective and stratiform clouds based on a reflectivity threshold. A statistical technique is applied to examining the development of small-scale variability of radar reflectivity over the mesoscale storm. The convective cloud generally brings about higher rain rate than the stratiform cloud. After applying the classification method, rainfall estimation by radar was improved by using specific parameters for each rain type. Moreover, the classified results show consistency with TRMM 2A25 product. [ABSTRACT FROM AUTHOR]

During the last two NASA GPM Ground Validation field campaigns i.e. MC3E and GCPEx in USA and Canada correspondingly, the microwave radiometer ADMIRARI has been operating nearby two dual-frequency radars: the Ka/W band SACR from DOE ARM and the NASA's Ku/Ka band D3R. In addition, observations have currently been performed at the CSU CHILL National Radar Facility with the D3R Ku/Ka band radar synchronized with ADMIRARI for dedicated precipitation events. The present work put into consideration the first results from the aforementioned field campaigns with as a first attempt to combine these multi-sensor, multi-frequency, dual-polarized measurements in a common retrieval approach; limitations and pitfalls will be critically discussed as well. [ABSTRACT FROM AUTHOR]

Based on the ground-based high-resolution infrared radiances observed by the Atmospheric Emitted Radiance Interferometer (AERI), a new method is proposed to identify the clear sky. Meanwhile, we also develop the new algorithms for retrieving the zenith equivalent cloud base height (CBHe) and the equivalent emissivity ([variant_greek_epsilon]e), respectively. The retrieval results in Shouxian indicate that the differences between the CBHe and observational cloud base height (CBH) are much smaller for thick low cloud, and increase with the increasing CBH. The average [variant_greek_epsilon]e for the low, middle, and high cloud is 0.967, 0.781, and 0.616 for the 50 cases, respectively. It decreases with the increasing CBH. The new methods will be useful for studying the role of cloud in the radiation budget in the window region and cloud parameterizations in the climate model. [ABSTRACT FROM AUTHOR]

An Annular Solar Eclipse (ASE) occurred on 15 January 2010, which was observed in most parts of India. This paper reports the changes observed in solar irradiance and meteorological parameters (temp [T], relative humidity [RH] and dew point) associated with the ASE mainly at three locations (Greater Noida, Kanpur and Hyderabad) in India that are located far away from the eclipse path. A decrease in solar irradiance in the range of 25-59% (maximum in Hyderabad and minimum in Greater Noida) as well as a slight decrease in RH is observed during solar eclipse. The radiosonde and AIRS data show changes in the normal trend of meteorological conditions at different pressure levels indicating strong influence of solar eclipse. [ABSTRACT FROM AUTHOR]

Regular ground-based measurements of characteristics of atmospheric gas composition have been acquired at St. Petersburg State University (59°88' N, 29°83' E) since 1991. Equipment and techniques for interpreting the groundbased observations using measurements of spectra of direct solar IR radiation, zenith scattered UV and visible radiation are described. Main attention is centered on long-term variations of different trace gases, results of complex measurements of different atmospheric gases (O3, CO2, N2O, NO2, HF, HCl, HNO3 etc.) by Fourier spectrometer Bruker, comparisons of various ground-based methods for measuring the total columns of trace gases and the validation of different satellite measurements of total columns of trace gases. [ABSTRACT FROM AUTHOR]

Downward longwave irradiance (DLI) is important to understand climate change. To estimate the impact of major GHGs and regional change for downward longwave radiation, we used the observation data in five different climate regions, which are sites of the Baseline Surface Radiation Network (BSRN), and evaluated the contribution fraction (CONF) for DLI quantitatively with mstrn×, which had 14 bands for longwave radiation. The impact of variation of WV was strong in the bands from 2 to 3 (40-18.9 μm) under clear-sky condition. CONFs of WV were small in the bands from 4 to 6 (18.9-14.9 μm) because of the strong overlapping with CO2 in 15 μm absorption bands. [ABSTRACT FROM AUTHOR]