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Protonic ceramic fuel cells (PCFCs) offer a convenient means for electrochemical conversion of chemical energy into electricity at intermediate temperatures with very high efficiency. Although BaCeO3- and BaZrO3-based complex oxides have been positioned as the most promising PCFC electrolytes, the design of new protonic conductors with improved properties is of paramount importance. Within the present work, we studied transport properties of scandium-doped barium stannate (Sc-doped BaSnO3). Our analysis included the fabrication of porous and dense BaSn1−xScxO3−δ ceramic materials (0 ⩽ x ⩽ 0.37), as well as a comprehensive analysis of their total, ionic, and electronic conductivities across all the experimental conditions realized under the PCFC operation: both air and hydrogen atmospheres with various water vapor partial pressures (p(H2O)), and a temperature range of 500–900 °C. This work reports on electrolyte domain boundaries of the undoped and doped BaSnO3 for the first time, revealing that pure BaSnO3 exhibits mixed ionic-electronic conduction behavior under both oxidizing and reducing conditions, while the Sc-doping results in the gradual improvement of ionic (including protonic) conductivity, extending the electrolyte domain boundaries towards reduced atmospheres. This latter property makes the heavily-doped BaSnO3 representatives attractive for PCFC applications.

ilustraciones, diagramas, mapas Las heladas radiativas en Colombia son un fenómeno meteorológico de descenso de temperatura hasta 0 °C o menos, por enfriamiento nocturno, las cuales resultan nocivas principalmente para la producción agrícola en la región Andina del país. Por lo anterior y por la relevancia de las variaciones meteorológicas en la modulación del enfriamiento nocturno, se analizaron las condiciones atmosféricas a distinta escala espacial y temporal que pueden llegar a modificar la ocurrencia de heladas radiativas para Colombia. Se encontró que, dependiendo de la altitud sobre el nivel del mar, la proporción de heladas tiene un ciclo bimodal (zonas por encima de 4000 metros) con máximos en los trimestres a inicio y mitad de año, o unimodal (áreas inferiores a 4000 metros) con máximo en el trimestre inicial del año, en ambos casos por ser épocas de menor nubosidad, precipitación, humedad, temperatura y magnitud en los vientos. A escala diurna la mayor frecuencia de heladas se encuentra en las 06:00 horas y, además, se concluye que al menos 6 horas antes del inicio de estos eventos, se presentan anomalías negativas de nubosidad, humedad relativa, humedad específica, que generalmente son más severas a mayor altitud en la atmósfera. La evolución de la meteorología en la región alrededor de Colombia durante casos de helada otorga evidencia de que estas variaciones pueden no ser solo locales, sino que provienen de cambios en la meteorología a escala sinóptica, probablemente por intensificación de los vientos al norte del país y en dirección del nororiente. Finalmente, la simulación de casos de helada con el modelo atmosférico WRF, brinda una mejor aproximación de la variación espacial de la temperatura del aire para la zona Andina colombiana, lo cual permitió que se simularan heladas principalmente en zonas de alta montaña, aunque en zonas por debajo de los 3000 m.s.n.m. el modelo no presenta descensos de temperatura iguales a los registrados localmente. (Texto tomado de la fuente) Radiative frosts in Colombia are a meteorological phenomenon of temperature drop to 0 °C or less, due to night cooling, which are harmful mainly for agricultural production in the Andean region of the country. Due to the above and to the relevance of meteorological variations in the modulation of nocturnal cooling, the atmospheric conditions at different spatial and temporal scales that can modify the occurrence of radiative frosts for Colombia were analyzed. It was found that, depending on the topographical altitude, the threat of frost has a bimodal cycle (areas above 4,000 meters) with maximum in the quarters at the beginning and the middle of the year, or unimodal (areas below 4,000 meters). with a maximum in the initial quarter of the year, in both cases because these are periods of less cloudiness, precipitation, humidity, temperature and wind magnitude. On a daytime scale, the highest frequency of frosts is found at 06:00 hours and, in addition, it is concluded that at least 6 hours before the start of these events, there are negative anomalies of cloudiness, relative humidity, specific humidity, which are generally more severe at higher altitudes in the atmosphere. The evolution of the meteorology in the region around Colombia during frost cases provides evidence that these variations may not only be local, but they come from changes in the meteorology on a synoptic scale, probably due to the intensification of the winds to the north of the country and from north-east. Finally, the simulation of frost cases with the WRF atmospheric model provides a better approximation of the spatial variation of air temperature for the Colombian Andean zone, which allowed frost to be simulated mainly in high mountain areas, although in areas below 3000 m.a.s.l. the model does not present temperature drops equal to those registered locally. Maestría Magister en Medio Ambiente y Desarrollo Área Curricular de Medio Ambiente

A physical retrieval approach based on the one-dimensional variational (1D-Var) algorithm is applied in this paper to simultaneously retrieve atmospheric temperature and humidity profiles under both clear-sky and partly cloudy conditions from FY-4A GIIRS (geostationary interferometric infrared sounder) observations. Radiosonde observations from upper-air stations in China and level 2 operational products from the Chinese National Satellite Meteorological Center (NSMC) during the periods from December 2019 to January 2020 (winter) and from July 2020 to August 2020 (summer) are used to validate the accuracies of the retrieved temperature and humidity profiles. Comparing the 1D-Var-retrieved profiles to radiosonde data, the accuracy of the temperature retrievals at each vertical level of the troposphere is characterized by a root mean square error (RMSE) within 2 K except for at the bottom level of the atmosphere under clear conditions. The RMSE slightly increases in the higher atmospheric layers, owing to the lack of temperature sounding channels. Under partly cloudy conditions, the temperature at each vertical level can be obtained, while the level-2 operational products obtain values only at altitudes above the cloud top. In addition, the accuracy of the retrieved temperature profiles is greatly improved compared with the accuracies of the operational products. With respect to the humidity retrievals, the mean RMSEs in the troposphere in winter and summer are both within 2 g/kg. Moreover, the retrievals performed better compared with the ERA5 reanalysis data between 800 hPa and 300 hPa both in summer and winter in the RMSE sense.

This study presents experimental investigation into a novel UV cabinet type solar dryer designed for drying banana slices at the Chhattisgarh Swami Vivekanand Technical University (21 27′N, 81 43′ E). An experiment for the performance assessment of banana drying was conducted at the clear sky conditions. The solar dryer consists of 6 trays with the one drying chamber. The same technique is used for forced convection drying using the fan and the PV panel. Experimentally evaluated local metrological conditions such as solar radiation, atmospheric temperature, wind speed and air humidity. In the six trays for drying, 2 kg of banana slices were evenly divided and after a period of 16 h of drying, banana slices dried in the forced convection to moisture content of 13.75 % from an initial moisture content of 86.2%. On the other hand, natural convection drying reaches to 17.5% of the final moisture content, in the same time. Moisture ratio for the forced and natural convection drying varies in the range of 0.79–0.001 and 0.85–0.05, respectively. For the forced convection drying of banana slices the optimal and minimum drying efficiency of the designed solar dryer are 16.32 % and 0.29% whereas 13.75% and 0.15% of drying efficiency for natural convection drying are measured. The more efficient is forced convection drying in comparison with natural convection drying.

Studies on the atmospheric structure over the Antarctic Plateau are important for better understanding the weather and climate systems of polar regions. In the summer of 2017, an observational experiment was conducted at Dome-A, the highest station in Antarctica, with a total of 32 profiles obtained from global positioning system (GPS) radiosondes. Based on observational data, the atmospheric temperature, humidity and wind structures and their variations are investigated, and compared with those from four other stations inside the Antarctic circle. Distinguished thermal and dynamic structures were revealed over Dome-A, characterized by the lowest temperature, the highest tropopause, the largest lapse rate and the most frequent temperature and humidity inversion. During the experiment, a prominent blocking event was identified, with great influence on the atmospheric structure over Dome-A. The blocking high produced a strong anticyclone that brought warm and moist air to the hinterland of the Antarctic Plateau, causing a much warmer, wetter and windier troposphere over the Dome-A station. Meanwhile, a polar air mass was forced out of the Antarctic, formed a cold surge extending as far as Southern New Zealand and affected the weather there. Our results proved that there would be a direct interaction between the atmosphere over the hinterland of the Antarctic Plateau and middle latitudes with the action of a blocking high. Further studies are needed to explore the interaction between the atmospheric systems over the Antarctic and middle latitudes under intense synoptic disturbance, with long-term data and numerical modeling.

Background Acute type A aortic dissection (AAAD) is a life-threatening condition with high mortality within 24 hours. We hypothesized if there is a correlation between seasonal weather changes and the occurrence of AAAD. The aim of the present study was to identify seasonal specific weather and patient characteristics predicting the occurrence of AAAD. Methods This is a retrospective analysis of all consecutive patients of our department with AAAD between January 1st 2006 and December 31st 2016. The national meteorological department provided the data of temperature, humidity and air pressure during the study period. The occurrence of AAAD, preoperative neurological impairment and mortality were analyzed in correlation with the obtained daily weather data within the entire cohort and in patients with and without hypertension separately. Results A total of 517 patients were included. Mean age was 63.4±13 years, 69.4% were male and 68.8% had documented hypertension. In-hospital mortality was 17.7%. In the whole cohort, the occurrence of AAAD was significantly increased in March, October, December (P=0.016). In hypertensive patients, the occurrence was increased 34% with rising temperature (0.1-9.6 °C, OR1.34, 95% CI: 1.06-1.69, P=0.015). There was no correlation between weather variables and preoperative neurological impairment or mortality. Conclusions Our data suggests a relation between an increasing number of events of AAAD and certain months within our catchment area and a significantly increased occurrence with rising temperatures (independent from absolute temperature at time of the event) in hypertensive patients.

Accurate information on the thermal structures of tropical cyclones (TCs) is essential for monitoring and forecasting their intensity and location. In this study, a scene-dependent 1-D variation (SD1DVAR) algorithm is developed to retrieve atmospheric temperature and moisture profiles under all-weather conditions. In SD1DVAR, the background and observation error matrix varies according to the scattering intensity. Especially, the observation error matrix increases in precipitating atmospheres due to a larger uncertainty in the forward operator. With the data from the Advanced Technology Microwave Sounder (ATMS) onboard Suomi National Polar-orbiting Partnership (NPP) satellite, SD1DVAR can retrieve better thermal structures in the storm life cycle than NOAA Microwave Integrated Retrieval System (MIRS). Comparing with the aircraft dropsonde observations, the temperature and humidity errors from SD1DVAR are about 3 K and 20%, respectively, whereas those from MIRS are around 4 K–5 K and 30%, respectively. SD1DVAR is also applied for Microwave Temperature Sounder (MWTS) and Microwave Humidity Sounder (MWHS) onboard FengYun-3D (FY-3D) satellite. The MWTS and MWHS data sets are first combined into a single Comprehensive MicroWave Suite (CMWS) data stream and then used to retrieve the hurricane thermal structures. It is shown that the hurricane structure from CMWS is very similar to that from ATMS. However, due to the availability of 118-GHz measurements from the CMWS, the hurricane temperature vertical structure is better resolved, and the humidity error is also reduced by about 5%.

On a global and annual average, we find a parameterization in which the cloud cover increase is proportional to the mid tropospheric temperature increase, with a negative proportionality factor. If the relative humidity is conserved throughout the troposphere, a 1 °C heating (cooling) of the mid troposphere, decreases (increases) the cloud cover by 1.5 percentage points (pp). But if the relative humidity is not conserved, then the cloud cover decreases (increases) by 7.6 pp. If the shortwave reflection effect of the cloud cover is dominant on a global scale, this parameterization leads to a predominant positive feedback: if the temperature increases like in the current climate change, the cloud cover decreases and more solar radiation reaches the surface increasing the temperature even more. The contribution of the present work consists in finding that the negative sign of the proportionality factor is due to the Clausius–Clapeyron equation; that is, to the magnitude of the derivative of the saturation vapor pressure at the typical standard surface temperature of 288 K. The negative sign of the factor is independent on the conservation or non-conservation of relative humidity in the troposphere under climate change.

The evolution of the atmospheric temperature in the past, resulted from the EPICA project (European Project for Ice Coring in Antarctica) for the analysis of air bubbles in ice deposits near three weather stations in Antarctica, includes several glacial cycles. According to these studies, the glacial cycle consists of a slow cooling of the Earth’s surface at a rate of about 10−4∘C per year for almost the entire time of a single cycle (about 100 thousand years) and of a fast process of heating the planet, similar to a thermal explosion. The observed cooling of the planet follows from the imbalance of energy fluxes absorbed by the Earth and going into its surrounding space, and this imbalance is four orders of magnitude less than the accuracy of determination of the fluxes themselves. The inconsistency of the popular Milankovich theory is shown, according to which glacial cycles in the evolution of the Earth’s thermal state are associated with changes in the Earth’s orbit relative to the Sun. In considering the glacial cycle as the transition between the warm (contemporary) and cold thermal states of the Earth with a difference in their temperatures of 12 ∘C according to measurements, we construct the energetic balance for each of Earth’s states. The fast transition between the Earth’s cold and warm states results from the change of the Earth’s albedo due to the different volcano activity in these states. There is the feedback between the aggregate state of water covering the Earth’s surface and volcanic eruptions, which become intense when ice covers approximately 40% of the Earth’s surface. Dust measurements in ice deposits within the framework of the EPICA project confirms roughly a heightened volcano eruption during the cold phase of the glacial cycle. Numerical parameters of processes related to the glacial cycle are analyzed.

The aim of this study was to characterize the physicochemical properties and microbial communities of particulate matter (PM) in Seoul, Korea. We collected long-term (2017-2019) precipitation samples and PM10 and PM2.5 monitoring data to determine the impact of soluble and insoluble chemical species on the soil surface. Ambient PM10 concentrations were higher than PM2.5 concentrations during the monitoring period, but both decreased during rainfall due to the washing effect of precipitation. PM2.5 particles had a "fluffy" shape and contained sulfur (0.2%), but suspended particles (SPs) contained many carbon particles (approximately 60%). Spherical particles containing metal oxides, Fe and Al, might be originated from coal combustion, wild fires, and metal-refining processes under high-temperature conditions. Dissolved ions in precipitation included those eluted from salts and coal combustion based on the correlation coefficients of Na and Cl (R = 0.953) and F and NO3 (R = 0.706). The δ15N-NO3 and δ34S-SO4 of precipitation were enriched as the atmospheric temperature decreased from 9.8 to -1.6°C, implying the influence of domestic coal combustion. Backward trajectories showed that, in winter, air parcels passed through industrialized cities from China to South Korea. The microbial communities associated with PM were strongly influenced by atmospheric conditions. Proteobacteria (range from 4.6 to 76.7%) and Firmicutes (range from 6.0 to 91.4%) were the most dominant phyla and were significantly affected by changes in the PM2.5 environment. The results indicate that the acidity of precipitation and the composition of aerosols were affected by fossil fuel combustion and mineral dust, and that atmospheric conditions may change as PM2.5 concentrations increase.

The Real-Time Working Group (RTWG) of the International GNSS Service (IGS) is dedicated to providing high-quality data and high-accuracy products for Global Navigation Satellite System (GNSS) positioning, navigation, timing and Earth observations. As one part of real-time products, the IGS combined Real-Time Global Ionosphere Map (RT-GIM) has been generated by the real-time weighting of the RT-GIMs from IGS real-time ionosphere centers including the Chinese Academy of Sciences (CAS), Centre National d'Etudes Spatiales (CNES), Universitat Politècnica de Catalunya (UPC) and Wuhan University (WHU). The performance of global vertical total electron content (VTEC) representation in all of the RT-GIMs has been assessed by VTEC from Jason-3 altimeter for 3 months over oceans and dSTEC-GPS technique with 2¿d observations over continental regions. According to the Jason-3 VTEC and dSTEC-GPS assessment, the real-time weighting technique is sensitive to the accuracy of RT-GIMs. Compared with the performance of post-processed rapid global ionosphere maps (GIMs) and IGS combined final GIM (igsg) during the testing period, the accuracy of UPC RT-GIM (after the improvement of the interpolation technique) and IGS combined RT-GIM (IRTG) is equivalent to the rapid GIMs and reaches around 2.7 and 3.0 TECU (TEC unit, 1016¿el¿m-2) over oceans and continental regions, respectively. The accuracy of CAS RT-GIM and CNES RT-GIM is slightly worse than the rapid GIMs, while WHU RT-GIM requires a further upgrade to obtain similar performance. In addition, a strong response to the recent geomagnetic storms has been found in the global electron content (GEC) of IGS RT-GIMs (especially UPC RT-GIM and IGS combined RT-GIM). The IGS RT-GIMs turn out to be reliable sources of real-time global VTEC information and have great potential for real-time applications including range error correction for transionospheric radio signals, the monitoring of space weather, and detection of natural hazards on a global scale. All the IGS combined RT-GIMs generated and analyzed during the testing period are available at https://doi.org/10.5281/zenodo.5042622 (Liu et al., 2021b). his research has been supported by the China Scholarship Council (CSC). The contribution from UPC- IonSAT authors was partially supported by the European Union- funded project PITHIA-NRF (grant no. 101007599) and by the ESSP/ICAO-funded project TEC4SpaW. The work of An- drzej Krankowski is supported by the National Centre for Research and Development, Poland, through grant ARTEMIS (grant nos. DWM/PL-CHN/97/2019 and WPC1/ARTEMIS/2019)

Energetic particle precipitation (EPP) has the potential to change the neutral atmospheric temperature in the mesopause region. However, recent results are inconsistent, leaving the mechanism and the actual effect still unresolved. In this study we have searched for electron precipitation events and investigated a possible correlation between D-region electron density enhancements and simultaneous neutral temperature changes. The rotational temperature of the excited hydroxyl (OH) molecules is retrieved from the infrared spectrum of the OH airglow. The electron density is monitored by the European Incoherent Scatter Scientific Association (EISCAT) Svalbard Radar. We use all available experiments from the International Polar Year (IPY) in 2007–2008 until February 2019. Particle precipitation events are characterized by rapid increases in electron density by a factor of 4 at an altitude range of 80–95 km, which overlaps with the nominal altitude of the infrared OH airglow layer. The OH airglow measurements and the electron density measurements are co-located. Six of the 10 analysed electron precipitation events are associated with a temperature decrease of 10–20 K. Four events were related to a temperature change of less than 10 K. We interpret the results in terms of the change in the chemical composition in the mesosphere. Due to EPP ionization the population of excited OH at the top of the airglow layer may decrease. As a consequence, the airglow peak height changes and the temperatures are probed at lower altitudes. The observed change in temperature thus depends on the behaviour of the vertical temperature profile within the airglow layer. This is in agreement with conclusions of earlier studies but is, for the first time, constructed from electron precipitation measurements as opposed to proxies. The EPP-related temperature change recovers very fast, typically within less than 60 min. We therefore further conclude that this type of EPP event reaching the mesopause region would only have a significant impact on the longer-term heat balance in the mesosphere if the lifetime of the precipitation was much longer than that of an EPP event (30–60 min) found in this study.

Results of the study of the temperature in the mesopause region (∼87 km) based on measurement of OH (3-1) emission at the high latitude station Maimaga (63.04° N, 129.51° E) are presented and compared with the Aura (MLS) measurements of temperature at 0.002 hPa in 2013–2018 when flying over the Maimaga station. The average rotational temperature of OH (3-1) was compared with temperatures measured by Aura (MLS) and the background temperatures calculated from them. The results show more correct comparison of the OH (3-1) temperature with the background temperature calculated from Aura (MLS) data. The comparison confirms the observation of high temperatures in the mesopause in winter 2014/2015. In general, the temperature variations measured by two different methods are qualitatively consistent and answer the seasonal variations. Temperature differences can be explained by many factors, e.g., differences in measuring altitudes and techniques.

The atmospheric methane (CH4) concentration has increased in recent years due to natural and anthropogenic causes. Hence, it is essential to quantify the potential sources of CH4 to understand the factors responsible for its fluxes on a local to regional scale through in situ observations. Coastal wetlands, particularly the mangrove ecosystems in the tropical and subtropical coasts, are significant sources of CH4. In this study, we used an eddy covariance-based technique to measure the CH4 fluxes in a mangrove ecosystem in Pichavaram, South India. The daily mean CH4 flux ranged from 12 to 26 nmol m−2 s−1 during the wet season and from 6 to 20 nmol m–2 s–1 during the dry season. The monthly mean flux during the wet period was between 0.8 and 1.8 g CH4 m−2 month−1, and in the dry season, it was between 0.4 and 0.6 g CH4 m−2 month−1. The visual correlogram and structural equation modelling technique revealed that air temperature, creek water dissolved oxygen, soil organic carbon, and redox potential are important factors that control the CH4 fluxes. The results suggest that the Pichavaram mangrove wetland acts as a source for CH4. Our results also indicate that tidal inundation and seasonal variations in atmospheric temperature and water salinity are key factors affecting the CH4 flux in the Pichavaram mangrove ecosystem.

In this paper we analyzed spatial-temporal temperature changes in the upper troposphere/lower stratosphere (UTLS) above the Northern and Central Tien-Shan detected by satellite remote sensing which have been compared against seismic activity in (1992-2015). These anomalous changes in temperature time series were used as pre-seismic indicators. Anomalous variation parameters were calculated accounting for amplitude and phase of short-time temperature variations at UTLS isobaric levels separated by the tropopause. The results show that the spatial structure and dynamics of temperature anomalies in the area of UTLS have a sufficiently stable relation to seismic activity. We estimated the spatial and time variability of anomalous temperature perturbations on the basis of 12 strongest earthquakes with magnitudes Mï5.0. The temperature anomalies were observed in all considered cases from ~3 to 72 hours before the main seismic event.

Monitoring of the marine and coastal environment using standard measuring equipment is not without incurring a significant amount of cost. This study was geared at prospecting relatively inexpensive environmental monitoring instrument using the Raspberry Pi computer in combination with commonly available sensors. Atmospheric temperature, humidity, and sea surface temperature (SST) were monitored using locally assembled low-cost measuring equipment with a subsequent comparison with data from a standard weather station. The developed instrument was consequently evaluated for its efficacy and various functionalities in coastal environmental monitoring. DHT11 and DHT22 sensors are relatively cheap and both measure atmospheric temperature and humidity, while a DS19B20 waterproof digital thermometer measures water temperature. These sensors were incorporated in a locally built in situ measuring equipment interfaced by a Python-programmed Raspberry Pi for acquiring data. A successful assemblage and deployment of the device in a near-shore coastal marine environment yielded efficient and accurate data recorded by the DHT22 and DS19B20 sensors. A comparison of the DS18B20-measured SST to SST from Sentinel-3 satellite revealed no significant difference for a simple T-test and with R2 and root mean square error (RMSE) values of 0.172 and 2.15 °C respectively. Similarly, a comparison of atmospheric temperature and humidity between the developed equipment using DHT22 sensor, and the standard weather station yielded strong positive correlations (0.92 and 0.93) and with R2 of 0.71 and 0.58, and RMSE of 0.92 °C and 3.1% respectively. A transformation of the data from the developed equipment with respective regression equations yielded further significant improvements in the results with R2 values of 0.93, 0.84 and 0.87, and RMSE values of 0.63 °C, 0.68 °C and 1.74% respectively for SST (DS19B20), atmospheric temperature (DHT22) and humidity (DHT22). Although the DHT11 sensor recorded higher errors in atmospheric temperature and humidity data due to its low operating tolerance ranges, an application of respective regression equations also yielded improved results. This study has successfully demonstrated the potential of developing and using locally assembled relatively low-cost equipment for environmental monitoring where funding is a constraint for small-scale research and operational in situ observations.

Numerous paleoclimatic records from lake sediment cores in arid central Asia (ACA) suggest a more humid climate in the Little Ice Age (LIA) cold period than that of the contemporary warm period (the last century). Our high-resolution study of a sediment core from Yileimu Lake presents end members (EMs) of grain-size distributions (~5-year resolution), and major and trace elements (~10-year resolution), including the Chemical Index of Alteration (CIA) and Rb/Sr ratio. In contrast to records from these other lakes in ACA, our study indicates a warming and wetting trend in the southern Altay regional climate over the last five centuries. We suggest that continuously increasing snow/ice meltwater from the surrounding high mountains related to an increasing trend in atmospheric temperature, and increasing winter snowfall triggered by a decreasing trend in winter North Atlantic Oscillation (NAO) index, have dominated the regional climate in the southern Altay Mountains during 1620–1835 AD. We also suggest that temperature dependent evaporative losses greatly exceeding the water input to the lake, and reduced summer precipitation, caused the drought events during 1586–1620 and 1835–1870 AD. Heavy summer precipitation associated with significant increases in the local moisture supply induced by intense evaporation of snow/ice meltwater in the alpine and gorge terrain of the Altay Mountains played a critical role in the summer floods around the 1900s AD.

Covid-19 marked as a deadly pandemic hit the world in the early 2020’s. Stringent measures were implemented, to contain the virus. India first implemented lockdown on 25/03/2020 for 21 days (phase 1) and extended to 4 phases till 31 May 2020. During this lockdown, all socio-economic activities are put to a standstill. This resulted in a drastic improvement in the air quality. Although this being a temporary phenomenon, it plays a crucial role in studying atmospheric gases. This study makes an attempt to analyze the effect of the pollutants-PM2.5, PM10 and ozone combined with meteorological parameters-Relative Humidity (RH), Solar Radiation (SR) on the Ambient and Surface Temperatures (AT and LST). The data from 23 March 30 June for the consecutive years 2019 and 2020 have been considered. Each parameter is then plotted to study the trend for both the years and percentage differences are also calculated. To evaluate the synergic relation between the parameters, multiple linear regression analysis is done for each pollutant with meteorological parameters. Observations show a reduction in all the pollutants during the lockdown period. RH showed an increasing trend. Atmospheric temperature is reduced by 6o C to 10o C whereas the LST is noticed to increase by 3o C to 5o C. © 2021, World Research Association. All rights reserved.

In this paper, we present the Ku band signal strength relationship with rain rate and temperature. The correlation analysis of rain intensity with signal data indicates that rain rate negatively impacts the Ku band link while the atmospheric temperature has a strong positive correlation with the received signal strength. The statistical analysis showed that both temperature and rain intensity significantly influenced the received-signal strength data. This study is a preliminary analysis and aims to draw the association between a Ku band signal with rain intensity and temperature.

The purpose of the paper is to analyse the possible parameters of extratropical cyclones (ETCs) as they would occur in the Baltic Sea area at the end of the 21st century and in the past during the Holocene thermal maximum. Using a modelling system composed of the Weather Research and Forecasting (ARW-WRF) atmospheric model, Finite Volume Community Ocean Model (FVCOM), and surrogate background conditions, the results showed that changes in cyclone parameters are more profound under steeper climate change scenarios (RCP8.5) and under higher air temperatures. Most likely, the North Atlantic ETCs will become slightly stronger, but also the uncertainty increases. Nonlinear interactions between ice melt, North Atlantic current systems and atmospheric parameters probably induce an uncertainty both into future and past storminess reconstructions.

We investigated the relationship between the Arctic sea ice area and the following year’s atmospheric temperature using reanalysis data. The results demonstrate that the July air temperature at 850 hPa, observed over East Asia (EA) and Western North Pacific (WNP), shows a strong correspondence to the Arctic sea-ice area during the previous year’s September–November period. This relation has been observed since 2007. A strong relationship between the air temperature and the Arctic sea ice is observed only when the sea ice area in autumn is smaller than approximately 6.3 million km2. This threshold value coincides with the record reduction in the Arctic sea ice in the autumn of 2007. Sea surface temperature over the Northern Pacific also shows a similar correlation with the Arctic sea ice. The study of these correlations may provide a potential technique for seasonal prediction of July air temperature over EA and the WNP regions.

Observations of warm past climates and projections of future climate change show that the Arctic warms more than the global mean, particularly during winter months. Previous work has attributed this reduced Arctic land seasonality to the effects of sea ice or clouds. In this paper, we show that the reduced Arctic land seasonality is a robust consequence of the relatively small surface heat capacity of land and the nonlinearity of the temperature dependence of surface longwave emission, without recourse to other processes or feedbacks. We use a General Circulation Model (GCM) with no clouds or sea ice and a simple representation of land. In the annual mean, the equator-to-pole surface temperature gradient falls with increasing CO2, but this is only a near-surface phenomenon and is not caused by the change in total meridional heat transport, which is virtually unaltered. The high-latitude land has about twice as much warming in winter than in summer, whereas high-latitude ocean has very little seasonality in warming. A surface energy balance model shows how the combination of the smaller surface heat capacity of land and the nonlinearity of the temperature dependence of surface longwave emission gives rise to the reduced seasonality of the land surface. The increase in evaporation over land also leads to winter amplification of warming over land, although amplification still occurs without it. While changes in clouds, sea ice, and ocean heat transport undoubtedly play a role in high-latitude warming, these results show that enhanced land surface temperature warming in winter can happen in their absence for robust reasons.

High spectral resolution (or hyperspectral) infrared (IR) sounders onboard low earth orbiting satellites provide high vertical resolution atmospheric information for numerical weather prediction (NWP) models. In contrast, imagers on geostationary (GEO) satellites provide high temporal and spatial resolution which are important for monitoring the moisture associated with severe weather systems, such as rapidly developing local severe storms (LSS). A hyperspectral IR sounder onboard a geostationary satellite would provide four-dimensional atmospheric temperature, moisture, and wind profiles that have both high vertical resolution and high temporal/spatial resolutions. In this work, the added-value from a GEO-hyperspectral IR sounder is studied and discussed using a hybrid Observing System Simulation Experiment (OSSE) method. A hybrid OSSE is distinctively different from the traditional OSSE in that, (a) only future sensors are simulated from the nature run and (b) the forecasts can be evaluated using real observations. This avoids simulating the complicated observation characteristics of the current systems (but not the new proposed system) and allows the impact to be assessed against real observations. The Cross-track Infrared Sounder (CrIS) full spectral resolution (FSR) is assumed to be onboard a GEO for the impact studies, and the GEO CrIS radiances are simulated from the ECMWF Reanalysis v5 (ERA5) with the hyperspectral IR all-sky radiative transfer model (HIRTM). The simulated GEO CrIS radiances are validated and the hybrid OSSE system is verified before the impact assessment. Two LSS cases from 2018 and 2019 are selected to evaluate the value-added impacts from the GEO CrIS-FSR data. The impact studies show improved atmospheric temperature, moisture, and precipitation forecasts, along with some improvements in the wind forecasts. An added-value, consisting of an overall 5% Root Mean Square Error (RMSE) reduction, was found when a GEO CrIS-FSR is used in replacement of LEO ones indicating the potential for applications of data from a GEO hyperspectral IR sounder to improve local severe storm forecasts.

BCC-CSM2-HR is a high-resolution version of the Beijing Climate Center (BCC) Climate System Model (T266 in the atmosphere and 1/4∘ latitude × 1/4∘ longitude in the ocean). Its development is on the basis of the medium-resolution version BCC-CSM2-MR (T106 in the atmosphere and 1∘ latitude × 1∘ longitude in the ocean) which is the baseline for BCC participation in the Coupled Model Intercomparison Project Phase 6 (CMIP6). This study documents the high-resolution model, highlights major improvements in the representation of atmospheric dynamical core and physical processes. BCC-CSM2-HR is evaluated for historical climate simulations from 1950 to 2014, performed under CMIP6-prescribed historical forcing, in comparison with its previous medium-resolution version BCC-CSM2-MR. Observed global warming trends of surface air temperature from 1950 to 2014 are well captured by both BCC-CSM2-MR and BCC-CSM2-HR. Present-day basic atmospheric mean states during the period from 1995 to 2014 are then evaluated at global scale, followed by an assessment on climate variabilities in the tropics including the tropical cyclones (TCs), the El Niño–Southern Oscillation (ENSO), the Madden–Julian Oscillation (MJO), and the quasi-biennial oscillation (QBO) in the stratosphere. It is shown that BCC-CSM2-HR represents the global energy balance well and can realistically reproduce the main patterns of atmospheric temperature and wind, precipitation, land surface air temperature, and sea surface temperature (SST). It also improves the spatial patterns of sea ice and associated seasonal variations in both hemispheres. The bias of the double intertropical convergence zone (ITCZ), obvious in BCC-CSM2-MR, almost disappears in BCC-CSM2-HR. TC activity in the tropics is increased with resolution enhanced. The cycle of ENSO, the eastward propagative feature and convection intensity of MJO, and the downward propagation of QBO in BCC-CSM2-HR are all in a better agreement with observations than their counterparts in BCC-CSM2-MR. Some imperfections are, however, noted in BCC-CSM2-HR, such as the excessive cloudiness in the eastern basin of the tropical Pacific with cold SST biases and the insufficient number of tropical cyclones in the North Atlantic.

Precipitation is the key component determining the water budget and climate change of the Tibetan Plateau (TP) under a warming climate. This high-latitude region is regarded as “the Third Pole” of the Earth and the “Asian Water Tower” and influences the eco-economy of downstream regions. However, the intensity and diurnal cycle of precipitation are inadequately depicted by current reanalysis products and regional climate models (RCMs). Spectral nudging is an effective dynamical downscaling method used to improve precipitation simulations of RCMs by preventing simulated fields from drifting away from large-scale reference fields, but the most effective manner of applying spectral nudging over the TP is unclear. In this paper, the effects of spectral nudging parameters (e.g., nudging variables, strengths, and levels) on summer precipitation simulations and associated meteorological variables were evaluated over the TP. The results show that using a conventional continuous integration method with a single initialization is likely to result in the over-forecasting of precipitation events and the over-forecasting of horizontal wind speeds over the TP. In particular, model simulations show clear improvements in their representations of downscaled precipitation intensity and its diurnal variations, atmospheric temperature, and water vapor when spectral nudging is applied towards the horizontal wind and geopotential height rather than towards the potential temperature and water vapor mixing ratio. This altering of the spectral nudging method not only reduces the wet bias of water vapor in the lower troposphere of the ERA-Interim reanalysis (when it is used as the driving field) but also alleviates the cold bias of atmospheric temperatures in the upper troposphere, while maintaining the accuracy of horizontal wind features for the regional model field. The conclusions of this study imply how driving field errors affect model simulations, and these results may improve the reliability of RCM results used to study the long-term regional climate change.

We compare atmospheric temperature changes in satellite data and in older and newer multi-model and single-model ensembles performed under phases 5 and 6 of the Coupled Model Intercomparison Project (CMIP5 and CMIP6). In the lower stratosphere, multi-decadal stratospheric cooling during the period of strong ozone depletion is smaller in newer CMIP6 simulations than in CMIP5 or satellite data. In the troposphere, however, despite differences in the forcings and climate sensitivity of the CMIP5 and CMIP6 ensembles, their ensemble-average global warming over the satellite era is remarkably similar. We also examine four well-understood properties of tropical behavior governed by basic physical processes. The first three properties are ratios between trends in water vapor (WV) and trends in sea surface temperature (SST), the temperature of the lower troposphere (TLT), and the temperature of the mid- to upper troposphere (TMT). The fourth property is the ratio between TMT and SST trends. All four trend ratios are tightly constrained in CMIP simulations. Observed ratios diverge markedly when calculated with SST, TLT, and TMT trends produced by different groups. Observed data sets with larger warming of the tropical ocean surface and tropical troposphere yield atmospheric moistening that is closer to model results. For the TMT/SST ratio, model-data consistency depends on the selected combination of observed data sets used to estimate TMT and SST trends. If model expectations of these four covariance relationships are realistic, one interpretation of our findings is that they reflect a systematic low bias in satellite tropospheric temperature trends. Alternately, the observed atmospheric moistening signal may be overestimated. Given the large structural uncertainties in observed tropical TMT and SST trends, and because satellite WV data are available from one group only, it is difficult to determine which interpretation is more credible. Nevertheless, our analysis illustrates the diagnostic power of simultaneously considering multiple complementary variables and points towards possible problems with certain observed data sets.

A new system of local flat plate solar water heater “LPSH” recommended to be used for heating water as step for maximizing renewable source of energy instead of traditional power.The local flat plate solar water heater is used to heat water from the atmospheric temperature. Evacuated, double and single glasses flat plate solar water heater were fabricate with the same dimensions and installed at a latitude angle of 31 degree facing towards N-S direction.The experiment has been carried out at 24th March 2021 between 8.00 AM to 5.00 PM.The solar collector efficiency depends with many parameters such as type of glass cover, wind velocity and overall top loss heat transfer coefficient.Top loss heat transfer coefficient (Ut) plays an important role for design of solar collector.Taking this point under consideration the present work is to reduce the overall top loss heat transfer coefficient and improve the collector efficiency.The result shows that the efficiency of (LVDG) is higher compared to (LDG) and (LSG).The higher instantaneous and collector efficiency of (LVDG) obtain as a result of the overall top loss heat transfer coefficient (Ut) was reduced in (LVDG). The efficiency of (LVDG), (LDG) and (LSG) achieve around 79, 68 and 45 %, caused by the high heat increase at 12:00 pm.The efficiency decreased for (LSG) as a result of the high top loss heat transfer coefficient. The maximum overall top loss heat transfer coefficient Ut was recorded (2.51, 3.77, and 6.35 W/ m2 K) for (LVDG), (LDG) and (LSG) at 12:00 pm, respectively.

The El Nino/Southern Oscillation (ENSO) has a profound influence on global climate and ecosystems. Determining how the ENSO responds to greenhouse warming is a crucial issue in climate science. Despite recent progress in understanding, the responses of important ENSO characteristics, such as air temperature and atmospheric circulation, are still unknown. Here, we use a suite of global climate model projections to show that greenhouse warming drives a robust intensification of ENSO-driven variability in boreal winter tropical upper tropospheric temperature and geopotential height, tropical humidity, subtropical jets and tropical Pacific rainfall. These robust changes are primarily due to the Clausius–Clapeyron relationship, whereby saturation vapour pressure increases nearly exponentially with increasing temperature. Therefore, the vapour response to temperature variability is larger under a warmer climate. As a result, under global warming, even if the ENSO’s sea surface temperature remains unchanged, the response of tropical lower tropospheric humidity to the ENSO amplifies, which in turn results in major reorganization of atmospheric temperature, circulation and rainfall. These findings provide a novel theoretical constraint for ENSO changes and reduce uncertainty in the ENSO response to greenhouse warming. Greenhouse gas-induced warming intensifies atmospheric variability associated with the El Nino/Southern Oscillation, according to an analysis of global climate model projections.