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The shock response of fully-dense and porous crystalline tellurium dioxide (TeO 2) to the high-pressure and high-temperature fluid regime was investigated within the framework of density functional theory with Mermin's generalization to finite temperatures. The principal and porous shock Hugoniot curves were predicted from canonical ab initio molecular dynamics (AIMD) simulations, with the phase space sampled along isotherms up to 80 000 K, for densities ranging from ρ = 3 to 17 g/cm 3. The polymorphs investigated are α - Te O 2 paratellurite (P 4 1 2 1 2), Te O 2 cotunnite (P n m a), and Te O 2 post-cotunnite (P 2 1 / m). Based on the discontinuity found in the calculated U s − u p slope of TeO 2 post-cotunnite at a shock velocity of U s ≃ 8.35 km/s and a particle velocity of u p ≃ 3.64 km/s, the shock melting temperature and pressure are predicted to be ≃ 6500 K and ≃ 170 GPa. Results from the AIMD simulations are in line with the static compression data of Te O 2 paratellurite and cotunnite, and with the recent shock Hugoniot data for single-crystal α - Te O 2 for pressures up to 85 GPa, obtained using the inclined-mirror method and the velocity interferometer system for any reflector combined with powder gun and two-stage light-gas gun. [ABSTRACT FROM AUTHOR]

Background: Physical activity (PA) is an important contributor to one's physical and mental health both acutely and across the lifespan. Much research has done on the ambient environment's impact on PA; however, these studies have used absolute values of atmospheric measures such as temperature and humidity, which vary spatiotemporally and make comparisons between studies which differ in location or time of year difficult to square with one another. Methods: Here, we employ the Global Weather Type Classification, Version 2, to determine the combined impact of temperature and humidity on PA in a sample of insufficiently active young adults. We conducted secondary analyses of data from a single-group behavioral intervention trial that varied the number of digital messages sent daily. Young adults (n = 81) wore Fitbit Versa smartwatches for a 6-month period sometime between April 2019 and July 2020, and location was tracked using a custom smartphone application. Results: Mixed linear models indicated that, across 8179 person-days, PA was significantly lower on days with humid conditions and significantly higher on warm dry days, though the latter relationship was no longer significant when controlling for timing in relation to the COVID-19 pandemic declaration. Demographic factors did not affect the relationship between weather and PA. Conclusions: Results are a first step in providing additional guidance for encouraging PA in insufficiently active individuals given forecasted daily weather conditions. Future work should examine seasonal variability in the weather type–PA relationship without the influence of a world-altering event influencing results. [ABSTRACT FROM AUTHOR]

The giant impact between proto-Earth and a Mars-sized planet called Theia resulted in the formation of the Earth–Moon system, and the silicate mantles of the initial bodies may have partly been vaporized. Here, we develop a machine learning potential for MgSiO3 based on the data from first-principles calculations to estimate its critical point. The variations in pressure along different isotherms yield the position of the critical point of MgSiO3 at 0.54 g cm−3 and 6750 ± 250 K, which agrees with the previous theoretical estimation. We also simulate the MgSiO3 melt under a spectrum of critical conditions to understand the changes in coordination environment with density and temperature. The fourfold Si–O coordination hardly changes with increasing density at 3000 K. However, with increasing temperature, the dominance of four-coordinated Si–O diminishes rapidly as density decreases. Regarding Mg–O coordination, the overall trend, which varies with temperature and density, remains largely consistent with Si–O but with a greater diversity in the types of coordination due to more bond breaking events. Our work opens a new avenue by employing machine learning methods to estimate the critical point of silicates. [ABSTRACT FROM AUTHOR]

Lviv (Ukraine), a city of about 1 million inhabitants, is classified as a Western Forest-Steppe according to the forestry zonation. The mesoclimatic anomaly in the western forest-steppe with its humid mild climate is composed of the sum of microclimates formed by the thermal regime. As in every large city, Lviv has historically developed a distinctive microclimate influenced by many natural and anthropogenic factors, including global climate change, urban development, population growth, landscape fires, etc. This contributes to the development of a heat island effect, which is characterised primarily by an increase in air temperature and a decrease in air humidity and is a negative factor for the development of vegetation in the city's green zone. It was necessary to investigate the territory of the "dry island" -- the lower tier of the "heat island" -- to determine the level of vitality of the main woody plants located within these boundaries. As it could be observed, the "dry island" is located in the dense development of the central part of the city, where the temperature of the dead underlying surface (stone, asphalt, concrete) was in the range of 57-62 °C, the air temperature was 28.5-29.1 °C, and the humidity was 50.2--51.2%. Drought conditions affect the growth, development and reproductive capacity of woody plants. It has been established that the heat island should be reduced by urban greening in the horizontal and vertical ranges, and to maintain the physiological stability of tree plantations in the hot season, it is necessary to develop recommendations for the care of vegetation in the green zone of the city, depending on microclimatic indicators, especially air and soil temperatures, air and soil humidity. [ABSTRACT FROM AUTHOR]

One of the alternatives to control the impact of environmental problems is the existence of open space. In particular, the green open space included in the study is the urban forest. This research aimed to provide new scientific insights in identifying urban forest locations based on the criteria of Government Regulation Number 63 of 2002, as well as analyzing microclimate data through field observation activities and quantitative analysis. Urban forests based on these criteria are the South Sulawesi Governor's Office, Hasanuddin University, Pakui Sayang Park, Hasanuddin Park, Macan Park, and MoI (Maccini Sombala of Indonesia) Park. The highest level of vegetation density is in the Hasanuddin University area, and the South Sulawesi Governor's Office, which is 0.38. Meanwhile, the lowest is in Pakui Sayang Park, Hasanuddin Park, and MoI Park, which is 0.34. The air temperature in the Governor's Office and MoI Park is in the hot category, which is 30.9 °C, whereas the air temperature in other urban forests is in the very hot category, which is 31.1 °C to 31.8 °C. The air humidity in Pakui Sayang Park is 67.5 with a dry category, while the other urban forests are in the slightly dry category of 71.3% to 74.4%. Thermal comfort at all study sites is in the moderately comfortable category, wind speed is in the calm to shady category. The findings of this study highlight the importance of urban forests as one of the indicators that play an important role in overcoming the problem of increasing temperatures that have an impact on the comfort of people in urban areas. [ABSTRACT FROM AUTHOR]

In practical applications, the performance of ammonia-hydrogen fuel cells (AHFCs) is significantly affected by environmental factors and exhibits clear spatiotemporal characteristics. This paper simulated various environmental factors by altering the cathode air temperature, air humidity, oxygen concentration, air poisoning content, and exhaust back pressure based on an orthogonal experimental design, and then studied the spatiotemporal performance of AHFCs under multiple environmental conditions and calculated the impact of these factors on performance degradation and reversibility using the CatBoost algorithm. The results showed that when the relative humidity is reduced from 100% to 20% and the intake air is polluted by the highest level, the maximum output power of AHFC is reduced by 72% and 66.7% respectively. The degradation and reversibility of AHFCs change with the value of multiple factors, and any single factor is not absolutely dominant. Considering the coupling effects of environmental factors on the output performance of AHFCs, the weights of degradation attributed to air pollution level and humidity are 32.8% and 29.2%, respectively. The influences of oxygen concentration, temperature, and pressure decrease in that order. For reversibility, the weights attributed to air pollution level and relative humidity are 10.3% and 30.9%, respectively, while the weights of the other factors fall in between. • The spatiotemporal performance of AHFC under multiple environmental factors were studied. • The weight of environmental factors on its performance degradation and reversibility was calculated using the CatBoost algorithm. • The degradation and reversibility of AHFC depend on multiple factors, with no single factor being absolutely dominant. • For the weight of degradation, air pollution level and humidity accounted for 32.8% and 29.2% respectively. [ABSTRACT FROM AUTHOR]

Detecting the influence of temperature on urban vegetation is useful for planning urban biodiversity conservation efforts, since temperature affects several ecosystem processes. In this study, the relationships between land surface temperature (LST) and vegetation phenology events (start of growing season, SOS; end of growing season, EOS; peak phenology) was examined in native savannah woodland and grass parcels of a hot climate town. For comparison, similar woodland and grass parcels on the town's periphery, and a wetland, were used. The vegetation parcel LST values (°C) in one calendar year (2023) were obtained from Landsat-8 (L8) and Landsat-9 (L9) thermal imagery, whose combination yielded an 8-day image frequency. Phenology changes relative to seasonal air temperature and LST were determined using vegetation index (VI) values computed from accompanying 30 m resolution L8-L9 non-thermal bands: the Normalised Difference Vegetation Index (NDVI) and one improved VI, the Soil Adjusted Vegetation Index (SAVI). Higher imaging frequency, 250 m resolution NDVI and Enhanced Vegetation Index (EVI) MOD13Q1 layers supplemented the L8-L9 VIs. LST correlated highly with air temperature (p < 0.001). On nearly all L8-L9 image dates, the urban vegetation parcel's mean LST was higher (p < 0.001) than that at its peri-urban equivalent. Improved VIs (SAVI, EVI) detected some phenology events to have occurred slightly earlier than detected by the NDVI. Associated with the higher LST, the SOS was earlier in the urban than in the peri-urban woodland. This association has scarcely been demonstrated in savannah vegetation, necessitating proactive efforts to reduce potential biodiversity effects. [ABSTRACT FROM AUTHOR]

This paper selects three typical observation sites in Hengshui city, Hengshui Lake wetland, and youth woodland along the river, and uses non-contact infrared temperature measurement equipment to carry out high-temperature continuous observation of four kinds of underlay surfaces, namely, asphalt, grassland, woodland, and wetland, to compare the temporal characteristics of the surface temperature of each kind of underlay surface and its relationship with meteorological factors, and to establish the multivariate linear regression equations for the four kinds of maximum surface temperatures of underlay surfaces based on a variety of meteorological factors. Regression equations were established, and the main results were as follows: ①The daily maximum temperature, daily average temperature, and daily minimum temperature change curves of asphalt underlay were significantly higher than those of other underlay, and the change trends of grassland, woodland, and wetland were the same, and the curves were close to each other. ②The maximum and minimum temperatures of the four types of underlayment were ranked as asphalt > wetland > forestland > grassland. ③The maximum surface temperatures of the four types of underlayment were positively correlated with the daily maximum air temperature and solar radiation, with correlation coefficients around 0.9, and negatively correlated with the daily total cloudiness and the daily maximum relative humidity, with correlation coefficients above 0.5. ④The four types of sub surface maximum temperature forecasts are well fitted to the observed values, with correlation coefficients of 0.70 or more, and the error results are within the acceptable range, which can meet the needs of high-temperature forecasting, among which the grassy subsurface has the best fit, with a correlation coefficient of 0.90.The results have certain reference significance for knowing thermal environment of different urban underlying surfaces, while. providing scientific evidence for the development of refined urban meteorological forecasting services. [ABSTRACT FROM AUTHOR]

Predicting the distribution of climatically suitable areas for rice in China and identifying the key climatic factors can help optimize the rice planting layout and ensure food security. According to rice planting system in China, rice can be divided into early-season rice (ESR), mid-season rice and single-cropping late rice (MRSLR), and double-season late rice (DSLR). According to the actual growth period of ESR, MRSLR and DSLR, we calculated 36 climatic factors which may influence the distribution of climatically suitable areas and we employed MaxEnt model for prediction the climatically suitable areas of ESR, MRSLR and DSLR in historical period (2001–2020) and future periods (2041–2060 and 2081–2100). The key climatic factors for ESR are minimum air temperature of July, precipitation of driest month, precipitation of growth period and average air temperature of March; for MRSLR, the key climatic factors are minimum air temperature of coldest month, minimum air temperature of July and precipitation of wettest month; for DSLR, the key climatic factors are minimum air temperature of June, maximum air temperature of October and minimum air temperature of July. For ESR and DSLR, climatically suitable areas expand northwestward, with almost no climatically unsuitable areas. For MRSLR, climatically suitable areas expand northeastward, but climatically unsuitable areas appear in Guangxi, Guangdong, and Taiwan. The influence of climate change on the climatically suitable areas of rice in China exhibits significant regional differences, the unsuitable areas of rice are transforming into suitable areas. Attention should be focused on new suitable areas and new unsuitable areas. This study offers important scientific insights for the effective management and cultivation of rice. [ABSTRACT FROM AUTHOR]

In the paper performance of the prototype design of the condensation hood is analysed. Results of some experiments/measurements as well as results of CFD simulations are used to investigate the dependence of quantity called the condensation efficiency on selected working parameters. It was found that both the air inlet temperature and the air mass flow rate have significant impact on the performance of the heat exchanger. However, such changes did not influence the condensation efficiency which stays stable at the level of 100% for quite wide range of parameters changes. The same applies to the relative humidity of the inlet air. The only parameter which causes changes of the condensation efficiency is the steam mass flow rate when it exceeds 2.0 g/s. Nevertheless, operation of the hood with the steam mass flow rate up to ≈ 3.0 g/s guarantees that at least 90% of the steam is condensed. [ABSTRACT FROM AUTHOR]

Multi-split backplane cooling, a typical rack-level cooling technology, has the advantage of solving local hot-spot problems with huge energy-saving potential. These systems adopt the multi-split mode, and the operation effect is affected by terminal control performance. However, there are factors in the operation process, such as superheat degree (SH), rack airflow, evaporating/condensing pressures, etc., which improve the control complication, particularly under large head load differences among different terminals. Therefore, appreciative control strategies for outlet air temperatures of terminal evaporators, including single-loop control limited by minimum stable superheat degree (SLC) and fan/electronic expansion valve (EEV) double-loop control (DLC), are proposed considering that cooling performance can be affected by both refrigerant flow and airflow. Then, comparative simulation studies are carried out to evaluate energy efficiency, control effect, and feasibility under the condition of different server heat distribution characteristics. Results indicate that the DLC strategy achieves 23 % higher energy efficiency than the SLC strategy with a better temperature control effect when the inlet air temperature (IAT) difference between terminal evaporators is within ±5K. The SLC strategy has better reliability by more stable control of SH at IATs below 42°C, but it may lead to cooling failure when IATs exceed 42°C. An insufficient liquid supply problem may happen to the evaporator adopting the DLC strategy when the IAT is too high, which can be solved by adjusting the pressure differential between the evaporator and condenser. Moreover, the DLC system exhibits intense coupling effects, and how to decouple it is worthy of further study. [ABSTRACT FROM AUTHOR]

• A solid desiccant cooling system is optimised using a response surface methodology. • Regression models were developed and showed commendable predictive capability. • Multi-objective optimisation was achieved by considering four key parameters. • Case studies demonstrated the system's applicability in Australian climates. Solid desiccant-assisted dew-point indirect evaporative cooling (SD-DPIEC) systems have gained considerable attention as a potential eco-friendly alternative to vapour-compression cooling systems in building cooling applications. However, one major drawback of these systems is their substantial water consumption during evaporative cooling. To tackle this issue, this study aims to improve the cooling efficiency and water utilisation of an SD-DPIEC system using response surface methodology (RSM). This research focuses on optimising four key parameters: supply air temperature, humidity ratio, water consumption rate and coefficient of performance (COP). The independent variables encompass the ambient temperature, relative humidity, regeneration temperature, and recirculation air ratio. Employing a multi-objective optimisation approach via the desirability function, the optimised SD-DPIEC system is subsequently tested in two prevalent weather patterns in Australia. The results demonstrated that the regression models derived from RSM exhibited commendable predictive capability, with the determination coefficient R 2 and Adequate Precision exceeding 0.97 and 40.46, respectively. The outcomes revealed that the system attained its optimal performance with a supply air temperature of 20.36 °C, humidity ratio of 12.56 g kg-1, a water consumption rate of 3.11 kg/hr, and COP of 2.03 under the ambient temperature of 33.79 °C, relative humidity of 68.48 %, regeneration temperature of 51.78 °C, and recirculation air ratio of 60 %. Based on the optimisation results, a case study was undertaken to evaluate the system's applicability in representative Australian climates. The results demonstrated that the system could uphold air conditions with the supply air temperature below 19 °C and humidity ratio below 11.51 g kg-1 under the studied Australian climates. [ABSTRACT FROM AUTHOR]

• ⋅The adsorbent is regenerated in <30 min with humid air preheated to 200 °C. • ⋅Regeneration time depends less on the dew point as humid air temperature increases. • ⋅A heat source at 200 °C is obtained even with humid air unavailable latent heat. • ⋅Maximum temperature of generated humid air theoretically estimated exceeded 220 °C. To reuse low-temperature wasted heat as a thermal resource for high temperature, a direct-contact adsorption thermal storage was focused using humid air and zeolite 13X particles as the working fluid and adsorbent, respectively. Only a few previous studies have chosen the working fluid in gaseous form because it is unavailable for latent heat in generating heat sources. Recovering waste heat in humid air to generate hotter steam is unique and becomes an originality of our present work. The time required to regenerate zeolite particles and the maximum temperature of the generated steam were investigated assuming a warm-up device for a vehicle. The time required to regenerate zeolite was investigated by changing the dew point, temperature, and superficial velocity of the inlet humid air. It was mainly affected by the temperature of the inlet air. The absorbent was regenerated within 30 min when the humid air preheated to 200 °C was supplied. On the other hand, the maximum steam temperature was investigated by changing the superficial velocity and temperature of saturated inlet humid air. As one of the significant and novel finding in this work, the steam of >200 °C was obtained as a high-temperature heat source even with saturated humid air unavailable latent heat. Moreover, as theoretical knowledge, it was revealed that the maximum temperature of the heat source can be estimated by the relationship between the heat balance on the packed bed and adsorption equilibrium. [ABSTRACT FROM AUTHOR]

A slight increase in air or soil temperature above the optimal range for potato cultivation can affect its performance in different regions of the world. To assess the potential impacts of future climatic conditions in southern Chile, a field experiment was conducted in two growing seasons (2021/2022 and 2022/2023) to examine the effects of an increase in air (+ 3–4 °C) and soil (+ 2–3 °C) temperatures on biomass accumulation and growth dynamics of one modern potato genotype and three Chilean native potato genotypes. To increase the temperature during the entire crop cycle, passive heating systems (i.e. open-top chambers and polyethylene mulch) were employed in this study. Our results showed that the commercial genotype Asterix had a yield reduction across all warmer treatments due to increased air and/or soil temperature. In contrast, the Chilean native potatoes had a comparative advantage against high air temperatures but not against higher soil temperatures. As expected, tuber yield changes coincided with variations in architecture and growth dynamics, differing among the different potato genotypes. Warmer soils would strongly influence the partitioning of assimilates to tubers, resulting in lower yields at higher temperatures. [ABSTRACT FROM AUTHOR]

An extremely efficient green protocol for palladium acetate-catalysed ligand-free Suzuki–Miyaura cross-coupling reactions of aryl/heteroaryl bromides with aryl/substitute aryl boronic acids in neat 'Water Extract of Leaf Ash of Neem' (WELAN)' was developed. This method offers a simple, mild, efficient and highly cost-effective alternative to the existing protocols since the reaction proceeds in natural feedstock WELAN at room temperature in air at very short reaction times (5–60 min) under ligand/external base/promoter/organic medium free conditions. Here WELAN has been found to be the effective base and reaction medium for this cross-coupling reaction with high turnover number (TON). This manuscript also theoretically depicts the probable mechanism of WELAN catalysed cross-coupling reaction. [ABSTRACT FROM AUTHOR]

In this research paper, thin-layer convective drying characteristics for Jamun (Indian Blackberry) slices were analyzed at 50 to 80°C air drying temperatures with an interval of 10°C and an air velocity of 0.5 m/s. During the drying investigation, it was found that it occurred only in a range of falling periods of drying. With drying air temperature increment, the duration of drying was significantly reduced. Moisture removal took place from initially at 83.68 (% wb) to finally around 2.88 (% wb) in the tray dryer. The experimental observations were verified with various drying models of thin-layer. By nonlinear regression analysis, the selected drying model parameters were determined. Between the experimental and estimated moisture ratios, the selected drying models were examined with the help of r-squared (r2), Mean Absolute Percentage Error (MAPE), Chi-square (χ2) and Root Mean Squared Deviations (RMSD). As a result, it was found that the Page model was fitted satisfactorily at 50 and 60°C air drying temperatures while the model developed by Midilli et al was fitted satisfactorily at 70 and 80°C air drying temperatures to characterize Jamun slices with convective drying curves. The effective diffusion of water and activation energy values were estimated as 2.79–7.71×10−9 m2/min and 30.82 kJ/mol respectively for Jamun slices. [ABSTRACT FROM AUTHOR]

This study attempts to answer the question: If global warming were to increase by 1.5°, 2° and 3°C (compared to the pre-industrial baseline of 1850–1900), at what rate would South Asia be warming? A basis for influencing climate policy-making in India and countries part of the South Asian Association for Regional Cooperation (i.e., SAARC, including Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka) has been put forth. IPCC provides tools for analyzing mean near-surface air temperature data using CMIP6 (global climate model) and CORDEX-SA (regional climate model). This study reports the generated outputs from both projection models by analyzing and comparing data to better understand climate change in the region. While CMIP6 provided a coherent overall picture of South Asia, CORDEX-SA projected the average temperature variations of Indian states better. The decreasing order in which Indian states are expected to be affected by average temperature rise is Himalayan states from north to north-east; northwestern and western states along the Pakistan border; western coastline along the Arabian Sea; southern states along the eastern coastline (Bay of Bengal); central and eastern states. Both models projected the temperature rise in the Indian state of West Bengal to be the highest in the coming decades. Among SAARC nations, Afghanistan was projected to be the most affected and Bangladesh the least, following the same pattern of temperature variation as the Indian regions neighbouring them. Further, it was found that a mean temperature rise of 1.5° and 3°C would occur over South Asia in the timeframe of 2035–2038 and 2062–2068, respectively. Regarding monthly variation, temperature rise is expected to affect the period of January (average 1.35°C rise) to April (average 1.05°C rise) the most. [ABSTRACT FROM AUTHOR]

To generate a concentrated photovoltaic-thermal (CPVT) unit system, linear Fresnel concentrators have been attached to a PV unit and a thermoelectric generator (TEG) has been combined in this work to boost productivity. In the presence of concentrators, the temperature of the silicon layer increases. While electrical output is enhanced for the CPVT unit, the non-uniform isotherms can decrease the lifetime of the panel, so confined jets of alumina-water nanofluid have been applied for cooling. To validate the numerical code, previous papers were examined and good accommodations were reported. Various values of the inlet temperature (Tin) and velocity (Vin) of jets have been analysed. The impacts of installing concentrators on overall performance and CO2 mitigation have been investigated. An increase in Vin leads to an incremental increase in thermal performance of about 4.2% and thermal uniformity is enhanced by about 13.91%. The thermal power of the system is enhanced by about 2.19 times as a result of adding concentrators. Also, the PV power is enhanced by 86.22% in the presence of the reflectors. With the increase in Tin, the thermal and electrical performance decrease by about 19.95% and 5.24%, respectively. Installing concentrators enhances the overall performance by about 6.55%. After 10 years, the amount of CO2 mitigation for the CPVT-TEG system reaches 148.28 ton. [ABSTRACT FROM AUTHOR]

Estimation of reference evapotranspiration values is crucial in climatological and hydrological research, agricultural engineering, and irrigation design. The Penman-Monteith method, endorsed by the Food and Agriculture Organization (FAO) of the United Nations and numerous research studies, is widely regarded as the gold standard. However, its extensive data requirements limit its applicability in regions with sparse meteorological networks or limited measurement capabilities. The Hargreaves method, which requires only basic air temperature inputs, offers an alternative solution. The aims of this study were to calibrate the Hargreaves model for Central European climate conditions, considering altitudinal dependence, and to evaluate the temporal stability of the model parameters. In the first part of the research, we regionalized the Hargreaves coefficients using a curve-fitting method to ensure the best accuracy across 60 climatological stations in Slovakia. The regionalization of the Hargreaves coefficient improved accuracy by 10.1%, reducing the weighted absolute percentage error (WAPE) to 17.9%. However, our results showed that the accuracy of the modified Hargreaves model decreased with the increasing altitude of a climatological station. Incorporating altitude into the Hargreaves equation significantly improved model accuracy in stations at higher altitudes, providing a consistent level of accuracy across all climatological stations, regardless of their location and altitude. The results also indicated that the optimal model coefficient values change over time, showing a decreasing trend of –0.5 for the B coefficient and –0.1 for the C coefficient between the periods 1981–2000 and 2001–2020. Although regionalizing the Hargreaves model coefficients for local conditions can achieve good model performance, the model's accuracy is not stable over time. Thus, periodic validation of the model is necessary for short-term applications. [ABSTRACT FROM AUTHOR]

The diversity of natural conditions of the Crimean Peninsula determines different regimes of the main meteorological characteristics that determine the water availability for the territory. The estimation of the spatiotemporal heterogeneity of these characteristics and the solution of the problem of gaps in the ground-based observation data can be based on the results of calculations by general circulation models of the Earth's atmosphere with assimilation of ground-based observation data, also known as atmospheric reanalysis. Estimates of the quality of reproduction of the surface air temperature and the total precipitation by atmospheric reanalysis models EWEMBI, ERA5-Land, and MSWEP are given and compared with data from ground-based meteorological observations. The main characteristics of the data sets used (both observational and calculated), the main verification methods, the results of estimates and the conclusions regarding the applicability of the data used in simulation problems are given. The mean errors of the models in air temperature and the amount of precipitation over various averaging periods (day, month, year) are given. Thus, the mean coefficients of correlation over different averaging periods vary within 0.74–0.97 for temperature and 0.52–0.79 for precipitation. The results show that all model reproduce the values of the temperature and total precipitation over different averaging periods with an acceptable accuracy; however, all of them show a tendency toward underestimation of the daily sums of precipitation along with an overestimation of the number of days with precipitation. [ABSTRACT FROM AUTHOR]

This study examines runoff generation processes by focusing on new, young, and old water fractions in the stream discharge within the Swiss pre-Alpine Alp catchment and its smaller tributaries, Erlenbach and Vogelbach. Young water represents a contribution from the three most recent rainfall-runoff events. This research utilises a four-year time series of daily stable water isotope data from stream water and precipitation to investigate seasonal variations. An extended two-component hydrograph separation method is applied to analyse the catchment water and tracer mass balance across both the event and pre-event time axes. The calculated new, young and old water components in stream discharge help estimate time-varying backward travel time distributions. Factors such as air temperature, snow depth, and evapotranspiration data are considered to understand isotope fractionation because of phase changes. The results suggest that discharge generated in autumn and winter may have longer backward travel times compared with spring or summer discharge. Additionally, forest cover influences water fractions older than 40 days. The study identifies a nivo-pluvial runoff regime, with new water fractions peaking in August (Erlenbach, Vogelbach) and January (Alp). Young water fractions reach their highest levels at the start of winter and during snowmelt, while old water fractions peak towards the end of snowmelt and in mid-autumn. The Alp catchment and its tributaries exhibit higher new and young water components than old water following a month of low precipitation and high evapotranspiration in July. These findings are significant in light of the projected drier summers in Central Europe. [ABSTRACT FROM AUTHOR]

The building sector is one of the largest final consumers of energy, especially for air conditioning, and research has shown that there is a great potential for energy savings in this sector. The performance of a chiller can vary significantly depending on system partial loads and evaporator and condenser operating temperatures. The condensers of water-only chillers take the heat of condensation from the refrigerant only through the sensible heat of the refrigerant, leading to significant water flows. The outside air temperature and the intensity of solar radiation directly influence the consumption of electricity on the chiller. Having available the values for the solar radiation intensity I [W/m2 ] and the outside air temperature te [⁰C], with the help of the proposed mathematical model, validated by experimental measurements, the optimal values for the minimum electricity consumption of the system are obtained, under the conditions which the chilled water temperature is 7/12⁰C and the indoor air temperature is 27⁰C [ABSTRACT FROM AUTHOR]

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The aim of this study was to present the characteristics of a hot airflow in a conveyor type dampers under the hot air temperature changes. The amount of space occupied by the damper was reduced by 50 %, and by efficiently managing the damper's airflow rate even in the face of extreme external conditions and constant air volume proportional control, a conveyor-type damper with a significant energy-saving effect has been explored. It was configured to control the degree to which it was opened by operating the folding conveyor drive mechanism, enabling the damper to modify airflow. In this study, the mass flow rate of heated air through the conveyor-type damper increased in proportion to the damper port's expansion. The mass flow rate of air decreased as the temperature of air intensified. In addition, the thermal energy of the air flowing in the conveyor-type damper improved in ratio to the increase in the damper opening. The findings indicate a 50 % reduction in the damper's occupied space, indicating a significant energy-saving impact of the conveyor-type damper. This is because the damper's air volume is effectively controlled even in the face of severe external conditions, as it is proportionately controlled throughout. The understanding of the properties of airflow for the hot temperature change is strengthened by this research. Furthermore, this study may provide useful direction for future research and industry optimization. [ABSTRACT FROM AUTHOR]

Air staging in solid fuel combustion features widely in small scale domestic boilers to large scale moving grate combustors. Whilst the effects of air staging on the combustion characteristics of these systems are generally known, there is very little insight available into the role of secondary air on the flow and temperature field in the freeboard of batch-type fixed bed biomass combustors. Three-dimensional gas phase simulations using the Transition kl- and Finite Rate/Eddy Dissipation models were validated against freeboard temperatures and emissions (CO2 and O2) measured on the same set-up. Results show that secondary air at Qs/Qt ≥0.25 induces two recirculation zones, upstream and downstream of its injection point with maximum freeboard temperatures generally observed around these recirculation zones, if Qs/Qt drops to 0.12-0.18 only an upstream recirculation zone is observed until it diminishes by Qs/Qt = 0.06. However, there is a trade-off caused by what appears to be a cooling effect if Qs/Qt is increased between 0.25 and 0.71. Modelling results show that in reacting cases, unlike non-reacting modelling on the same geometry, the strength of the secondary air induced upstream recirculation zone appears significantly stronger. [ABSTRACT FROM AUTHOR]

This study attempts to predict the maximum temperature, along with the number of heat wave days (HWDs) at lead times of 7 and 15 days over Rajasthan, i.e., a semiarid region, using four machine learning (ML) algorithms, namely, artificial neural networks (ANN), support vector regression (SVR), random forest (RF), and eXtreme gradient boosting (XGBoost). It uses five key atmospheric variables, i.e., air temperature, geopotential height, relative humidity, U-wind, and V-wind, to predict the daily maximum temperatures for the months of April, May, and June, for the period from 1991 to 2020. The ML models are developed by using spatially averaged atmospheric variables and daily maximum temperature. The study demonstrates decent accuracy in forecasting the total annual count of HWDs and daily maximum temperature for Rajasthan for the 7-day lead time. However, as the lead time extends to 15 days, the model performances experience a decline. While comparing the performances of the four models, the SVR outperforms ANN, RF, and XGBoost in prediction. The findings of the current study indicate the potential utility of spatiotemporal dynamics in meteorological variables for long-term heat wave prediction. Moreover, the successful performances of the considered models, i.e., ANN, SVR, RF, and XGBoost, exhibit substantial future potential for reliable application in this context. [ABSTRACT FROM AUTHOR]

Changes in the soil freeze–thaw status will inevitably affect the thermal conditions and properties of the Tibetan Plateau (TP), thereby affecting its upper atmosphere, and further afield in East Asia and even globally. In this study, using the soil temperature simulated by the Community Land Model Version 5.0 (CLM5.0), the timing and duration of the soil freeze–thaw status were divided into freeze start‐date, freeze end‐date and freeze duration. Then, using linear trend estimation, correlation analysis and other methods, the changes in the spatiotemporal distribution of the timing and duration of the soil freeze–thaw status from 1979 to 2018 over the TP were analysed, and the relationships between them and surface temperature, altitude and latitude were analysed. The results obtained were as follows: (1) The soil temperature simulated by CLM5.0 can reasonably reproduce the seasonal changes in multilayer soil temperature, and correlated well with observations. Simulated by CLM5.0 of the time and duration of the soil freeze–thaw status also correlated well with observations. (2) The spatial distribution of the soil freeze–thaw status is characterized by a trend of delayed freezing, advanced thawing and shortened freeze duration from northwest to southeast over the TP. From 1979 to 2018, the freeze start‐date postponed by 7.3 days and became delayed at a rate of 1.9 days per decade, while the freeze end‐date advanced by 6.4 days at a rate of 1.7 days per decade, and the freeze duration shortened by 13.7 days at a rate of 3.6 days per decade. The timing and duration of the soil freeze–thaw status vary across different regions of the TP. The freeze start‐date in all areas of the TP has been delayed in the past 39 years. Except for the subcold zone and arid regions of the TP, the freeze end‐date has occurred earlier and the freeze duration has shortened, with the most significant changes in the subcold zone and humid regions, while the freeze end‐date has advanced at a rate of 3.6 days per decade and the freeze duration has shortened at a rate of 6.3 days per decade. (3) The timing and duration of the soil freeze–thaw status are significantly correlated with surface air temperature, elevation and latitude, exceeding the 99% confidence level. The correlation between the timing and duration of the soil freeze–thaw status and surface temperature is strongest, followed by altitude, and correlation with latitude is weaker. The correlation between surface air temperature and the timing and duration of the soil freeze–thaw status in the western TP is stronger than that in the eastern TP. The rate of change in the soil freeze–thaw status increases with altitude to 3000 m above sea level, while this rate decreases with elevation above 3000 m. The rate of change in the soil freeze–thaw status is greatest at 29°N, while the rate of delay in the freeze start‐date is minimal at 33°N and the rates of advancement in the freeze end‐date and shortening of the freeze duration are minimal at 35°N. [ABSTRACT FROM AUTHOR]

The Hyperspectral Infrared Atmospheric Sounder Type II (HIRAS-II) aboard the Fengyun 3E (FY-3E) satellite provides valuable data on the vertical distribution of atmospheric states. However, effectively extracting quantitative atmospheric information from the observations is challenging due to the large number of hyperspectral sensor channels, inter-channel correlations, associated observational errors, and susceptibility of the results to influence by trace gases. This study explores the potential of FY-3E/HIRAS-II to atmospheric loadings of SO2 from volcanic eruption. A methodology for selecting SO2 sensitive channels from the large number of hyperspectral channels recorded by FY-3E/HIRAS-II is presented. The methodology allows for the selection of SO2-sensitive channels that contain similar information on variations in atmospheric temperature and water vapor for minimizing the influence of atmospheric water vapor and temperature to SO2. A sensitivity study shows that the difference in brightness temperature between the experimentally selected SO2 sensitive channels and the background channels effectively removes interference signals from surface temperature, atmospheric temperature, and water vapor during SO2 detection and inversion. A positive difference between near-surface atmospheric temperature and surface temperature enables the infrared band to capture more SO2 information in the lower and middle layers. The efficacy of FY-3E/HIRAS-II SO2 sensitive channels in quantitively monitor volcanic SO2 is demonstrated using data from the 29 April 2024 eruption of Mount Ruang in Indonesia. Using FY-3E/HIRAS-II measurements, the spatial distribution and quantitatively information of volcanic SO2 are easily observed. The channel selection can significantly enhance the computation efficiency while maintain the accuracy of SO2 detection and retrieval, despite the large volume of data. [ABSTRACT FROM AUTHOR]

ABSTRACT Urban areas experience the impact of natural disasters, such as heatwaves and flash floods, disparately in different neighbourhoods across a city. The demand for precise urban hydrometeorological and hydroclimatological modelling to examine this disparity, and the interacting challenges posed by climate change and urbanisation, has thus surged. The Weather Research and Forecasting (WRF) model has served such operational and research purposes for decades. Recent advancements in WRF, including enhanced numerical schemes and sophisticated urban atmospheric‐hydrological parameterizations, have empowered the simulation of urban geophysical processes at high resolution (~1 km), but even this resolution misses significant urban microclimate variability. This study applies the large‐eddy simulations (LES) mode within WRF, coupled with single‐layer urban canopy models (SLUCM), to enable even finer‐scale modelling (150 m) of the Urban Heat Island (UHI) effect in the Baltimore metropolitan area. We run nine scenarios to evaluate various methods of initializing soil moisture and various spinup lead times, and to assess the impact of WRF's Mosaic approach in depicting subgrid‐scale processes. We evaluate the scenarios by comparing the WRF simulated land surface temperature (LST) against Landsat LST and the WRF simulated hourly 2‐m air temperatures (AT) with observations from eight weather stations across the domain. Results underscore the paramount influence of the lead spinup time on the spatiotemporal distribution of simulated soil moisture, consequently shaping WRF's efficacy in predicting the UHI. Furthermore, interpolating soil moisture‐related parameters from the parent for child domain initialization yields a notable reduction in mean and root‐mean‐squared errors. This improvement was particularly evident in simulations with the longest spinup time, affirming the importance of carefully designing the initialization of soil moisture for improved urban temperature predictions. [ABSTRACT FROM AUTHOR]

The aim of this numerical study is to investigate the heat transfer characteristics of the air flowing in the triangular photovoltaic thermal (PV/T) array/system at variable velocities. The PV/T array in the present analysis is composed of seven photovoltaic (PV) panels connected in series along with a triangular duct throughout its length. The heat transfer analysis in the PV panel (solid component) and visualization of temperature distribution in the PV/T system has been simulated by the use of system coupling of steady state thermal and CFX tools in ANSYS 18.2. Experiment was initially performed at velocity of 1.5 m/s inside the duct by the use of ANSYS software to predict the glass temperature, outlet air temperature, and tedlar temperature of triangular PV/T system. Further, the velocity has been incremented by 1 m/s up to 6.5 m/s to see the overall performance of the system. The validation of simulation results showed a good agreement with the experimental results under reasonable limit. The gain in temperature with the increase in velocity becomes marginal (only 7%) after 4.5 m/s. The temperature contours from the numerical simulation also revealed that cooling up to the last panel is not significant beyond 4.5 m/s. Similar tendency is documented in the overall exergy efficiency which significantly increased to 4.5 m/s and became marginal with further increment in velocity. It can be inferred that the optimum velocity which can fulfill the requirement of cooling of all PV panels along with reasonable thermal output is 4.5 m/s. The thermal energy gain gradually increases as the day progresses and becomes maximum at 2:00 PM. The average thermal energy gain being 9.6% higher than that in the morning (10:00 AM) indicates its suitability for applications requiring moderately high temperature. The present numerical investigation focuses on improving the overall performance of the system without the involvement of any additional cost. The system can be used in various applications like crop drying, space heating, etc. Owing to different outlet air temperatures during the day, the applications can either be utilized independently or can be combined to be used at different times according to the temperature requirement. [ABSTRACT FROM AUTHOR]

The Hyperspectral Infrared Atmospheric Sounder Type II (HIRAS-II) aboard the Fengyun 3E (FY-3E) satellite provides valuable data on the vertical distribution of atmospheric states. However, effectively extracting quantitative atmospheric information from the observations is challenging due to the large number of hyperspectral sensor channels, inter-channel correlations, associated observational errors, and susceptibility of the results to influence by trace gases. This study explores the potential of FY-3E/HIRAS-II to atmospheric loadings of SO2 from volcanic eruption. A methodology for selecting SO2 sensitive channels from the large number of hyperspectral channels recorded by FY-3E/HIRAS-II is presented. The methodology allows for the selection of SO2-sensitive channels that contain similar information on variations in atmospheric temperature and water vapor for minimizing the influence of atmospheric water vapor and temperature to SO2. A sensitivity study shows that the difference in brightness temperature between the experimentally selected SO2 sensitive channels and the background channels effectively removes interference signals from surface temperature, atmospheric temperature, and water vapor during SO2 detection and inversion. A positive difference between near-surface atmospheric temperature and surface temperature enables the infrared band to capture more SO2 information in the lower and middle layers. The efficacy of FY-3E/HIRAS-II SO2 sensitive channels in quantitively monitor volcanic SO2 is demonstrated using data from the 29 April 2024 eruption of Mount Ruang in Indonesia. Using FY-3E/HIRAS-II measurements, the spatial distribution and quantitatively information of volcanic SO2 are easily observed. The channel selection can significantly enhance the computation efficiency while maintain the accuracy of SO2 detection and retrieval, despite the large volume of data. [ABSTRACT FROM AUTHOR]

Urban heat stress is a critical issue, particularly in cities where dense infrastructure and limited green space exacerbate temperature extremes. This study investigates the impact of greenery (EVI2), canopy cover (CC), impervious cover (IC), and water bodies on heat index in Chicago using high‐resolution data from the Heat Watch campaign. We find that EVI2, CC and proximity to water body significantly reduce heat while IC increases heat, particularly in the afternoon when solar radiation is intense. Additionally, the effective radius that land cover impacts heat is smaller in the afternoon. The combined effect analysis indicates that enhancing total greenness, not just canopy cover, is the most effective strategy to reduce heat. This study underscores the importance of strategic vegetation management, highlighting the critical role of integrated approaches in reducing urban heat. Plain Language Summary: This study looks at how greenery, tree canopy cover, impervious surfaces (like concrete), and water bodies affect air temperature in Chicago. Using detailed air temperature data from the Heat Watch campaign, we found that vegetation and proximity to water significantly reduce temperatures, while impervious surfaces increase temperatures, especially in the afternoon when the sun is strongest. The influence of these factors on temperature is more localized in the afternoon. Our analysis shows that increasing overall greenery, not just tree canopy cover, is the most effective way to reduce heat. This study highlights the importance of strategic vegetation management and integrated approaches to effectively reduce urban heat. Key Points: Greenery, canopy cover, and proximity to water lower heat index, while impervious cover raises heat index, especially in the afternoonInteractions exist between greenery, canopy cover, and impervious cover, affecting their combined impact on heat indexSelecting impactful areas and using integrated approaches are crucial for effective urban heat reduction [ABSTRACT FROM AUTHOR]

Global reanalyzes are widely used for investigations of Antarctic climate variability and change. The European Centre for Medium‐Range Weather Forecasts 5th generation reanalysis (ERA5) is well regarded and spans 1940 to today. We investigate whether ERA5 reliably represents the 2‐m air temperature trends across the 1940–2022 (83 years) period at seasonal and annual time scales. We compare ERA5 temperatures with an observation‐based temperature reconstruction for Antarctica (RECON) that has monthly resolution for 1958–2022, the period of reliable observational availability. Results for individual stations are also examined. ERA5 anomalously warms Antarctica in relation RECON especially for the period prior to 1979 when satellite observations over the Southern Ocean were sparse. Trend hotspots that are shown to be artifacts are found at three locations and are present until today. The results demonstrate that ERA5 temperature trends can be questionable even today, but variability is well captured after 1979. Plain Language Summary: Reanalyzes are especially useful for describing and understanding the climate of regions where observations are few and far between. Reanalyzes are not actual conditions but approximations that have strengths as well as weaknesses. A continuing reanalysis challenge for higher latitudes of the Southern Hemisphere that has caused many previous artifacts is the transition from few satellite observations over the Southern Ocean prior to 1979 to the relative abundance since. Here we examine the 2‐m air temperature from the latest global reanalysis from ECMWF for Antarctica and show that it is still challenged by the 1979 transition. ERA5 warms Antarctica much too rapidly especially prior to 1979 and contains artificial trend hotspots at three locations right up to the present. ERA5 cannot be used for Antarctic temperature climate change applications prior to 1979 but can be applied for this purpose after 1979 with appropriate caution. Key Points: ERA5 air temperatures have spurious trends for most regions of Antarctica prior to 1979Artificial trend hotspots are present at three low elevation sites until the presentERA5 cannot be used for temperature climate change studies over Antarctica earlier than 1979 but can be selectively applied post 1979 [ABSTRACT FROM AUTHOR]

Wildfire is a crucial factor in influencing the earth system. Wildfire activities in the Arctic‐boreal region have received increasing attention particularly with increasing frequency and intensity under rapid climate warming in recent years. In this study, the historical simulation and future projection of the Arctic‐boreal fire carbon emissions and associated surface climate conditions (surface air temperature and precipitation) are examined using 17 CMIP6 Earth System Models. For the historical period, more than half (11 out of 17) of the models underestimate ∼40% of the observed annual mean fire carbon emissions in the Arctic‐boreal region (0.20 PgC/yr) due to a wetter bias in the Arctic‐boreal regions. Spatially, there is common underestimation of the fire centers in the eastern part of Eurasian Continent and overestimation of that in Europe. With respect to the model spread, it mainly shows large spread for fire carbon emissions (surface air temperature) in Europe (high‐latitudes). For the future projection, the fire carbon emissions in the Arctic‐boreal region is projected to exceed 100% (0.5 PgC/yr until the end of the 21st century compared with ∼0.2 PgC/yr at present). The projected precipitation and temperature in the Arctic‐boreal region land also show an upward trend during the 21st century (∼31% for annual mean precipitation and ∼10°C for surface air temperature). There are considerable bias and intra‐model spread among different models in both historical simulation and future projection. Plain Language Summary: Warming in the Arctic receives much attentions since it has been warming much faster than in the rest of the world, known as Arctic amplification. Along with rising temperature the climate system also changes substantially, for example, rapid retreating of the Arctic sea ice and more boreal fires. In this study, the historical simulation and future projection of the Arctic‐boreal fire carbon emissions and associated surface climate conditions (surface air temperature, precipitation) are examined using 17 state‐of‐the‐art Earth System Models in which fire carbon emissions variables are available. We found that more than half (11 out of 17) of the models underestimate ∼40% of the observed annual mean fire carbon emissions in the Arctic‐boreal region (0.20 PgC/yr) due to a wetter bias in the Arctic‐boreal regions. There is common underestimation of the fire centers in the eastern part of the Eurasian continent and overestimation of that in Europe. For future projection, the fire carbon emissions in the Arctic‐boreal region is projected to exceed 100% (0.5 PgC/yr until the end of the 21st century compared with ∼0.2 PgC/yr at present), along with projected increase in precipitation and temperature. Although all models show upward trend, the spread among models are large. Key Points: More than half (11 out of 17) of the models underestimate ∼40% of the observed annual mean fire carbon emissions in the Arctic‐boreal regionThere is common underestimation of the fire centers in the eastern part of the Eurasian continent and overestimation of that in EuropeFire carbon emissions in Arctic‐boreal region is projected to exceed 100% along with projected increase in precipitation and temperature [ABSTRACT FROM AUTHOR]

Under global warming, the convective heating over the western Pacific (WP) has exhibited a significantly intensifying trend during the boreal spring, while the surface air temperatures in the Middle East (ME) have increased more rapidly than those in other tropical regions. Are these climate phenomena of the two regions physically connected? If yes, what are the responsible dynamical mechanisms involved? Utilizing the ERA5 reanalysis data and model simulations, this study reveals a significant seesaw variation in the convection and temperature trends between WP and ME. When convective heating intensifies over the WP, the ME tends to be drier and hotter during the spring, and vice versa. A further investigation indicates that the enhanced WP convective heating can induce anticyclonic circulation anomalies in the upper and middle troposphere over the Iranian and Tibetan plateaus. These anomalous high pressures extend westward, exhibiting a barotropic structure, which leads to stronger sinking motions, reduced cloud cover, and increased surface solar radiation over the ME. Consequently, these conditions result in drier and hotter soils and an increase in heatwave days in the ME. This study provides useful information for enhancing our understanding of the role of tropical WP climate change in influencing the upstream climate conditions with a focus on the ME. Plain Language Summary: Under global warming, the western Pacific (WP) has experienced a significant increase in convective heating during the spring, while the Middle East (ME) is seeing a faster rise in surface temperatures compared to other tropical regions. This study investigates whether these climate changes in WP and ME are interconnected and what mechanisms may be involved. The results show that when convective heating intensifies over the WP, the ME tends to become drier and hotter in the spring. The findings suggest that increased heating over the WP can lead to anomalous high pressures over the Iranian and Tibetan plateaus, which result in reduced precipitation, decreased cloud cover, and increased solar radiation, causing higher temperatures in the ME. This study enhances our understanding of how climate changes in the tropical WP can influence weather and climate conditions in the ME. Key Points: The convection in the western Pacific (WP) has been intensifying during spring in 1979–2022Surface air temperatures have been rising faster in the Middle East (ME) than in other tropical regionsThe intensified WP convection likely contributes to the increase in heatwave days over the ME [ABSTRACT FROM AUTHOR]

Compound hazards involving tropical cyclones and extreme heat ("TC‐heat") have rarely been examined in prior research. Peripheral subsidence associated with cyclones can warm an area to varying degrees, depending on the cyclone's strength and position. Meanwhile, the peripheral airflow also overwhelmed the land‐sea breeze circulation system in coastal cities and favored downwind urbanized heat advection on the Southern China coastline. Here, we systematically applied ERA5 global reanalysis data, local surface‐level observations, MODIS‐based land‐cover data and HYSPLIT backward trajectories to evaluate how the position of distant TCs may divert the monsoon system and foster the surface heat advection from upwind urban agglomerate amplifying air temperature in downwind coastline. The analysis suggests when a distant TC is situated in a favorable area (the vicinity of Taiwan and Luzon Strait) at roughly 500–1,250 km to the east of Hong Kong, it forms a unique meteorological condition which allows the surface heat transport from the Greater Bay Area to Hong Kong, reflecting that regional build‐up of heat could be an important mechanism for producing local heat extremes. Plain Language Summary: Rapid urbanization and global climate change bring us new hazards through compound extreme weather events in urban society. Tropical cyclones (TC) are known to bring violent wind and heavy rain upon arrival, while in distant they can also send very hot weather conditions (called TC‐heat events) to regions under its subsidence airflow. This study shows the combined effect of heat from upwind urban areas in coincidence with the TC‐induced subsidence could bring even higher temperatures to the downstream cities like Hong Kong. Comprehensive analysis with global climate data, local weather observations, and backward simulation models were used to further understand how the location of TC may adverse the wind circulation patterns in inland areas and contribute to a larger extreme heat threat to the coastal cities. This can facilitate the early forecast and warning for the potential occurrence of such TC‐heat compound hazard, potentially benefitting public preparedness and response in combating extreme heat and cyclone influences. Key Points: High temperature events occur when distant Tropical Cyclone (DistTC) located at 500–1,250 km from Hong KongSurface heat can be built‐up in inland China cities, transport to Hong Kong as downwind footprint and contribute to the temperature enhancementProbability of high temperature events with DistTC is 15% higher than the normal summer days in Hong Kong [ABSTRACT FROM AUTHOR]

Arctic amplification (AA), characterized by a more rapid surface air temperature (SAT) warming in the Arctic than the global average, is a major feature of global climate warming. Various metrics have been used to quantify AA based on SAT anomalies, trends, or variability, and they can yield quite different conclusions regarding the magnitude and temporal patterns of AA. This study examines and compares various AA metrics for their temporal consistency in the region north of 70°N from the early twentieth to the early 21st century using observational data and reanalysis products. We also quantify contributions of different radiative feedback mechanisms to AA based on short‐term climate variability in reanalysis and model data using the Kernel‐Gregory approach. Albedo and lapse rate feedbacks are positive and comparable, with albedo feedback being the leading contributor for all AA metrics. The net cloud feedback, which has large uncertainties, depends strongly on the data sets and AA metrics used. By quantifying the influence of internal variability on AA and related feedbacks based on global climate model ensemble simulations, we find that water vapor and cloud feedbacks are most heavily affected by internal variability. Plain Language Summary: The Arctic has been observed to warm at a faster pace than the rest of the world, especially over the recent few decades. This phenomenon is known as Arctic amplification (AA), which has connections with different components of the Earth's climate system. Various metrics are used in the science community to measure AA in different data sets and to assess the performance of climate models in reproducing the observed history of AA. In this study, we apply a collection of AA metrics from the literature to the same historical data sets, based on observations and climate model experiments, to identify differences/similarities and pros/cons of these metrics. We also study how radiatively active processes in the climate system, like changes in snow/ice surface reflectivity (albedo), air temperature changes with height (lapse rate), humidity increase, and cloud changes, can in turn amplify (positive feedback) or dampen (negative feedback) this overall Arctic warming. Our study shows that changes in the Arctic surface albedo and lapse rate are the main drivers of AA. We also find that natural climate variations can greatly influence Arctic warming in climate models and their ability to reproduce the observed AA by affecting regional water vapor and cloud patterns. Key Points: Arctic amplification is quantified by applying various metrics to observational data, reanalysis products, and model simulations.Radiative feedback analysis shows that albedo and lapse rate feedbacks are the main contributors to Arctic amplification for all metrics.Water vapor and cloud feedbacks are most heavily influenced by internal variability. [ABSTRACT FROM AUTHOR]

The postharvest lighting environment is a main factor that influences quality preservation for harvested biomass. The objective of this study was to evaluate postharvest changes in bioactive compounds of lettuce with different storage light spectra. The effects of green LEDs with peaks at 500 nm and 530 nm, white LEDs (400–700 nm), and dark storage were evaluated, where light intensity (10 μmol m-2 s-1) and photoperiod (12 h per day) were constant with air temperature at 5°C over the 14 d treatment period. Lettuce stored with 500 nm and 530 nm green LEDs exhibited 1474.5% and 1451.8% (approximately 15.7 and 15.5 times) higher antioxidant activity, respectively, compared to dark storage. Significant improvements in total phenolic content, and 67.5% and 64.8% increases in total soluble solids with 530 nm and 500 nm green LEDs over dark storage were discerned. Exposure to 530 nm green LEDs led to 128.2% (approximately 2.28 times) higher anthocyanin content, a 26.2% increase in carotenoids, and a 95% rise in flavonoid content compared to dark storage. Increases of 26.4% and 16.0% in chlorophyll a content in lettuce stored under 500 nm and 530 nm green LEDs, respectively, and 65.6% and 46.6% rises in the Chlorophyll a/b ratio were observed. Compared to dark storage, green LEDs (500 nm) resulted in a 13.5% higher total chlorophyll content. Findings underscore the positive impact of green LEDs on the nutritional quality of lettuce, providing insight for postharvest practices. [ABSTRACT FROM AUTHOR]

Cave air temperatures in four caves in the European Alps show statistically significant warming trends of about 0.2 °C per decade over the last two decades (2000–2020). These trends are about half as large as those observed outside and are characterized by a remarkable spatial and temporal consistency. The investigated caves represent different types in terms of their ventilation regime and one of them also hosts perennial ice. Key observation sites are located in cave sections where the temporal variability of air temperature is strongly attenuated compared to outside conditions and data from different cave sections show that the main results are valid for large parts of the investigated caves. Continued warming will lead to broad changes in alpine cave environments, including changes in strength and direction of air flow in caves, karst hydrology and subsurface ecosystems. The observed subsurface warming has a particular strong effect on the long-term preservation of perennial ice present in some of these caves. This is shown for an ice cave in the Austrian Alps, where enhanced melt of ice correlates with the observed warming. This cave (and similar ones) will not be able to hold perennial ice beyond the next decade. [ABSTRACT FROM AUTHOR]

Due to their significant influence on large‐scale atmospheric circulation and climate anomalies, the variability of Arctic sea ice and Eurasian snow cover during late autumn and their combined effects have garnered increasing attention. This study aims to investigate the physical mechanism underlying the covariation among the Barents‐Kara Seas (BKS) sea ice concentration (SIC), Eurasian snow cover extent (SCE) and the ensuing winter Eurasian surface air temperature (SAT). The statistics results of singular value decomposition suggest a significant linkage between the decreased BKS SIC, zonal "negative–positive" dipole SCE anomalies over Eurasia in November and cold Eurasian SAT in January–February (JF). Observational diagnosis analyses about the meridional moisture, heat transport and surface heat flux demonstrate that subpolar Eurasian anticyclonic circulation plays a crucial role in connecting the predominant modes of SIC and SCE. Furthermore, the BKS SIC and Eurasian SCE anomalies can jointly excite upward‐propagating planetary waves into the stratosphere, while simultaneously reducing the subpolar meridional temperature gradient. This results in westerly wind deceleration and favours the continuous planetary wave propagation. Consequently, the stratospheric polar vortex is significantly weakened, along with negative Northern Annular Mode anomalies propagating downward from the stratosphere to troposphere. Negative‐phase Arctic Oscillation anomalies correspondingly develop during JF, resulting in widespread cold anomalies over the Eurasian continent. These results are further confirmed by numerical sensitivity experiments from the Community Atmosphere Model forced by the above mentioned SIC and SCE anomalies. The empirical hindcast model analyses further suggest that the prediction skill of JF Eurasian SAT is enhanced when both the November BKS SIC and Eurasian SCE signals are considered. [ABSTRACT FROM AUTHOR]

The atmospheric activity on Kalimantan Island (KI) is important for regulating regional weather and climate. This study investigates the effect of autumn soil moisture over KI on following winter precipitation over southern China (SC) during 1968–2014. The results show that the autumn soil moisture over the KI has a significant negative correlation with subsequent winter precipitation over SC. The correlation remains statistically significant when using partial correlation to filter out the concurrent influences of El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) signals. The soil moisture anomalies over KI, which initiate in the autumn and persist into the winter, lead to changes in local thermal conditions and atmospheric temperature. Negative soil moisture anomalies over KI will result in positive heating anomalies of the atmosphere above the land surface. This atmospheric heating causes ascending motion, which creates a semi‐closed vertical circulation from KI to the tropical northwest Pacific. This vertical circulation would strengthen the northwest Pacific anticyclone and weaken the East Asian winter monsoon (EAWM). Consequently, southwesterly water vapour flux prevails in the SC as well as the South China Sea (SCS), facilitating the transportation of more water vapour into the SC. Simultaneously, water vapour convergence in the SC. Collectively, these contribute to an addition of precipitation over SC. [ABSTRACT FROM AUTHOR]

In recent decades, India has witnessed an increase in the intensity, frequency, and spread of extreme weather events. The widespread increase in extreme precipitation over the Western Coast of India is a matter of great concern. The factors contributing to such devastating extreme precipitation remain unclear due to the variability present in meteorological and oceanic variables and associated large‐scale circulations. Using reanalysis and observed datasets, we attempted to identify a combination of dynamic, thermodynamic, and cloud microphysics processes contributing to the anomalous precipitation from August 1 to 10, 2019 against its climatology. Our key findings highlight the crucial role of warm sea surface temperatures (anomaly >1.4°C), outgoing longwave radiation (anomaly <−50 W·m−2), and atmospheric temperature (anomaly over the ocean is >1.6°C) in enhancing the moisture‐holding capacity of the atmosphere by almost 10%. This elevated moisture, propelled by intensified low‐level winds (anomalies exceeding 4 m·s−1), leads to a shift from ocean to land. Notably, we observe that vertical updrafts (anomalies >−0.4 m·s−1) contribute to increased atmospheric instability and moisture convergence. The presence of an ample amount of cloud hydrometeors, with anomalies surpassing 2.5 × 10−4 kg·kg−1, establishes conditions conducive to sustained intense precipitation. Our findings deepen our understanding of the complex relationships between ocean and atmospheric dynamics, and wind patterns, and emphasize their pivotal influence on regional weather patterns and land surface hydrology. [ABSTRACT FROM AUTHOR]

Under global warming, heatwaves (HWs) are exerting increasing impacts on human life. In order to explore the thermal sensation of HWs under the combined influence of air temperature, humidity, radiation and wind speed, this study utilized the hourly Universal Thermal Climate Index (UTCI) data from the ECMWF Reanalysis v5 (ERA5) to define daytime, night‐time and compound HWs, and then comparatively analysed their occurrences in China during 1981–2020. Results revealed that daytime HWs affect the majority of regions in China with the exception of the Tibetan Plateau, while both night‐time and compound HWs mainly strike the Yangtze River Basin and the Guangdong–Guangxi region in southeastern China. Additionally, it is noteworthy that a substantial portion of regions experiencing night‐time HWs also encounter compound HWs. The frequency and intensity of all three types of HWs show increasing trends generally in regions where HWs occur. The spatial coverage of HWs grows at rates of 8.05%/10a, 2.11%/10a and 1.62%/10a for the daytime, night‐time and compound types, respectively. For each summer month, the spatial coverage of daytime HWs notably surpasses that of night‐time and compound HWs. Further classifying HWs with intensity, it is found that the spatial coverage of both moderate and severe HW events exhibits discernible rising trends across all three types of HWs. Furthermore, regions with higher HW frequencies are more likely to experience severe HWs as well as record‐breaking ones. Additionally, the spatial coverage of daytime, night‐time and compound record‐breaking HWs is expanding. [ABSTRACT FROM AUTHOR]

Snow is particularly impacted by climate change and therefore there is an urgent need to understand the temporal and spatial variability of depth of snowfall (HN) trends. However, the analysis of historical HN observations on large‐scale areas is often impeded by lack of continuous long‐term time series availability. This study investigates HN trends using observed time series spanning the period 1920–2020 from 46 sites in the Alps at different elevations. To discern patterns and variations in HN over the years, our analysis focuses also on key parameters such as precipitation (P), mean air temperature (TMEAN), and large‐scale synoptic descriptors, that is, the North Atlantic Oscillation (NAO), Arctic Oscillation (AO) and Atlantic Multidecadal Oscillation (AMO) indices. Our findings reveal that in the last 100 years and below 2000 m a.s.l., despite a slight increase in winter precipitation, there was a decrease in HN over the Alps, especially for southern and low‐elevation sites. The South‐West and South‐East regions experienced an average loss of 4.9 and 3.8%/decade, respectively. A smaller relative loss was found in the Northern region (2.3%/decade). The negative HN trends can be mainly explained by an increase of TMEAN by 0.15°C/decade. Most of the decrease in HN occurred mainly between 1980 and 2020, as a result of a more pronounced increase in TMEAN. This is also confirmed by the change of the running correlation between HN and TMEAN, NAO, AO over time, which until 1980 were not correlated at all, while the correlation increased in later years. This suggests that in more recent years favourable combinations of temperature, precipitation, and atmospheric pattern have become more crucial for snowfall to occur. On the other hand, no correlation was found with the AMO index. [ABSTRACT FROM AUTHOR]

Since the land 2 m air temperature from European Centre for Medium-Range Weather Forecasts Reanalysis 5 (ERA5-land) is vulnerable to interference by regional climate characteristics and local topography, how to objectively and accurately evaluate its accuracy and then establish a refined model is the key to improve its multifaceted and deep-level applications. This study proposed a systematic and complete refinement method for ERA5-land air temperature based on the densely distributed weather stations in Shandong Province in eastern China, including the compensation of elevation matching bias (EMB) caused by ASTER GDEM and the overall refinement using the remove-and-restore model (RRM). Taking the hottest July and the coldest December in this area, surface air temperature, atmospheric weighted mean temperature (Tm) and GNSS precipitable water vapor (PWV) were used to verify the feasibility of this method. The results show that: (1) Whether the temperature is high in July or low in December, the accuracy can be improved by about 42.2 % when the refinement method was used. Especially for high altitude areas (the summit of Mount Tai, 1553 m above sea level), the accuracy can be improved by 74.5 %. (2) In contrast to only the temperature lapse rate (TLR) correction, the average root mean square (RMS) can be reduced by 7.4 % and 60.4 % in July and 7.0 % and 59.5 % in December for the met stations less than 150 m in altitude and the peak station of Mount Tai, respectively, when the new method was used. (3) Compared with the Tm and PWV computed by interpolated temperature without any correction, the accuracy of Tm can be improved by 31.2 % and 34.1 % in July and December for weather station in the altitude of 100 ∼ 350 m after the TLR correction, EMB compensation and RRM refinement successively. Meanwhile, the accuracy of PWV can be improved by 47.8 % in July and 42.0 % in December, respectively, and especially for PWV high-value moments. Besides, after correction by RRM, both Tm and PWV in low altitude areas achieve at least 20 % accuracy improvement. In summary, the systematic and complete refinement method proposed in this study are important to significantly improve the ERA5-land 2 m temperature availability and GNSS PWV accuracy, and the compensation of EMB is mainly effective for high altitude areas. [ABSTRACT FROM AUTHOR]

Zeolite honeycomb monoliths (ZHMs) as key adsorbents or catalysts are widely applied in industries, for which, however, the popularization is limited by its low production efficiency due to the long and careful drying process of the fragile ZHMs green body. Here we address this challenge by developing a microwave drying strategy coupled with convective air and steam. The individual microwave, microwave-air, and microwave-air-steam drying characteristics on the honeycomb and slab monoliths of 13X zeolite were systematically studied, and the drying quality-microwave power/air temperature/humidity relationship was correlated. The results showed that microwave achieves rapid dehydration of ZHMs, eliminating 29.94 % relative mass of water within only 660 s. However, the uncontrollable microwave adsorbing inhomogeneity and thermal accumulation over the hydrophilic ZHM resulted in overburning, cracking and deformation issues. Introducing convective air at room temperature eliminates overburning and cracking phenomena, and after coupled with 110 g/m3 steam, the irregular deformation of ZHMs was further mitigated (shrinkage rate reduced from 2.10 % to 1.11 %) with even increased drying efficiency by 4.47 %. The advantageous mechanism of microwave-air-steam coupling drying was revealed as the combined effect of the heat and mass transfer through the honeycomb hole enhanced by convective air and the heating and dehydration homogeneity improved by uniform microwave absorbing on surface-condensable steam. The efficacy of the optimized drying strategy was demonstrated by significantly shortened time for scale-up production of 1 m3 ZHMs from nearly 1 month to 2 days. This work affords new insights for improving production efficiency of high-quality ZHMs and presents microwave-air-steam drying process as a platform to advancing structured material preparation. [ABSTRACT FROM AUTHOR]

Oleaginous green microalgae are often mentioned in algae-based biodiesel industry, but most of them belong to specific genus (Chlorella, Scenedesmus, Botryococcus and Desmodesmus). Thus, the microalgal germplasm resources for biodiesel production are limited. Mutagenesis is regarded as an important technology for expanding germplasm resources. The main purpose of this study is to screen microalgae strains with high carbon dioxide tolerance and high lipid content from mutants derived from indigenous non-oleaginous green microalgae species—Ulothrix SDJZ-17. Two mutants with high CO2 tolerance and high lipid content genetic stability were obtained from the mutants by high-throughput screening, named Ulothrix SDJZ-17-A20 and Ulothrix SDJZ-17-A23. In order to evaluate the potential of CO2 fixation and biofuel production, A20 and A23 were cultured under air and 15% CO2 (v/v) conditions, and their wild-type strains (WT) were used as controls. Under the condition of high CO2 concentration, the growth performance and lipid production capacity of mutant strains A20 and A23 were not only significantly better than those of wild strains, but also better than those of their own cultured under air conditions. Among them, A23 obtained the highest LCE (light conversion efficiency) (14.79%), Fv/Fm (maximal photochemical efficiency of photosystem II) (71.04%) and biomass productivity (81.26 mg L−1 d−1), while A20 obtained the highest lipid content (22.45%). Both mutants can be used as candidate strains for CO2 fixation and biofuel production. By ARTP (atmospheric and room temperature plasma) mutagenesis with high-throughput screening, the mutants with higher CO2 tolerance, photosynthetic efficiency and lipid productivity can be obtained, even if they are derived from non-oleaginous microalgae, which is of great significance for enriching the energy microalgae germplasm bank, alleviating the global warming and energy crisis. [ABSTRACT FROM AUTHOR]

Climate change has caused extreme weather events, including frequent summer heat waves. We examined how the effects of high air temperatures on mortality have changed between the two study periods (1991–1995 and 2015–2019), including 1994 and 2018, the worst heat wave years in the meteorological history of South Korea. Temperature data from the Korea Meteorological Administration and mortality data from Statistics Korea were used in this study. We used distributed lag nonlinear models to estimate the cumulative relative risks (CRRs) to determine the association between daily maximum temperature in summer (June to September) and mortality. CRRs were estimated for each province and pooled using a random-effects meta-analysis for all provinces. Maximum temperature and annual average days in heat wave were 37.7°C and 11.8 in 1991–1995 and 38.3°C and 18.8 in 2015–2019. The slope of the CRR for mortality increases with increasing temperature and has been steeper in the past than in recent years and steeper in those over 65 than in those under 65. Excess mortality has recently declined compared with that in the past. The impact of high summer temperatures on mortality changed between the two periods, suggesting improved population resilience. [ABSTRACT FROM AUTHOR]

This paper presents a high-resolution gridded dataset of daily minimum (TN), mean (TG) and maximum (TX) near-surface air temperatures over Poland, covering the period from 1951 to 2020, with a spatial resolution of 1 km2. PL1GD-T dataset was developed using radial basis functions (RBFs) applied to quality-controlled observations from ground weather stations from the Institute of Meteorology and Water Management – National Research Institute. Cross-validation methods evaluated the gridding procedure on a monthly basis. The linear RBF was employed by hold-out cross-validation (HO-CV) as the most suitable for the gridding procedure among other RBFs. The leave-one-out cross-validation (LOO-CV) was performed to ensure the ability to reproduce the original characteristics variability. The values of the scores averaged over all stations for individual months are in range 0.3–0.2, 0.3–0.2, 0.1–0.2 for the bias, in range 1,23–1,46, 0.69–0.92, 0.84–0.99 the root-mean-squared difference (RMSD) and in range 0.91–0.97, 0.98–0.99, 0.98–0.99 for the correlation for TN, TG and TX, respectively. The RSMD is clearly altitude dependent, increasing from low-land to mountainous regions. The dataset's scope and resolution allowed robust estimation of local climate variability characteristics and observed trends. The availability of high-resolution datasets in both spatial and temporal contexts is essential for climate change impact analysis on a smaller scale. This new dataset provides a quality-validated, high-resolution, and open-access dataset that could be utilised by society, administrative bodies, or research institutions for further analysis. The dataset is publicly available from the repository of the Institute of Meteorology and Water Management – National Research Institute under https://doi.org/10.26491/imgw%5frepo/PL1GD-T (Jaczewski et al., 2024). [ABSTRACT FROM AUTHOR]

An updated near-surface temperature reconstruction for the Antarctic continent is presented for 1958 to 2022 (65 years) as monthly anomalies relative to 1981–2010 (RECON). It is based on monthly mean 2-m temperatures at 15 fixed stations that are spatially extrapolated to the entire continent using weights derived from the European Centre for Medium-Range Weather Forecasts 5th generation reanalysis (ERA5). Infilling of the fixed station records are performed where necessary to yield complete time series for 1958–2022. Variability and trends are tested at independent stations that have much shorter periods of record. RECON is designed for Antarctic climate variability and change applications for large spatial scales and extended time scales. [ABSTRACT FROM AUTHOR]