Spatio-temporal Evolution Characteristics and Driving Forces of Winter Urban Heat Island:A Case Study of Rapid Urbanization Area of Fuzhou City,China

Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving forces.Taking the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to 2021.Combing comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically analyzed.The results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the suburbs.There was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space scale.The LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated lands.Vegetation and water bodies had a significant mitigation effect on UHI,especially in the micro-scale.The winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading role.This research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development.

Relations between Low-Frequency Modes of Climate Variability and Air-Sea Heat Flux at the Mediterranean Interface

The main objective of this work is to examine statistical causality relationships between low-frequency modes of climate variability and winter （December to February） anomaly of net heat flux at the Mediterranean air-sea interface. The introduction of the concept of Granger causality allowed us to examine the influence of these climates indices on the net heat flux anomaly and to select Mediterranean surface regions that really influenced by each index. Results show that the winter anomaly of the net heat flux in the Algerian basin south and the gulf of Lion is mainly caused by the Arctic Oscillation. El Nifio-Southern Oscillation influences much more the Algerian basin north and the northern lonian Sea. The Quasi-Biennial Oscillation affects only the Alboran and the Tyrrhenian Seas. But the Adriatic and Levantine basin are impacted by any climate index. They also show that these climate indices can increase explained variance in winter variations of air-sea net heat flux by 10% to 15%, with a lag of three seasons. These relationships are less persistent and spatially limited.

CFD Simulations of Wind Effect on Net Solar Heat Gain of South Walls with Internal Insulation

Computational fluid dynamics( CFD) techniques are used to investigate effects of both wind direction and wind speed on net solar heat gain of south wall with internal insulation in winter.Results show that wind effect has a significant influence on the net solar heat gain,where the impact of wind direction is stronger than that of wind speed. For regions in lower reaches of the Yangtze River,difference of their average net solar heat gains( NSHGS) is about 20% due to various wind speeds and wind directions.Buildings in districts with a dominant wind direction of north achieve the highest solar energy utilization.

Winter Sports Heat Up

This winter, most resions in China have seen snow, and even south China, where snow is rare, has been hit by blizzards. While causing inconvenience to travelers, snow is fueling the country＇s winter sports industry.

Responsible Behavior of Irresponsible Companies:Air Pollution and Charitable Donations of Polluting Companies

The relationship between air pollution and charitable donations of companies has received little attention from academia.To make up for this defect,we use a regression discontinuity design based on the spatial discontinuity in air pollution created by China's winter heating policy in the north of Qinling Mountains–Huai River line to examine whether severe air pollution may cause polluting companies to make charitable donations.Our results consistently show that air pollution has a positive impact on the donations of polluting companies,regardless of whether the absolute donations,the relative donations,or the willingness to donate are used to measure donations.A series of robustness tests confirm that this relationship is causal.Furthermore,we find that under severe air pollution,the motivations of polluting companies to implement donation behaviors are to decrease the probability of environmental penalties,reduce environmental pollution costs,and decrease the extent to which air pollution affects company reputations.

Thermal performance and comfort assessment of U-shape and helical shape earth-air heat exchanger in India

Earth Air Tunnel Heat Exchanger(EATHE)systems are not so much popular in India because of restricted acces-sibility of ground space in majority of residential and commercial sector.In the present article,thermal perfor-mance of newly designed helical shaped EATHE system has been compared with conventional U-shaped EATHE system by keeping similar geometrical and operational configuration for the summer(April-June)and winter(December-February),respectively.In this regard,therefore,numerical model of both EATHE systems have been designed and experimentally validated.The thermal performance of both EATHE systems has been compared in terms of outlet air temperature and effectiveness.The present numerical study suggested that the newly designed helical EATHE system exhibits better thermal performance with lower ground requirement as compared to con-ventional U-shaped EATHE system.To evaluate the thermal comfort potential of EATHE system in office buildings of India,composite climate specific adaptive thermal comfort boundaries has been used.The detailed thermal performance behaviour of the EATHE system suggests that an additional 80%of the time;ambient air condi-tions became thermally comfortable during peak summer season.In addition,analysis of the results revealed that EATHE system has more potential during heating operation mode to maintain indoor comfort in winter season of composite climate in India.