Enhancement Of Surface Urban Heat Island By Atmospheric Temperature Feedback

As the region with the most drastic changes in LUCC around the world,the city will accommodate 70% of the world's population in the future.Such a rapid urbanization process is bound to have a serious impact on the global climate.Surface urban heat island(SUHI)is an important climatic result of the drastic changes in LUCC during the urbanization process.Its formation aggravates the air pollution in the city and poses a serious threat to the health of the residents.The atmospheric temperature feedback process caused by the radiation and turbulent heat transfer between the surface and air is an inevitable link in the process of urban surface warming after the disturbance of LUCC,which plays a crucial role in the formation of SUHI.Therefore,in-depth study and quantification of the enhancement effect of atmospheric temperature feedback on SUHI is of great significance for the analysis of the process mechanism and main control factors of the formation of SUHI,and it is of great significance to predict future climate change and propose mitigation measures of SUHI.In this paper,we modified the linear decomposition method of surface Temperature--Two Resistance Mechanism(TRM),and constructed the two-resistance mechanism with atmospheric temperature feedback method(ATF-TRM).Then,ATFTRM was used to isolate and quantify the enhancement of Atmospheric Temperature Feedback to SUHI.Atmospheric Temperature Feedback Intensity was also defined to characterize the enhancement effect of Atmospheric Temperature Feedback on SUHI.We also studied the spatiotemporal characteristics and influencing factors of Atmospheric Temperature Feedback Intensity in 328 cities in China.The results showed that ATF-TRM significantly improved the estimation accuracy of Surface Urban Heat Island Intensity(SUHII).Atmospheric temperature feedback has a significant enhancement effect on SUHI and is the primary contribution of SUHI.The enhancement of SUHI by atmospheric temperature feedback has obvious spatial and temporal characteristics: the enhancement of SUHI by atmospheric temperature feedback in winter is higher than that in summer;The enhancement effect of atmospheric temperature feedback on SUHI at night was significantly higher than that in daytime.The enhancement effect of atmospheric temperature feedback on SUHI in arid/semi-arid regions was higher than that in sub-humid/humid regions.The enhancement process of SUHI influenced by atmospheric temperature feedback is mainly through two important parameters: surface temperature sensitivity parameters and surface energy disturbance.The surface temperature sensitivity parameters are related to the vegetation growth in the rural background,and the surface energy disturbance caused by atmospheric temperature feedback is related to the temperature difference between urban and rural areas.In the future,we can reduce the sensitive parameters of surface temperature and the air temperature difference between urban and rural areas by adjusting the type of rural land cover and the degree of greening,to achieve the purpose of alleviating the feedback intensity of atmospheric temperature.In this paper,the mechanism of atmospheric temperature feedback-two resistance.method enhances the precision of estimated SUHI on one hand,on the other hand,it can effectively separate and quantify the contribution of atmospheric temperature feedback on the formation of SUHI and reveal the main characteristic of atmospheric temperature feedback contribution amount and the influence factors.It is helpful to deeply analyze the process mechanism and main control factors of SUHI formation and can provide reference for future research on SUHI...