Consistency Assessment Of Surface Temperature Between AIRS And MODIS And Its Temporal And Spatial Variation Mechanism

Land surface temperature(LST)plays a critical role in the water cycle and energy balance at global and regional scales.LST retrieved by remote sensing has been widely applied to environmental monitoring and climate change research.Based on the LST products of AIRS(the Atmospheric Infrared Sounder)and MODIS(the Moderate Resolution Imaging Spectroradiometer)on the Aqua satellite,the reanalysis data ERA5-Land LST and the air temperature data of meteorological stations,this study analyzes the applicability of daytime remotely sensed LST products and its ability to monitor the environment,from three perspectives: the consistency of remotely sensed LST products,the characteristics of temporal and spatial LST changes and its relationship with environmental factors,and the relationship between remotely sensed LST and air temperature.This increases confidence in the use of remote sensing LST to deal with future climate changes.The main research results are as follows:(1)MODIS LST products overall underestimates relative to AIRS LST on the global land,with an overall difference of about 2K.The areas with a big difference of more than 6K between the two data are mainly bare land types under arid climate conditions,such as mountainous regions,plateaus,and desert areas.In most areas except tropical rain forests,their time series correlation coefficients exceed 0.8.The poor consistency in tropical areas suggests that clouds interfere with remote sensing observations.(2)The LST trends of remote sensing and reanalysis are generally consistent in time and space.An upward trend in the annual average LST during 2003–2017 is mainly in the region north of the 45°N latitude,especially in the Asian Russian region.The regression analysis shows that precipitation(P),incoming surface solar radiation(SW?),and incoming surface longwave radiation(LW?)can explain the interannual LST changes in most areas except tropical forests.The changes in LST north of 45°north latitude were mainly influenced by LW?,while P and SW? played a more important role over other regions.Over selected regions,the warming in Asian Russia is closely related to the simultaneously increasingLW? and clouds.Over the southern Amazon,the most apparent LST increase is found in the dry season,primarily affected by decreasing P.In addition,increasing SW? associated with decreasing atmospheric aerosols was another factor found to cause LST increases.(3)Numerical differences in LST and air temperature are closely related to forest coverage.And there is a good consistency of time series between the remotely sensed LST and the daily maximum air temperature from site.The LST trend signal is confirmed by result of air temperature.The trends in LST can catch the signal of deforestation.In addition,results of anomalies temperature show close temporal-spatial relationships of between remotely sensed LST and air temperatures from station under extreme drought events.Therefore,satellite data can provide good supplementary information for monitoring disaster,especially in areas with sparsely distributed meteorological stations.