Study On Applicability And Spatio-temporal Change Of HIRS Land Surface Temperature Products In China

Land surface temperature is the result of interaction and energy exchange between land and atmosphere.It is important in numerical research,drought monitoring,climate change and other research fields.Therefore,land surface temperature data with high quality will provide basic data for other related studies.The HIRS land surface temperature product covers the whole world,with a spatial resolution of 0.5degrees and a time resolution of one hour.From 1979 to 2009,it is one of the longest satellite remote sensing LST data.This paper first studies the applicability of the product in China,and then analyzes the spatio-temporal variation of land surface temperature in China based on this product.The main conclusions are as follows:(1)In the Poyang lake basin of China,the HIRS LST product has good agreement with the in-situ observations from aspects of temporal variations,but the product generally underestimates the in-situ observations,mainly due to its underestimation for LST above 35 °C.The product performs the worst in summer and performs best in winter.In addition,the product overestimates the warming trend of LST in summer,and to some extent underestimates the warming trend of LST in autumn.(2)The HIRS LST has good agreement with MODIS LST from aspects of daily variations in most areas of China except the Tibet Plateau.In the area east of 100°E in China,the deviation of HIRS LST from MODIS LST is small.From the analysis based on regional average,it's found that the two sets of data have a good linear relationship in the arid zone,the transition zone,the humid zone and the Tibet Plateau,especially in the arid zone and the Tibet Plateau.(3)In the Chinese region,the multi-year average HIRS LST shows a spatial pattern that gradually increases from northwest to southeast of China,ranging from-10 °C to 25 °C,and shows significant seasonal differences.The HIRS LST shows a significant warming trend in most parts of China,especially in the northeast and northwest regions,the warming rate is over 0.60 °C/10 a.The trend is not significant in the Tibet Plateau,but the Tibet Plateau as a whole shows a more significant warming trend than the arid,transitional and humid regions.Significant warming trends are mainly in spring and winter.Extremely high LST shows a more obvious increase in the area east of 100°E in China from aspects of both frequency and intensity,and the increase is more obvious after entering the 21 th century.