Publications

Xu, RH; Wang, X; Hu, YH; Chen, L; Ren, SL; Cao, GZ; Xian, D; Mogha, ER (2025). Estimation of All-Sky Gridded Diurnal Near-Surface Air Temperatures at Regional Scale From FY-4B Measurements. IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING, 18, 1288-1301.

Abstract
The near-surface air temperature ( T (air) ) is a principal variable describing energy exchange and water circulation between the land surface and the atmospheric environment. The estimation of T (air) by satellite land surface temperature (LST) is challenging due to the variable magnitude of the difference between T (air) and LST in both space and time, as well as the restriction of estimated T (air) to clear-sky conditions because of the penetration of infrared wavelengths. Moreover, the estimation suffers from low temporal resolution and primarily focuses on daily minimum, maximum, and two instantaneous T (air) per day. This study proposes a method for estimating all-sky gridded diurnal T (air) at regional scale from FY-4B/AGRI measurements. The multi-scale geographically weighted regression model was investigated to establish the dynamic relationships between ground station observed T (air) and satellite LST under clear-sky conditions by employing different spatial values for each explanatory variable in localized regressions. A moving window loop based multiple linear regression was employed to establish the relationship between satellite derived clear-sky T (air) and other variables to extrapolate T (air) in cloudy-sky pixels. The results showed that the proposed method captures the trend of T (air) variations well in hourly profiles with R values greater than 0.95. RMSE was 1.75 degrees C, 1.38 degrees C, 1.95 degrees C, and 2.19 degrees C in April, July, October, and January, respectively. The demonstration of heatwave monitoring showed that satellite-estimated T (air) provide an excellent representation of the spatial and temporal evolution of the heatwave.

DOI:
10.1109/JSTARS.2024.3506857

ISSN:
1939-1404