How useful are the lake surface temperature estimates from a geostationary satellite (Himawari-8) to detect seasonal and diurnal changes?

Abstract

The current geostationary satellite images have a time resolution of minutes. However, it is not clear how useful they are for detecting diurnal and seasonal changes. We have tested this by comparing lake surface temperatures LSTs from Himawari-8 AHI images with in situ measurements in Lake Kasumigaura, Japan for one year. LST products of the Sentinel-3 satellites were also compared. We found that instantaneous LSTs can be estimated with an RMSE of 0.6°C. A large amount of data (N = 10 2 -10 3 ) is available for each month, but N differs greatly in the range of 216 -2771. A good agreement (RMSE of 0.9°C) was found between monthly mean LSTs from Himawari-8 and in-situ measurements and is better than the RMSE of 1.2-1.7°C found for the Sentinel-3 LST products. The diurnal change detection was found more difficult due to insufficient data numbers around noon. Practical remedies for this issue are suggested.