Total Cloud Cover in Xinjiang Uygur Autonomous Region, Northwest China: A Comparison of ERA5 and ISCCP With FY4A

Cloud is an important factor affecting climate change, playing a crucial role in controlling the Earth’s energy and water cycle. In this study, total cloud cover (TCC) from the fifth‐generation atmospheric reanalysis of the European Centre for Medium‐Range Weather Forecasts (ERA5) and the International Satellite Cloud Climate Project H‐series (ISCCP) were compared with those from the Advanced Geosynchronous Radiation Imager (AGRI) aboard Fengyun4A (FY4A) and ground observations (OBS), revealing the spatiotemporal distribution characteristics of TCC in Xinjiang Uygur Autonomous Region (Xinjiang), northwest China. The findings indicate that the interannual fluctuations in the annual mean TCC from OBS in Xinjiang exhibit no discernible trend, while those based on ERA5 and ISCCP demonstrate a decline. The TCC from FY4A and ISCCP shows a distribution pattern of high in the south and low in the north, whereas the opposite is true for that from OBS and ERA5. For all ground observation stations, the mean values of TCC from ERA5, OBS, FY4A, and ISCCP are 45.9%, 49.1%, 49.5%, and 63.0%, respectively. At the majority of ground observation stations (with the exception of those in southwest Xinjiang), the discrepancy between the TCCs from FY4A and those from OBS (ERA5) is less than 10%. However, at the majority of stations in north Xinjiang, the TCCs from ISCCP are more than 10% larger than those from FY4A. Furthermore, there are discernible discrepancies in the frequency of occurrence and spatial distribution of distinct cloud types. The findings of this study serve to enhance the comprehension of the spatiotemporal characteristics of TCC in Xinjiang, northwest China, thereby facilitating the more effective application of FY4A in arid regions.