太陽輻射為地球能量的主要來源，雲霧變動特性顯著的影響到達地面的太陽輻射量。此外，雲霧為地表與大氣能量、水及碳交換過程的重要影響因子之一。本研究藉由2003-2021年的MODIS雲產品資料探討全島雲遮蔽的長期、季節與日夜空間變動特性，結果顯示中雲及低雲的平均雲頂高度分別為2,285m及4,539m，為影響臺灣較大的兩個雲族。此外，下午的雲遮蔽率高於其他三個觀測時點，東部三個地理氣候分區的雲遮蔽率明顯高於西部三區，以臺灣的東北區的雲遮蔽率最高，東南區其次。

Solar radiation is the major energy source of the Earth. The amount of solar radiation reaching the ground is significantly affected by the characteristics of clouds. In addition, clouds are one of the most important factors for the interaction of energy, water, and carbon between the surface and the atmosphere. This study explored the long-term, seasonal, and diurnal spatial variability of island-wide cloud cover in Taiwan based on MODIS cloud product data from 2003 to 2021. The results showed that the average cloud top heights of the middle and low clouds were 2,285 m and 4,539 m, respectively, which are the two major cloud classes affecting Taiwan. Moreover, the cloud cover rate in the afternoon was higher than that of the other three observation periods. The cloud cover rate of the three geographical climatic regions in the east was significantly higher than that in the three western regions. The northeast region of Taiwan has the highest cloud shadowing rate, followed by the southeast region.