Analysis of Changes in Earth Radiation Budget and Cloud Amount from the Satellite Data and the CMIP5 Model Simulations

To examine the interactions between the Earth radiation budget and cloud changes within the context of climate change, this study analyzes the radiation budget from International Satellites Cloud Climatology Project (ISCCP) products and evaluates the CMIP5 model performance by comparing it to observations. The observed trend of radiation at the top of atmosphere (TOA) and the surface of earth (SRF) from 1984 to 2009 are calculated using FD_TOA and FD_SRF datasets. Globally, the radiation at TOA only changes with latitude. However, the surface radiation has more variations over the 26 year time period. The trends of surface net radiation and mean cloud amount are generated from five available models. Two main focus areas are considered in this research: the continental United Sates and China. The regional trend in the Great Plains is positive while the southwest region shows a negative trend. In China, most areas have a positive local trend but Tibet and the east coast area have decreasing trends. The trend of cloud amount (%) over the 26 year time period is classified based on the frequency of clear-sky and overcast sky. The mean cloud amount shows an increasing trend in U.S. but a decreasing trend in China. This research will help in understanding how the radiation budget and cloud trends impact climate change, and especially, how the regional changes may affect agriculture.