Analysis on influential factors of solar radiation in the north shore of Taihu Lake, China

By using the 2a solar radiation data of the urban and rural areas in the north shore of Taihu Lake, China, the solar radiation characteristics over the areas was comparatively analyzed. Results showed as follows. (1) Solar radiation in urban areas is more than 13 % lower than that in rural areas. (2) The minimal solar radiation generally occurs in winter, but the maximal one is not necessarily in summer, which is well coincided with Jiangnan Meiyu occurring from mid-June to mid-July. (3) The solar radiation rate decreases with the cloud cover increasing. the solar radiation rate changes little with the cloud cover lower than 50%. while a strong blocking effect on solar radiation appears with the cloud cover more than 50 %. When the sky is sunny or brief cloudy, the severe haze has a greater impact on the solar radiation rate, and the solar radiation rate in heavy haze day is 75 % less than that in non-haze day. (4) Precipitation influences solar radiation a lot, but precipitation level influences it little. Temperature has a little relation with solar radiation, however, the solar radiation rate reaches the maximum under the condition of temperature <0 ℃ or ≥30 ℃. Solar radiation decreases with the sunshine hours decreasing, but even when the sunshine hour is 0, the solar radiation rate also exists. The solar radiation basically increases with the visibility increasing. In the brief cloudy days, the maximal solar radiation is able to reach 1.53 times of the minimal one.