1961—2000年中国太阳辐射区域特征的初步研究

 利用中国122个辐射观测站1961—2000年的逐日地面辐射资料,同期729个气象站的逐日云量资料,分析了总辐射、直接辐射和散射辐射年代际距平分布和变化。按照中国地理气候区域的特征并考虑年总辐射,将中国划分为5个不同的辐射区域。分析了各区近40 a来总辐射、直接辐射、散射辐射的年际变化。结果表明:①总辐射和直接辐射年曝辐量在1961—1990年之间呈下降趋势,在20世纪80年代达到最低值,以青藏高原西南部地区降幅最明显;在1991—2000年总辐射和直接辐射年曝辐量有回升趋势,其中青藏高原地区回升最显著,但均未达到历史最高水平。5区总辐射近40 a来下降率为:-1.24%/10a,-1.66%/10a,-1.60%/10a,-1.89%/10a和-1.93%/10a。②近40 a来散射辐射年曝辐量除东北无明显变化外,南疆和青藏高原有降低趋势,而南方有略微增加趋势;通过对云量的分析发现西北地区低云量略增加,而其他地区低云量和总云量都有不同程度的下降趋势,5区总云量近40 a来下降率为:-2.99%/10a,-1.68%/10a,-3.10%/10a,-1.17%/10a和-1.01%/10a,低云量变化率为:-1.51%/10a,4.46%/10a,-1.47%/10a,-0.89%/10a和-0.75%/10a。最后对造成辐射长期变化的原因作了初步讨论。

Primary Study on Regional Characteristics of Solar Radiation in China during 1961-2000

By using the data of global radiation, direct radiation and scatter radiation from 112 stations, and cloud cover from 729 stations in China during 1961 to 2000, the inter-decadal anomaly spatial distribution and change were analyzed. Based on the value of global radiation, we divided whole China into 5 radiation areas, and then analyzed their variation characteristics of solar radiation. Results show that: ①Global radiation and direct radiation declined from 1961 to 1990, reaching the lowest at 1980’s and being obviously at the southwest of Qinghai-Xizang Plateau; increased from 1990 to 2000, being significant in Qinghai-Xizang Plateau, but the solar radiation did not reach the highest value in history. The decreasing rate of global radiation in the above five regions was respectively -1.24%, -1.66%, -1.60%, -1.89% and -1.93% per ten years during the 40 years. ②In the 40 years, the variation of scatter radiation was not significant in northeast China, but declined in south Xinjiang and Qinghai-Xizang Plateau and a little increase in south China. ③The low cloud cover increased in northwest China, and both total cloud cover and low cloud cover decreased in the other areas. The declining rate of total cloud cover in the above five regions was respectively -2.99%, -1.68%, -3.10%, -1.17% and -1.01% per ten years; those of low cloud cover was respectively -1.51%, 4.46%, -1.47%, -0.89% and -0.75% per ten years. At last, the reasons for long-term variation of radiation were discussed.