A Study On Solar Radiation And Its Relation With Some Meteorological Elements In Chinese Mainland

The radiation budget of the Earth-atmosphere system plays a crucial effect to the heat and circulation station of the atmosphere and ocean,and forms the primary properties of the Earth climate.The radiation reached to Earth is one of physic factors affecting the climate and environment.So the research of ground solar radiation has significant sense to understand the effects of ground radiation's change to the change of environment and regional climate.Based on the data of 122 routine ground radiation observatories' Global radiation, Direct radiation,Scatter radiation and net radiation from 1961 to 2000,the quality control of the data used in the study were processed by the method of limitation test, to remove all the wrong data and missing data.We divide Chinese mainland into 5 different types of radiation region.In the study,the time and spatial distribution and the change properties of the solar radiation in China during this 40 years was analyzed Then in the combination of the data of each day's cloud cover and the visibility,a new model to calculate the solar Global radiation of any day in a year was put forwarded, and it's tested through the error analysis.In the end,the correlation between the temperature and the solar radiation received by the ground was presented in the combination of 729 stations' daily average temperature and 194 stations' daily maximum and minimum temperature,and tested by the significant test.The innovated research results are as follows:(1)Global radiation and Direct radiation declined during 1961-1990,but increased during 1990 to 2000,Increasing coefficient was significant in Tibetan plateau,but solar radiations did not get to the highest values in all areas.This phenomenon is anastomosis to "Dimming" and "Brightening" in all over the word. The decline rate of Global radiation is -1.24%/10a,-1.66%/10a,-1.60%/10a, -1.89%/10a and -1.93%/10a in every area.In recent 40 years,variation of Scatter radiation was not significant in northeast China,but declined in south Xin-Jiang and Qinghai-Tibet plateau and a little bit increase in South China.(2)By using statistical analysis on cloud cover,we found that low cloud cover increased in northwest China and both total cloud cover and low cloud cover decreased in other areas.The decline rate of total cloud cover is -2.99%/10a, -1.68%/10a,-3.10%/10a,-1.17%/10a and -1.01%/10a;the variation of low cloud cover is -1.51%/10a,4.46%/10a,-1.47%/10a,-0.89%/10a and -0.75%/10a in every area.The visibility in China was declined during 1961 to 2000,the downward trend was anastomosis to Global radiation.So we concluded that the reason of Global radiation decline before 1980 was caused by increased atmospheric particles.(3)The average temperature was increased during 1961 to 2000,increasing 0.84℃in recent 40 years,the DTR was a downward trend,decreased by 0.92℃. There was a significant correlation between average temperature,High temperature, Low temperature and Global radiation,Direct radiation,Scatter radiation and Net radiation,but also has inverse correlation between temperature and radiation.It shows that the increasing of atmospheric aerosol and greenhouse gases on the one hand it cause the decreasing of surface radiation,on the other hand it prevent long wave radiation.Lead to surface temperature increase.In spring surface receive radiation more than autumn,but temperature had not changed distinctly.The disproportion of radiation-temperature is corresponding with unique geography and climate in China.(4)The operative model based on cloud cover and visibility was built to estimate daily solar radiation easily.Compared the multivariate regression fitting value with the measured value,the results for 16 representative stations in the different region showed that:the fitted solar radiation value had significantly related to the observation value(R=0.76-0.92),RMSE was 3.6 MJ/m~2·d;MBE was 0.003 MJ/m~2·d; MABE was 2.72 MJ/m~2·d;MAPE was 19.10%.by using routine observation data of cloud cover and visibility,daily solar radiation can be easily estimated.