利用云量估算南京地区日总辐射方法的研究

Estimation of Daily Solar Radiation in Nanjing Using Total Cloud

为填补实测太阳辐射资料的空缺,利用南京地区1961年-2010年常规气象资料建立了由总云量反演逐日太阳辐射的模型,并对南京地区近50年来太阳总辐射的变化特征进行了分析。首先采用南京气象站1961年-2000年实测太阳总辐射数据借助粒子群优化算法确定了模型参数,然后利用2001年-2010年数据对模型效果进行了检验。结果表明:辐射模型模拟值与实测值拟合程度较好,Nash-Sutcliffe效率系数(NSE)、均方根误差(RMSE)和皮尔逊相关系数(r)分别为0.74、48.6W/m2和0.8。南京地区太阳总辐射受云量影响较大,其年内变化趋势基本与晴空辐射相吻合,但又存在差异,这主要是与梅雨季节有关。

Simple radiation estimation models using few input parameters are often used when rough estimations of solar horizontal radiation are required. Cloud cover information is widely available for multiple regional and national weather stations and cloud-based models for the estimation of global and diffuse horizontal irradiation are available. To further understand solar transfer at the water-air interface, variation in total solar radiation （E tot ） reaching the surface over Nanjing was examined here. A simple method to determine daily total solar radiation from commonly measured total clouds （TC） and theoretical short-wave solar irradiance under a clear sky condition （E clear ） has broad application. A 50-year （from 1961 to 2010） daily solar irradiance data set was collected to estimate peak solar irradiance for each ordinal data over one year, assumed to be representative of solar irradiance in the absence of clouds. Daily total clouds and solar radiation from 1961 to 2000 was used to establish a Nanjing solar radiation model. Particle Swarm Optimization was introduced for model calibration. A relationship between （E tot /E clear ） and TC produced a Nash-Sutcliffe Efficiency （NSE） value of 0.72, Root-Mean-Square Error （RMSE） value of 50.2 W/m 2 and Pearson correlation coefficient （r） value of 0.80. Results show that values of solar radiation derived from the model at Nanjing gave a reasonable prediction of the observed values, with a NSE value of 0.74, RMSE value of 46.5W/m 2 and r value of 0.8 for validation from 2001 to 2010. The Nanjing solar radiation model, E tot /E clear =1-0.743×（TC） 0.79 , was built to analyze variation in the daily total solar radiation at Nanjing.