PSP总日射表热偏移特征及其测量总辐射误差分析  

CHARACTERISTICS OF THERMAL OFFSET OF A PRECISION SPECTRAL PYRANOMETER(PSP) AND ITS ERROR IN GLOBAL SOLAR RADIATION MEASUREMENT

作　　者：程兴宏[1,2] 张小玲[3] 郑向东[1] 周怀刚[4] 李德平[5] 

机构地区：[1]中国气象科学研究院,北京100081 [2]国家气候中心,北京100081 [3]中国气象局北京城市气象研究所,北京100089 [4]中国气象局上甸子区域大气本底站,北京101507 [5]北京市观象台,北京100089

出　　处：《太阳能学报》2009年第1期19-26,共8页Acta Energiae Solaris Sinica

基　　金：中国气象局城市气象研究所2005年度开放项目(UMRF200508)

摘　　要：根据2004年7月～2006年5月期间北京上甸子大气区域本底站Eppley PSP总日射表观测太阳辐射数据,分析了PSP表的热偏移特征及其影响因子,并以Eppley8-48型日射表和NIP直射表分别观测的散射和直射辐射之和作为总辐射的标准值,分析了PSP总辐射的误差特点及其影响因素。研究表明:PSP总日射表的热偏移呈现正态分布特征,平均值为-8.8±2.7W·m^(-2);PSP表热偏移显著受到净长波辐射、风速、相对湿度和温度的影响,其中与风速和相对湿度的相关性最为明显。与标准的太阳总辐射观测值(水平面上的散射与直射辐射之和)相比,未做热偏移订正的PSP总辐射的平均误差约为-20.0W·m^(-2),经过当日平均热偏移订正后,平均误差接近-11.0W·m^(-2)。PSP表测量的总辐射绝对误差也呈准正态分布特征,但晴天与云天略有区别。PSP总辐射的相对误差与太阳天顶角的变化以及云量均有相关关系,反映了半球型辐射表的余弦效应对PSP总日射表测量精度的影响。太阳辐射的强弱变化或总辐射中散射与直射所占比率的相对变化也对PSP总日射表的测量精度有一定影响。研究表明:总日射表测量的总辐射应考虑热偏移订正,总日射表标定还应考虑云的影响。Thermal offset of Eppley Precision Spectral Pyranometer （PSP） and its associated factors were presented on the basis of solar radiation observation made at Shang Dianzi, a regional GAW site near Beijing, during July, 2004 - May, 2006. PSP error in global radiation measurements and the associated factors were also analyzed, regarding as the ＇standard＇ global radiation which is sum of scattered and directed radiations respectively collected by Epply 848 pyranometer and Normal Incidence Pyrheliometer （NIP）. The results showed that probability distributions of PSP thermal offset tends normal distribution mode and the average thermal offset is - 8.8 ± 2.7W· m^- 2. The net infrared long-wave radiation, wind speed, relative humidity and temperature near the surface level have significant influenees on the PSP thermal off- set, especially wind speed and relative humidity. Compared with the ＇ standard＇ of global radiation, the average PSP error in global radiation measurement is around - 20.0 W· m^- 2 / - 11.0W· m^- 2 without/with the compensation of thermal offset. The probability distribution of PSP error in global radiation measurement also tends normal distribution with the distinguishable difference in clear and cloudy days. Obvious correlations between relative PSP error in global radiation measurement and solar zenith angle as well as cloud amounts, reflect that of the cosine effect of pyranometer. Aeeuraey of PSP global radiation data were also influenced by ratio of directed in global radiation which may be caused by eloud amounts. It is suggested that global radiation data collected by pyranometer should be eorreeted by thermal offset and the calibration for pyranometers in cloudy days.

关 键 词：PSP总日射表 热偏移特征 PSP测量误差 

分 类 号：P422.1[天文地球—大气科学及气象学] TH765.21[机械工程—仪器科学与技术]