Angstrm公式参数率定及其随经度与海拔的变化

Calibration of Angstrm Coefficients and Its Variation with Longitude and Altitude

在相近纬度条件下,选择不同经度和海拔区域的数据率定计算太阳辐射的2个重要参数as、bs,并分析as、bs与相关影响因素之间的关系。结果表明,沿海地区as、bs分布较集中,且均略小于内陆地区。采用as、bs率定值计算Rs,计算精度(RMSR小于3.7MJ/(m2·d))比采用FAO56推荐值高。有实测资料的地区,应采用地区率定的as、bs值进行辐射计算;此外,以经度、海拔和相对日照时数作为影响因素建立相近纬度范围内站点as、bs率定值的计算方法,可用于相近纬度范围内无资料地区辐射的估算。

Under similar latitude conditions, as and bs were local calibrated and evaluated based on data from stations with different longitudes and altitudes. Then relationships between as, bs and related influ- ence factors were analyzed. Results showed that the values of as and bs in coastal areas were concentrative distributions and were slightly less than those in inland areas. The calculated accuracy with RMSE below 3.7 MJ/（m2 · d） using local calibrated coefficients was higher compared to that using FAO56 recommen- ded parameters. Thus, in the areas with measured data, local calibrated as and bs were strongly recommen- ded to calculate radiation. Besides, the estimated methods of as and bs were proposed on the basis of longti- tude, altitude and relative sunshine hours in similar latitude areas, which could be used to estimate radia- tion in those areas without measured data.