The HelioMont method for assessing solar irradiance over complex terrain: Validation and improvements

REMOTE SENSING OF ENVIRONMENT

卷:152

Article

Castelli, M.¹  Stoeckli, R.²  Zardi, D.¹  Tetzlaff, A.³  Wagner, J. E.³  Belluardo, G.⁴  Zebisch, M.³  Petitta, M.⁵ 

[1] Univ Trento, Dept Civil Environm & Mech Engn, Atmospher Phys Grp, I-38123 Trento, Italy

[2] Fed Off Meteorol & Climatol MeteoSwiss, CH-8044 Zurich, Switzerland

[3] European Acad Bolzano, Inst Appl Remote Sensing, I-39100 Bolzano, Italy

[4] European Acad Bolzano, Inst Renewable Energy, I-39100 Bolzano, Italy

[5] UPRSE, ENEA Casaccia, I-00123 Rome, Italy

关键词: Solar surface irradiance;    Diffuse radiation;    Aerosols;    Radiative transfer modeling;    Remote sensing;   

DOI  :  10.1016/j.rse.2014.07.018

来源: Elsevier

【 摘 要 】

This study evaluates the suitability of the method HelioMont, developed by MeteoSwiss, for estimating solar radiation from geostationary satellite data over the Alpine region. The algorithm accounts for the influence of topography, clouds, snow cover and the atmosphere on incoming solar radiation. The main error sources are investigated for both direct and diffuse solar radiation components by comparison with ground-based measurement taken at three sites, namely Bolzano (IT), Davos (CH) and Payeme (CH), encompassing different topographic conditions. The comparison shows that the method provides high accuracy of the yearly cycle: the Mean Absolute Bias (MAB) is below 5 W m(-2) at the lowland station Payerne and below 12 W m(-2) at the other two mountainous stations for the monthly averages of global and diffuse radiation. For diffuse radiation the MAB is in the range 11-15 W m(-2) for daily means and 34-40 W m(-2) for hourly means. It is found that the largest errors in diffuse and direct radiation components on shorter time scales occur during summer and for cloud-free days. In both Bolzano and Davos the errors for daily-mean diffuse radiation can exceed 50 W m(-2) under such conditions. As HelioMont uses monthly climatological values of atmospheric aerosol characteristics, the effects of this approximation are investigated by simulating clear-sky solar radiation with the radiative transfer model (RTM) libRadtran using instantaneous aerosol measurements. Both ground-based and satellite-based data on aerosol optical properties and water vapor column amount are evaluated. When using daily atmospheric input the estimation of the hourly averages improves significantly and the mean error is reduced to 10-20 W m(-2). These results suggest the need for a more detailed characterization of the local-scale clear-sky atmospheric conditions for modeling solar radiation on daily and hourly time scales. (C) 2014 The Authors. Published by Elsevier Inc.

【 授权许可】

Free