A well-calibrated simple and economical viable Ȧngström–Prescott model has long been accepted to be more accurate than other surface meteorological data-based models. The major limitation is that it is site dependent. This study exploited the appropriateness of a more generalized Ȧngström-based broadband hybrid model in the estimation of solar radiation at seven stations in equatorial region of West Africa. This model features parametric equations that explicitly and accurately account for clear-sky damping processes in the atmosphere. It empirically estimates cloudy sky radiation extinctions using relative sunshine duration. A new cloud transmittance calibration curve that followed the cloud cover patterns of the region of study was also tried. The result indicated that the new cloud transmittance could be unique to equatorial region of West Africa. The performance of the hybrid model, after modification using the new cloud transmittance equation, was tested using mean bias error and root mean squared error. The performance was found to be comparable to the site-dependent, locally calibrated, Ȧngström–Prescott model at the calibration stations, and even better at validation stations. The same performance test comparisons with the original version of the hybrid model, and four other site-independent models: globally calibrated, FAO-recommended Ȧngström–Prescott models, Hay and Gopinathan models indicated the modified version of the hybrid model as better

中文翻译：

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使用更广义的基于 Ȧngström 的宽带混合模型估算西非赤道地区的每日太阳辐射

长期以来，一个经过良好校准的简单且经济可行的 Ȧngström-Prescott 模型被认为比其他基于地表气象数据的模型更准确。主要限制是它依赖于站点。本研究利用了更广义的基于 Ȧngström 的宽带混合模型在西非赤道地区七个站的太阳辐射估计中的适用性。该模型具有参数方程，可以明确而准确地解释大气中晴空阻尼过程。它使用相对日照时间凭经验估计多云天空辐射消光。还尝试了遵循研究区域云量模式的新云透射率校准曲线。结果表明，新的云透射率可能是西非赤道地区独有的。在使用新的云透射率方程修改后，混合模型的性能使用平均偏差误差和均方根误差进行测试。发现其性能与校准站的现场相关、本地校准的 Ȧngström-Prescott 模型相当，在验证站甚至更好。与原始版本的混合模型和其他四个独立于站点的模型的相同性能测试比较：全球校准、FAO 推荐的 Ȧngström–Prescott 模型、Hay 和 Gopinathan 模型表明混合模型的修改版本更好 使用平均偏差误差和均方根误差进行测试。发现其性能与校准站的现场相关、本地校准的 Ȧngström-Prescott 模型相当，在验证站甚至更好。与原始版本的混合模型和其他四个独立于站点的模型的相同性能测试比较：全球校准、FAO 推荐的 Ȧngström–Prescott 模型、Hay 和 Gopinathan 模型表明混合模型的修改版本更好 使用平均偏差误差和均方根误差进行测试。发现其性能与校准站的现场相关、本地校准的 Ȧngström-Prescott 模型相当，在验证站甚至更好。与原始版本的混合模型和其他四个独立于站点的模型的相同性能测试比较：全球校准、FAO 推荐的 Ȧngström–Prescott 模型、Hay 和 Gopinathan 模型表明混合模型的修改版本更好