光合有效辐射是太阳辐射的一部分,是植被进行光合作用和陆地生态系统碳循环的核心因素,对估算植被生产力具有重要影响。本文基于SURFRAD多年观测数据,建立了一个线性回归模型,由上午、下午瞬时光合有效辐射值估算日均值。该模型模拟效果较好,单个观测站的均方误差低于9 W·m-2,判定系数不低于0.96,并适用于不同经纬度、气候条件和海拔高度下的区域,总的均方误差为8.863 1 W·m-2, 判定系数R2为0.977,表明该模型和方法有较好的可行性和可靠性。
Photosynthetically active radiation (PAR) commonly refers to solar radiation in the visible (400-700 nm) part of the electromagnetic spectrum.Despite its potential and critical application in terrestrial ecosystem modelling,surface PAR is not typically a routine observation at meteorological station.Remote sensing can be used to derive the spatiotemporally continuous instantaneous PAR,but the researches about daily PAR estimation are deficient,and their accuracy cannot be guaranteed.In this paper,a linear regression model was developed to calculate the daily PAR based on Surface Radiation Budget Network (SURFRAD) data through the instantaneous and theoretical PAR.The results indicated that the model was effective with root mean square errors (RMSE) about 8.863 1 W·m-2,with coefficient of determination (R2) about 0.977 without the limitations of areas.
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