华北平原光合有效辐射的气候学计算方法

通过北京、烟台、郑州、济南等地生长李内对总日射(Q)和光合有效辐射(Q_(PAR))的连续自动记录,发现Q_(PAR)/Q值是比较稳定的,季节和云量对其影响不大。而太阳高度角较低时此值的变化,主要由仪器的余弦响应所引起。以目前总日射表的制造水准尚无法解决余弦响应的干扰问题。通过对实测资料的分析,得到了适合我国华北平原地区的计算公式为Q_(PAR)=0.42Q。过去国外的计算结果系统偏高,本结果与国内外最新研究成果相一致。

On the measurements and calculation of the photosynthetically active radiation (PAR)

From the long-term continuous automatic observation to the global solar radiation Q and PAR Q_PAR in Beijing, Yantai, Zhengzhou and Jinan during the growth period, it is discovered that the value of Q_PAR/Q is about stable. The effect of the season and cloud amount to it is nominal. The variation at the lower solar elevation is caused by the cosine response of the instrument. The current instrument manufacturing technique can not satisfy the need of the study on effect of the solar elevation on Q_PAR/Q. The analysis of the observation data gives that some formula parameters in abroad is higher,the computation formula Q_PAR = 0.42 Q which suitable to the east plain in China is obtained.