双通道辐射量计算太阳极紫外辐射E_(10.7)指数方法初探

Use Double Channel Solar Irradiance Flux to Compute the E_(10.7) Index

从太阳极紫外辐射研究的重要性出发,介绍了太阳极紫外辐射E_(10.7)指数及其作用,详细阐述了利用两个能道的太阳辐射观测值计算极紫外辐射E_(10.7)指数的计算方法.利用该方法对实测太阳辐射数据进行处理,计算获得了2000—2005年的每日E_(10.7)指数,并将计算结果与Solar 2000模式的输出结果进行对比分析,验证了该计算方法的可行性,对比结果表明,最大相对误差在20%以内,平均相对误差均在10%以内.

Solar Extreme Ultraviolet （EUV） plays an important role in space weather research and forecasting. The E10.7 index is the integrated EUV energy flux at the top of the atmosphere. Solarv2000 model combines the best of empirical and physics-based models to provide a wide variety of solar irradiance products for science and engineering applications, including E10.7 integrated EUV flux etc. In this paper, the physics significance of the E10.7 index is described, and a new computation method of E10.7 index is also described in details. Double channel solar irradiance flux were used to compute the E10.7 index. At first the experiential coefficients were obtained based on the empirical expression and historical solar irradiance data picked up from the Solar 2000 model. Then the new method was applied to solar irradiance flux data from the year of 2000 to 2005, and successfully yields the Ei0.7 index. The differences between the compute result and the result from Solar2000 model were calculated. The comparison results show that the mean relative deviation is within 10% with a maximum deviation less than 20%.