格尔木地区总辐射、反射辐射的变化特征

格尔木辐射站是青海省唯一的太阳辐射观测一级站,地处柴达木盆地,太阳总辐射及地表反射辐射均较强.1993—2011年19 a的观测结果表明：反射辐射时总量的变化规律与总辐射时总量同步,只是量值比较小,总辐射瞬时最大值为1 596 W/m2,反射辐射瞬时最大值为383 W/m2;总辐射日总量、反射辐射日总量的年变化曲线呈不规则的正弦波曲线变化过程,两者变化趋势完全一致;总辐射日总量、反射辐射日总量的年变化、年际变化与日照时数相同,说明日照时数是太阳总辐射、反射辐射的重要影响因素之一;总辐射日总量、反射辐射日总量均是夏季〉秋季〉春季〉冬季,反射比是冬季〉春季〉秋季〉夏季;反射比分布主要与太阳高度角的变化有关,反射比的大小取决于地面的性质和状态,地面被积雪覆盖时,各时及日反射比值明显大于晴天和土壤潮湿的时期.

Changing characteristics of total radiation, reflected radiation in Golmud region of Qinghai province

As the only solar radiation observation station in Qinghai province, the Golmud station is located in Qai- dam Basin with strong total solar radiation （SD） and surface reflected radiation （SRD）. The temporal variation char- acteristics of solar radiation in Golmud region are analyzed using observation data during 1993--2011. The results show that the hourly total SRD and SD changes in the similar pattern, though the SRD is small in value compared with SD ,with instantaneous maximum SRD being 383 W/m2 while instantaneous maximum SD being 1 596 W/ms. The annual dynamics of daily total SD and SRD followed the same trend, which is an irregular sine wave curve. The annual and inter-annual variation of daily total SD and SRD showed the same pattern with that of sunshine duration, indicating that the sunshine duration is a significant influencing factor of SD and SRD. The seasonal variation of dai- ly total SD and SRD showed the same trend, which are most in summer, followed by in fall, then in spring, and least in winter. While the SRD ratio is most in winter, followed by in spring, then in fall, and least in summer. The distri- bution of RSD ratio is related with changing of the solar altitude angle. The RSD ratio is mostly dependent on the surface properties, when the ground is covered with snow in winter, both the hourly and daily RSD ratio are appar- ently greater than that in sunny days or periods with moist soil.