黑河上游阿柔草场冻融过程及其对地表辐射平衡的影响  

Freezing and thawing processes and their impact on ground surface radiation balance in the upper reaches of Heihe River

作　　者：王庆峰[1] 张廷军[2,3] 彭小清[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,兰州730000 [2]兰州大学干旱环境与气候变化协同创新中心,兰州730000 [3]兰州大学资源环境学院,兰州730000

出　　处：《兰州大学学报（自然科学版）》2013年第2期182-191,共10页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(91025013);冻土工程国家重点实验室国际合作项目(SKLFSE-ZY-06)

摘　　要：在黑河上游青海省祁连县阿柔乡取得陆而过程观测资料,分析了冻融过程中土壤水热变化及其对地表反照率、辐射平衡各分量和净辐射的影响.结果表明:下层土壤的始冻期和解冻期均滞后于上层土壤的.冻结速率与气温表现为明显的反相位变化,而自上融化的速率则与气温表现出相同的变化趋势.土壤水分在始冻期和解冻期前后变化很大,而在完全冻结期变化较小.在始冻期前后土壤水分的变化主世是由土壤水的相变和土层间的水分迁移造成的,而解冻期前后的则是土壤水的桕变、降水过程和地表蒸散共同作用的结果.完全冻结期的地表反照率大于始冻期和解冻期的.冻融过程中的总辐射和反射辐射的变化可以分为三个阶段:减小—增加—略微减小.地表向上长波辐射和大气逆辐射的变化则可分成减小-增加-略微增加三个阶段.受太阳短波辐射的控制,净辐射依次表现为减小—增大—增大的变化趋势.The land surface process observation data used here came from Arou Town, Qilian County in Qinghai Province in the upper reaches of Heihe River, analyzed the soil moisture and thermal changes and its impact on the ground surface albedo and each component of the ground surface radiation balance in the freezing and thawing processes. The results showed that the beginning and ending date of freezing were both lagging behind the upper layer. The freezing rate obviously followed air temperature undulation inversely, while the thawing rate downwards showed the same trend with air temperature. Soil moisture changed much before and after the beginning dates of freezing and thawing, while it changed little in the freezing period. Changes in soil moisture were mainly caused by the soil water phase change and migration between different layers before and after the beginning date of freezing, while they were the effect of the soil water phase change, precipitation processes and the ground surface evapotranspiration before and after the beginning date of thawing. Ground surface albedo in the freezing period was bigger than that in the beginning and ending dates of freezing. Changes of the total radiation and the reflected radiation in the freezing and thawing period were both divided into three stages, i.e. a decrease stage to an increase stage and then to a slight decrease stage. While changes in upward long wave radiation and downward long wave radiation were both divided into a decrease stage to an increase stage and then to a slight increase stage. Controlled by the solar shortwave radiation, the net radiation showed a decreasing trend to an increasing trend and then to an increasing trend in turn.

关 键 词：冻融过程 土壤水热特征 辐射平衡 黑河上游 

分 类 号：P422[天文地球—大气科学及气象学]