关键词: 能量通量, 地表反照率, 下垫面, 中国北方

Abstract: The characteristics of surface energy fluxes at Tazhong, Naiman, Pingliang and Jinzhou stations from August to October 2015 and Dingxi station from August to October 2016 were analyzed using observed data obtained from the Drought Meteorology Scientific Research: Mechanism and Disaster Formation Processes of Drought in the North Region of China. Surface radiations over different underlying surface showed significant diurnal variations. Compared to the downward short wave radiation and the downward long wave radiation, the difference between reflected radiation and the upward long wave radiation over different underlying surface was more significant. The reflected radiation and the upward long wave radiation at Tazhong station were the largest, and they were relatively small in Jinzhou station and Pingliang station. Net radiation had significant diurnal variation characteristics. The phase of net radiation and the total radiation was consistent, and the diurnal peak value of net radiation over farmland was larger. The average surface albedo of three months was the largest at Tazhong station (0.27), and then at Dingxi station (0.19), Jinzhou station (0.16), Naiman station (0.15) and Pingliang station (0.14). The sensible heat flux and latent heat flux at 5 stations were single-peak type. The peak value (276 W·m-2) of sensible heat at Naiman station was the largest, and the peak value of latent heat flux at Pingliang station was the largest. The energy dissipation at Dingxi station and Jinzhou station was mainly sensible heat flux, and it was mainly latent heat flux at Pingliang station.

Key words: surface energy fluxes, surface albedo, land cover types, Northern part of China