Surface heat flux analysis in gobi desert steppe, Mongolia - an observation study

Abstract

41% of Earth's land area is drylands, including the arid region of China and Mongolia. Evaporation per unit area of arid region is relatively low, but the surface area of the dryland region gives it a regional significance in the context of climate variability. We used the eddy covariance method to estimate heat fluxes in the Gobi Desert steppe of Mongolia from May to October 2014. Observation period averaged net radiation, sensible heat flux, and latent heat flux were 85 W m-2, 58 W m-2, and 11 W m-2, respectively. The sensible heat flux was larger than the latent heat flux throughout most of the study period, but the latent heat flux exceeded the sensible heat flux for a couple of days after rainfall events. Total evaporation estimated by the eddy covariance method almost equaled total rainfall and decreased the soil water content. Discussion is extended to the imbalance problem, especially the latentheat heat flux compared with precipitation and the soil moisture change.