Abstract:
Meteorological variables observed at China Meteorological Administration(CMA) stations may differ from those in field stations due to the effects of urbanization and other factors related to CMA observations.This hampers the application of the determined thermodynamical parameters from field experiments in estimating the sensible heat flux over the arid region of Northwest China.This study chooses several broadly used surface flux parameterization schemes(including Z10, B82, Z98, Y08, Z12, etc.) and tests their sensitivities to momentum roughness length.It also tests their application in the arid region of Northwest China by comparing the sensible heat flux estimation at Dunhuang with observations and estimations of summer sensible heat flux over the whole arid region of Northwest China from CMA data. The results indicate that the scheme taking the bulk transfer coefficient for heat as a constant may bring much uncertainty to sensible heat flux estimation over the arid region.It is advised that the momentum roughness length at CMA stations should consider that of the natural underlying surface where the station is located when determining the sensible heat flux, although it may be disturbed by urbanization and other factors.The sensible heat flux estimated by the Y08 scheme seems relatively reasonable, and therefore the use of this scheme is advised when analyzing the characteristics of summer surface sensible heat flux over the arid region of Northwest China.