Research On Surface Energy Budget In The North Margin Of Taklimakan Desert

Based on the latest January to December2011datas of radiation budget andsurface meteorological observation, and August to October2009datas of energybudget and surface meteorological observation in the north margin of TaklimakanDesert, It is analyzed the characteristics of radition budget and energy budget,stressed the otherness of budget in the different types of synoptic conditions,revealed the interaction between land and atmosphere in the desert and oasistransition zone.The major conclusions are given as follows:1.The annual and diurnal variation characteristics of radiation budget areanalyzed.The total yearly of global radiation, reflect radiation, atmospheric longwave radiation, surface long wave radiation and net radiation are separately5441.3,1446.3,7432.3,9596.8and1766.9MJ.m^-2.The maximum monthly total ofradiation budget components occur in June except net radiation and long waveradiation,others emerge in July. The total monthly of global radiation, reflectradiation, atmospheric long wave radiation, surface long wave radiation and netradiation are separately671.8,172.7,974.5,1243.3and224.6MJ.m^-2. And annualpeak instantaneous global radiation (1329.6W.m^-2) emerges on June18,12PM.2. Turbulent flux is calculated by eddy-covariance technique.The diurnalvariation of turbulent flux and soil heat fiux are analyzed. In energy budget balanceIn August, average daily total of sense heat,latent heat and soil heat flux,net radiationare separately4.2,0.7,0.1,5.9MJ.m^-2.d^-1.With52%,6%,16%（53%,3%,6%）of netradiation into sense heat, latent heat and soil heat flux separately thedaytime（nighttime） of In August.The rate of energy imbalance is26%（38%）.3.The energy budget under the typical weather, The peak of sense heat,latentheat and soil heat fiux,net radiation are separately244.2,44.9,122.6,414.2W.m^-2insunshine;Diurnal range of sense heat,latent heat and soil heat fiux,net radiationseparately reduce by7%,18%，38%，6%than the sunshine in cloudy; The daily totalof sense heat,latent heat and soil heat fiux,net radiation separately reduce by30%,45%，90%，38%than the sunshine in sand biowing;Diurnal range of senseheat,latent heat and soil heat fiux,net radiation separately are90%,81%，87%，83%ofthe sunshine in sand storm.4. The average value of the bulk transport coefficients, CD（CH）, respectively is 4.5×10^-3(2.2×10^-3) In August, and CD（CH）, respectively is4.2×10^-3(1.6×10^-3) InOctober. CDand CHhave remarkable diurnal and seasonal variation characteristic.Itis larger in summer than in winter.The value is large （small） at daytime （night）.5. The surface albedo is relatively larger （smaller） in winter （summer）. Theannual average surface albedo is0.27which is lower10%than Taklimakan deserthinterland （0.3）, but higher far oasis. The surface albedo which is （isn’t） covered withsnow varies between0.25and0.56（0.22and0.30）. The surface albedo becomessmaller with the increase of solar elevation angle.When the solar elevation angle isgreater than15°, the surface albedo changes very little and tends to be a constant.