CO₂Flux Characteristics Of Taklimakan Desert Hinterland

The rise in atmospheric CO2concentration will exert a great effect on the global climate.Not surprisingly, the carbon cycle problem has always been a research focus all over the world.Nonetheless,there is an important subject area in this field, called missing carbon sink.,that has remained relatively unexplored until now.Though some studies on the topic of missing sink have been carried out,the results obtained are somewhat sketchy and inconclusive.In2004Li Yan reported that the soil of Gurbantunggut Desert absorbed CO2at night in a formal experiment.The discovery created a new direction for finding missing sink.In recent years.a number of studies studis on the carbon cycle of the desert have been carried outThe results show that some deserts act as a sink of CO2, while some others play the role of a source.Because the Taklimakan is the second largest desert on earth,it is very important to determine whether the Taklimakan is a sink or a source.In this work,we first analysize the influence of atmospheric CO2concentration on air temperature using the temperature date of three cities located in the vicinity of the Taklimakan and the atmospheric CO2concentration dates of Mt.waliguan for the past20years.It turns out that air temperature rises with increasing atmospheric CO2concentration.Tthe influence of atmospheric CO2concentration is found to be larger in cases with low values of air temperature.Secondly, the CO2flux characteristics of Tazhong and Xiaotang area in different seasons are studied.The results show that Tazhong area is a sink of CO2.The strength of CO2absorption by soil in spring is stronger than that in winter.it is also stronger on fine days than on cloudy days.Tazhong area exhibits a stroner strength of CO2absorption by soil.than Xiaotang area.Besides, the CO2flux is significantly affected by floating sand,scattering dust and sand storm weather,whit the wind speed being the most influential factor.Finally,the influence of meteorological elements in surface layer on CO2flux is studied. It is concluded that there are negative correlations of different degrees between CO2flux and topsoil temperature, topsoil moisture,air temperature,net radiation, sensible and latent heat flux. In addition, it is found that unstable atmospheric conditions and rainfall are conducive to the absorption of CO2.