Reconstruction Of Wind Stress State In Lop Nur Paleo Lake Based On Hydrodynamic Numerical Simulation

Lop Nur which is located in Ruoqiang County,Xinjiang Province,was once a vast ocean lake,and raised the ancient country of Loulan,which has a large population.But as the Tarim River was cut off,Lop Nur gradually dried up,and few people tread.Lop Nur region has only left a rare "big ear" and boundless salt crusts to highlight the glory of the past.Since ancient times,human beings have never stopped the scientific investigation and research in Lop Nur area.The unique "big ear" in Lop Nur is of great significance,and the formation of its special texture is considered to be the trace of lake retreat in the terrace of the lake shore.In previous studies,the accuracy of elevation data is limited.The "big ear" texture of Lop Nur has been considered as the contour line of lake water retreat.With the acquisition of high-precision DEM and more in-depth research,Wang Longfei obtained the phenomenon of "different heights in the same ring" by GLAS data analysis.The difference of height is about 1 m.The terrain here is not like the texture of the same elevation left by the lake surface,and the cause and mechanism of its formation need to be further studied.In this paper,the wind stress state during the formation of a ring pattern in Lop Nur's "big ear" is obtained by hydrodynamic numerical simulation,and the following conclusions are obtained.(1)Through the high precision DEM analysis of Lop Nur,it is concluded that Lop Nur has the phenomenon of "different heights in the same ring".From the outer ring to the inner ring,the height difference shows a phenomenon of decreasing and then increasing,which may be probably caused by geological action,artificial action and the wind which be considered as the most likely reason.(2)The main wind direction(68?)for E1 and E2 are about 11m/s which obtained by using hydrodynamic numerical simulation.The sub main wind direction are 12m/s and 11.5m/s for E1 and E2 respectively.The reason are similar which means this two line form in similar wind situation or in short-term.(3)The wind stress state in Tarim region changed little in Lop Nur dry period,but it still changed,the change of wind situation in NNW direction was more prominent than the dominant,and the climate between the two rings was mainly in the northwest wind.Due to the influence of Pacific circulation and Mongolian high the northwest wind in Lop Po area is different in the global climatic background during the formation of the two rings.