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The Study of Sandstorm Weather and Surface Heat Climate Characteristics in Taklimakan Desert

Author: WangMinZhong
Tutor: WeiWenShou
School: Xinjiang Normal University
Course: Physical Geography
Keywords: Taklimakan Desert sandstorm weather Ground Heat Fluxes climate characteristics Precipitation in South of XinJiang
CLC: P422
Type: Master's thesis
Year: 2008
Downloads: 84
Quote: 0
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Abstract

In this paper,using NCEP reanalysis data,micrometeorology data from the Taklimakan desert atmosphere environment observation experimentation station and conventional meteorology observational data,based on weather and climate analysis method,elementary researched east infused strong sandstorm weather of Taklimakan desert,ground surface radiation and heat balance in desert hinterland, climate characteristics of desert surface heat and the relations between surface heat and precipitation in south XinJiang. The results show that:1.The circulation dynamical structure of east infused strong sandstorm weather in April 10,2006.The eruptive and violence development of west Siberian cold high pressure principally caused strong sand-dust storms.Prophase dry and warm situation of Basin provide a well condition for sand-dust storms occurring.The vertical distribution feature of helicity over the sand-dust storms area is negative at the high level and positive at the lower,which implied that the strong rotating ascend is another one of the dynamical conditions of sand-dust storm;.The north filiation of direct circulation was advantageous to high jet momentum descend down,it promoted wind speed in mid and low level of troposphere,pushed down cold front southward,drove the occurrence and development of sand-dust storms.2.Taklimakan desert hinterland ground surface radiation and heat balance characteristic.Taklimakan desert ground surface radiation equilibrium is mainly positive,apart from the atmosphere downward longwave radiation,other components of the radiation (total radiation, reflection radiation,surface upward longwave radiation and net radiation) all have characteristics of day change,presents standard form of day cycle. The sensible heat flux makes up the major portion in the heat exchange of moving desert surface,none but little heat transport to surface atmosphere by latent heat.The surface sensible heat flux and latent heat flux rises and falls with varying sun height corner, latent heat peak value is at wee hours, sensible heat peak value is at midday.The analyses of surface heating field characteristics show that the land surface of Taklimakan Desert is a strong heat source in the daytime and it changes into a weak cold source in the evening.3.The climate characteristics of Taklimakan desert ground surface sensible heat and latent heat.The distributing of desert surface sensible heat and latent heat flux has great season and space differences.According to the EOF analysis of each season surface sensible heat and latent heat,there are three typical distribution patterns:“all-consisitent pattern”,“south-north reversal pattern”and“northwest- southeast reversal pattern”. In the last 25 years,variety trend of surface sensible heat flux of Taklimakan Desert is less evident as a whole on the first space scale in spring and summer,there has a obviously increscent trend in autumn.variety trend of surface latent heat flux of Taklimakan Desert have increscent trend on the first space scale in winter,spring,summer and autumn.4. Relations between taklimakan desert ground heat fluxes and summer precipitation abnormity in south of XinJiang.The first patterns from SVD indicate the coupling characteristic of ground heat fields and summer precipitation fields with closely temporal and spatial correlation.There is apparent negative correlation between ground sensiable heat fields of spring and summer in taklimakan desert and the summer precipitation in south of XinJiang,whereas ground latent heat field and the summer precipitation field present obviously positive correlation.The area of west and northwest in south of XinJing and desert middle part(37°N～40°N, 78°E～83°E)are prominence area of SVD coupling correlation.Ground sensiable heat and latent heat abnormity of taklimakan desert in spring is a forecast signal of summer precipitation abnormity in south of XinJiang.

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