Spatio-temporal Distribution Of Near-surface Temperature In Mountains Over The Northwesternmost Tibetan Plateau

The climate in Asia even the whole world is further complicated by mass elevate on and extensive mountain regions on the Tibetan Plateau on which the northwestmost is suitable for studying Global Warming with The Natural Environment responding ob viously for Global Warming and having been disturbed less by the human activity.Not only does the near surface temperature affect directly ecosystem but also influence ind irectly the Producing and Living,but unfortunately,the meteorological measurementdata has been extremely insufficient over the northwesternmost Tibetan Plateau and the rese arch with temperature has been on implement rarely.The lapse rate of near surfaceair t emperature is an important parameter for estimating the spatio-temporal distributionof t emperature at mountain regions with less meteorologically measuring and Surfaceenviro nmental process simulation,so It's necessary of implement for the study of near-surface temperature?NST?and near surface temperature lapse rates?LR?over the Northwesternm ost Tibetan Plateau.Basedon the meteorological measurement data of National standard meteorological stations and self-established weather stationsin the Tizinafu River Basin on the northern slopes of kunlun Mountains,this study analyse the spatio-temporal distr ibution of NST applying sin function and Spatial interpolation?inverse distance weighti ng,IDW?,calculate the numerical value of LR employing Unary linear regression and Multiple Regression Analysis,analyse the spatial and temporal distribution,estimate quan titatively the degree of influence for Meteorological elements on LR making use of C orrelation analysis statistics and Grey Relational Analysis,lastly analyse theperiodic vari ation?variation trend and annual abrupt time of NST and LR employingthe nonparame tric methodssuch as the Morlet wavelet analysis and Mann–Kendall test.The results sh owed:?1?the spatial and temporal distribution for NST are revealed over the Northwest ernmost Tibetan Plateau.At the National standard meteorological stations region,the NST of Mid-Mountain Area compared to the NST of The Hill Area,The amplitude of which volatility is sma ller,the period of which volatility is shorter,the fluctuating time point of which is later.The appearance time point of max daily mean temperature is later in comparison with max monthly mean temperature in the Hill Area and Mid-Mountain Area.After 1986,th e NST of daily/monthly mean temperature,The amplitude of which volatility is smaller,the period of which volatility is shorter,the fluctuating time point of which is later in the Hill Area,contrary to Mid-Mountain Area.At the self-established weather stations region,with higher altitude of the observati on area,with smaller amplitude of NST volatility,later fluctuating time point.The period s of NST volatility are approximately equal in different altitudinal areas.The phenome non of the difference value in the High-Mountain Area and the Mid-Mountain Area of NST volatility amplitude far exceeding the difference value in the Mid-Mountain Area and Hill Area shows Temperature Inversion present between the High-Mountain Area and the Mid-Mountain Area.The phenomenon of time points being not synchronized fo r min dailymean temperature and min monthly mean temperature appear in various alti tudinal areas and more frequent for the higher elevation.The result of Correlation anal ysis statistics shows that:the spatial difference of NST is more drived by altitudinal dif ference less by different longtitude for various stations.?2?the spatial and temporal distribution for LR are revealed over the Northwester nmost Tibetan Plateau.Overall,for the annual mean LR,LR_Tave?LR_Tmin?LR_Tmaxmax at the self-established weat her stations region are found lower than the LR_Tave?LR_Tmin.The value of LR is max in summer min in winter.The difference value among the three types of LR is max in w inter.The difference of LR_Tmaxmax is most notable in various season.The LR value is stable in various months.At the National standard meteorological stations region,Among the t hree types of LR,the spatial difference of LR_Tmaxmax is least significant while the spatial d ifference of LR_Tminmin is most significant.At National standard meteorological stations regio n,for the seasonal mean LR,the value of LR is max in spring min in winter.The differ ence value among the three types of LR is max in winter.The difference of LR_Tmaxmax is most notable in various seasons.After 1986,the value of LR_Tave?LR_Tminmin has increased,the value of LR_Tmaxmax is stable.T he seasonal variability of three types of LR over the northwesternmost Tibetan Plateau is different from Xinjiang region even national scale.Except for LR_Tminmin at the National standard meteorological stations region,LRs in the study area are smaller than 0.65?/100 m.The influence for Meteorological elements on LR shows that:At the National stan dard meteorological stations region,Relative humidity is chief effective,Wind Speed is s econdary effective,Precipitation is lastly effective.At the self-established weather stations region,Temperature is chief effective,Wind Speed is secondary effective,Relative humid ity is lastly effective.?3?The variation trend and variation period are revealed for NST and LR at Nati onal standard meteorological stations region.The increased trend of NST is founded at Hill Region.The increasing speed are r espectively:0.0344?/a in autumn,0.0315?/a in winter,0.0281?/a at annual scale,0.0253?/a in spring,0.0214?/a in summer.The annual abrupt time points are respectively:1999a at annual scale,2000a in spring,1985a in summer,1995a in autumn,1996a in winter.The increased trend of NST is founded at annual?spring?summer?autumn scales at Mid-Mountain region.The increasing speed are respectively:0.0347?/a in spring,0.0324?/a in autumn,0.0250?/a at annual scale,0.0184?/a in summer.The annual abrupt time p oints are respectively:1988a at annual scale,1994a in spring,1991a in summer,1989a in autumn.For annual average temperature,there is more distinct increasing trend of NST and later annual abrupt time at Hill Region relative to Mid-Mountain Region.In spring,there is more distinct increasing trend and earlier annual abrupt time at Mid-Mountain Region relative to Hill Region.In summer,there is more distinct increasing trend and earlier annual abrupt time at Hill Region relative to Mid-Mountain Region.The pheno menon of Autumn is same to annual scale.Overall,there is more distinct increaseng tr end and later annual abrupt time at Hill Region.The least increased trend of LR is fo unded at annual?summer?autumn?winter scales,but all of which are not subject to si gnificance test?besides for spring?.The annual abrupt time points of LR arerespectively:2002a at annual scale,1967a in spring,2003-2006a in summer,1980a in winter.At annual and seasonal scales,there is annual full-time period of 25³7a at Hill Region and Mid-Mountain Region and there presents main period of 30 years or so?m ostly 30years?except for the main period of 15years in winter.At annual and spring?autumn scales,there is just yearly scale period at Mid-Mountain Region compared to H ill Region.Both at Hill Region and Mid-Mountain Region,there presents decadal scale period in summer,there presents multi-time scale including yearly and decadal periods.For LR there are annual full-time main period of 25³5a at annual scale,25³7a at spring scale,25³5a at summer scale,23³5a at autumn scale.There presents main period of 32a at both annual and seasonal scales except at winter scale where present s hardly full-time period and highest peak value in Wavelet variance analysis correspo nding to a scale of 25a or so.