荒漠绿洲过渡带飘尘垂直分布特征及其主要气象影响因素

Vertical Distribution Characteristics and the Main Meteorological Factors of Floating Dust in a Desert-oasis Ecotone of Ebinur Basin,Xinjiang Uygur Autonomous Region

利用激光尘埃粒子计数器,结合气象梯度自动观测系统,于2014年7月植物生长季获取新疆艾比湖湿地国家级自然保护区东大桥管护站附近7个高度(2,3,6,12,15,21,27m)上6个粒径段(0.3μm≤x<0.5μm,0.5μm≤x<1.0μm,1.0μm≤x<3.0μm,3.0μm≤x<5.0μm,5.0μm≤x<10.0μm,10.0μm≤x)飘尘浓度和气象数据,探究了该区域内空气飘尘垂直分布特征与主要气象影响因素。结果表明:研究区飘尘各粒径组分中,0.3μm≤x<3.0μm所占比例最高,累计贡献率高达97.6%。飘尘总浓度(0.3μm≤x)在7个高度上的分异规律为C3m>C6m>C2m>C21m>C27m>C12m>C15m,表现出中间低两头高的"哑铃效应"。气象—飘尘回归方程反演的飘尘数据与实测数据呈现显著正相关(p<0.05),且与实测日变化趋势基本一致。风速对飘尘浓度有极显著(p<0.01)的双重作用,风速小于临界值有利于飘尘积累,反之促进飘尘稀释,且正反效应的临界值随高度的增加而降低;相对湿度的增加极显著(p<0.01)地降低飘尘浓度。

Six particle size interval （0.3μm≤x〈0. 5μm, 0. 5 μm≤x〈1.0 μm, 1.0 μm≤x〈3.0 m, 3.0μm≤x〈5.0μm, 5.0 μm≤x〈10.0 μm, 10.0μm≤x） floating dust concentrations and meteorological data on seven kinds of height （2, 3, 6, 12, 15, 21, 27 m） were measured by the laser dust particle counter and automatic observing system for meteorological gradient to study vertical distribution characteristics and the main meteorological factors of floating dust in a Desert oasis Ecotone of Ebinur Basin, Xinjiang Uygur Autonomous Region. The results showed that the average contribution of 0.3 μm≤x〈3.0μm among different size interval floating dusts accounted for the highest, add up to 97.6 . The distribution rule of floating dust overall contribution （0.3 μm≤x） on the seven layer heights was high on both sides of the middle low （C3m〉 C6m〉C2m〉C21m〉C21m〉C27m〉C12m〉C15m）, which could be called ＇dumbbell effect＇ Analogue data obtained from meteorological-floating dust regression equation and measured data showed the significantly positive correlation （p〈0.05）, and the diurnal variation trend of analogue data was similar to the measured data. Wind speed had the significant positive and negative effects on floating dust concentrations （wind speed less than the critical value in favor of floating dust accumulation, whereas promoted floating dust diluted） （p〈0. 01）, and floating dust concentration reduced obviously （p〈0. 01） with the increase of relative humidity.