Micrometeorological Conditions for Dust-Devil Occurrence in the Atacama Desert
Micrometeorological Conditions for Dust-Devil Occurrence in the Atacama Desert
复制标题
阿塔卡马沙漠沙尘暴发生的微气象条件
DOI：
10.1007/s10546-010-9549-1
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发表时间：
2011
影响因子：
4.3
通讯作者：
S. Metzger
中科院分区：
文献类型：
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作者：
M. Kurgansky;A. Montecinos;V. Villagran;S. Metzger
本文报道了2009年1月(南夏)南美洲阿塔卡马沙漠北部大气沙尘暴的野外观测(≈20◦S)。观测到研究地点上空极高水平的沙尘暴活动，这取决于当地的气象条件。我们发现沙尘暴发生频次与由气象梯度计算的奥布霍夫尺度L高度相关，且随−L的减小有明显的增加趋势。−L≈20-30m和2-m平均风速V2≈8m S−1是沙尘暴发生的上限值，但没有观察到最小V2阈值。并行的常规气象测量使我们能够计算地表能量平衡的主要组成部分，获得地表反照率的直接估计(太阳中午的α≈为0.21)，并总结当地情况。
We report on field observations in January 2009 (austral summer) of atmospheric dust devils in the northern part of the Atacama Desert in South America (≈20◦S). An extremely high level of dust-devil activity over the study site has been observed, dependent on local meteorological conditions. We found a high correlation between the dust-devil frequency of occurrence and the Obukhov length scale, L, calculated from meteorological gradient measurements, with a clear tendency for this frequency to increase with decreasing −L. The upper threshold values of −L ≈ 20–30 m, and the 2-m mean wind speed, V2 ≈ 8m s−1, for dust-devil occurrence have been found, but the minimal V2 threshold was not observed. Parallel routine meteorological measurements enabled us to calculate the main constituents of the surface energy balance, to obtain direct estimates of the surface albedo (α ≈ 0.21 at the solar noon) and to summarize the local conditions.