Numerical simulations of the decay of Martian global dust storms
Numerical simulations of the decay of Martian global dust storms
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火星全球沙尘暴衰减的数值模拟
DOI：
10.1029/jb095ib09p14629
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发表时间：
1990
影响因子：
--
通讯作者：
J. Pollack
中科院分区：
文献类型：
--
作者：
J. Murphy;O. B. Toon;R. Haberle;J. Pollack
研究了火星全球性（大）沙尘暴的衰减。一维（垂直，静态大气）和二维（纬度-高度，稳态环流）模拟进行气溶胶传输微物理模型表明，大气运动中发挥了重要作用，在观察到的全球沙尘暴的衰减。1971年的宇宙飞船观测（水手9号，维京海盗号）和1977年的两次行星环绕沙尘暴提供了关于风暴衰减的一些特征的建议。具体而言，尘埃粒子的大小分布被推断为保持基本不变的粒子半径在1和10 μm之间的衰减的1971年风暴，和表面可见光不透明度下降的准指数随时间在北方中纬度地区的两个1977年风暴的衰减。研究结果表明，二维和三维动力学过程在观测到的火星全球沙尘暴衰减特征中起着重要作用。最重要的过程是在南半球亚热带地区的沙尘源区通过垂直运动产生的沙尘和大气沙尘向北方沙尘汇区的持续平流再补给。我们的工作有影响的维京海盗数据分析和未来的火星观测者的意见，并要求作为一个时间和纬度依赖的量的颗粒大小分布被视为。
The decay of Martian global (great) dust storms is investigated. One-dimensional (vertical, static atmosphere) and two-dimensional (latitude-height, steady state circulation) simulations carried out with an aerosol transport-microphysical model indicate that atmospheric motions play a significant role in the observed decay of global dust storms. Spacecraft observations (Mariner 9, Viking) of the 1971 and the two 1977 planet-encircling dust storms have provided suggestions about some characterisrics of storm decay. Specifically, the dust particle size distribution is inferred to have remained essentially unchanged for particles with radii between 1 and 10 μm during decay of the 1971 storm, and surface visible opacity declined quasi-exponentially with time in northern mid-latitudes during the decay of the two 1977 storms. The results from this investigation indicate that two- and three-dimensional dynamical processes play a significant role in the observed decay features of Martian global dust storms. The most important processes are the lofting of dust by vertical motions in the dust source region of the southern hemisphere subtropics and a continuing advective resupply of atmospheric dust into the dust sink regions of the northern hemisphere. Our work has implications for Viking data analyses and future Mars observer observations and requires that the particle size distribution be treated as a time and latitude dependent quantity.