Microphysics of Maritime Tropical Convective Updrafts at Temperatures from -20° to -60°
Microphysics of Maritime Tropical Convective Updrafts at Temperatures from -20° to -60°
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DOI：
10.1175/2009jas3107.1
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发表时间：
2009-12
影响因子：
3.1
通讯作者：
A. Heymsfield;A. Bansemer;G. Heymsfield;A. Fierro
中科院分区：
文献类型：
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作者：
A. Heymsfield;A. Bansemer;G. Heymsfield;A. Fierro
强烈的热带对流产生的冰凌对地球的辐射平衡有重要贡献，其辐射特性在很大程度上取决于形成冰凌的冰粒的浓度和大小。这些微物理特性在很大程度上取决于在上升气流中悬浮的直径从3微米到20微米的过冷液滴的命运。目前的研究解决的问题是，这些液滴是否大部分或全部被冰粒捕获，或者它们是否一直未被收集，直到到达- 38°C的水平，在那里它们被均匀成核冻结，产生高浓度的非常小的冰粒，这些冰粒可以持续存在并主导反照率。本文结合25°N ~ 11°S纬度7次野外活动的飞机冰粒子和水滴尺寸分布数据，探讨了大量过冷水滴向均匀核沉降的条件。
Abstract Anvils produced by vigorous tropical convection contribute significantly to the earth’s radiation balance, and their radiative properties depend largely on the concentrations and sizes of the ice particles that form them. These microphysical properties are determined to an important extent by the fate of supercooled droplets, with diameters from 3 to about 20 microns, lofted in the updrafts. The present study addresses the question of whether most or all of these droplets are captured by ice particles or if they remain uncollected until arriving at the −38°C level where they freeze by homogeneous nucleation, producing high concentrations of very small ice particles that can persist and dominate the albedo. Aircraft data of ice particle and water droplet size distributions from seven field campaigns at latitudes from 25°N to 11°S are combined with a numerical model in order to examine the conditions under which significant numbers of supercooled water droplets can be lofted to the homogeneous nucl...