Mean Vertical Motions Seen by Radar Wind Profilers
Mean Vertical Motions Seen by Radar Wind Profilers
复制标题
雷达风廓线仪观测到的平均垂直运动
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
T. Vanzandt
中科院分区：
文献类型：
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作者：
G. Nastrom;T. Vanzandt
摘要雷达风廓线仪可直接测量雷达站上空的垂直运动。在山区和山区附近的观测点，对流层和平流层下部的垂直运动平均值通常为每秒几厘米，通常归因于准定常背风波的影响。然而，现在在远离任何山脉的平原地区进行的观测也显示出每秒几厘米的平均值。例如，伊利诺伊州香槟-厄巴纳附近的平地甚高频雷达观测到的月平均值在-3至-7 cm s-1之间，最大震级出现在冬季。作者检验了先前提出的几个解释这些观测结果的假设，发现每个假设在某些方面都与观测结果不一致，除了沿着沿着平缓倾斜的等熵面的准水平流动导致平均向下运动高达12 cm s−1。作者认为，在本文中，影响的…
Abstract Radar wind profilers have been used to measure directly the vertical motion above the radar site. Mean values of vertical motions in the troposphere and lower stratosphere reported at sites in and near mountains are often several centimeters per second and have often been attributed to the effects of quasi-stationary lee waves. However, observations now available at sites in the plains, far from any mountains, also show mean values of several centimeters per second. For example, monthly mean values seen by the Flatland VHF radar near Champaign-Urbana, Illinois, range from about −3 to −7 cm s−1, with largest magnitudes during the winter. The authors examine several of the hypotheses that have previously been advanced to explain these observations and find that each is inconsistent with the observations in some respect, except that quasi-horizontal flow along gently sloping isentropic surfaces leads to mean downward motion as large as 12 cm s−1. In this paper the authors suggest that the effects o...