The meandering margin of the meteorological moist Tropics
The meandering margin of the meteorological moist Tropics
复制标题
气象湿润热带的蜿蜒边缘
DOI：
10.1002/2017gl076440
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
and C. S. Velden
中科院分区：
文献类型：
--
作者：
Mapes;B. E.;E.-S. Chung;W. M. Hannah;H. Masunaga;A. J. Wimmers;and C. S. Velden
双峰分布的柱体水汽（CWV）表明热带地区存在一个明确的湿润状态，在当前气候条件下高于48 kg m− 2的边界值（约为柱饱和度的80%）。地图显示，这一边缘是一个蜿蜒曲折的天气轮廓，界定了广阔的高原潮湿的制度。在这些高原中，对流风暴的明显较小的对流和中尺度零星发生。尽管粗略的平均化，但整个极地最边缘的卫星数据合成显示其尖锐性：降水在100公里内翻了一番，其特点是云量增加和加深。输送的补丁和细丝的潮湿制度造成相应的降水事件内和以外的热带地区。通过一种新的基于卫星的拉格朗日CWV趋势估计，可以区分越过边缘的天气流和越过边缘的天气流。气候模式不能可靠地再现观测到的双峰分布，因此研究潮湿模式的维持过程和边缘区气团的转换，由拉格朗日趋势产品指导，可能会重要地限制模式潮湿过程的处理。
Bimodally distributed column water vapor (CWV) indicates a well‐defined moist regime in the Tropics, above a margin value near 48 kg m−2in current climate (about 80% of column saturation). Maps reveal this margin as a meandering, sinuous synoptic contour bounding broad plateaus of the moist regime. Within these plateaus, convective storms of distinctly smaller convective and mesoscales occur sporadically. Satellite data composites across the poleward most margin reveal its sharpness, despite the crude averaging: precipitation doubles within 100 km, marked by both enhancement and deepening of cloudiness. Transported patches and filaments of the moist regime cause consequential precipitation events within and beyond the Tropics. Distinguishing synoptic flows thatcrossthe margin from flows thatmovethe margin is made possible by a novel satellite‐based Lagrangian CWV tendency estimate. Climate models do not reliably reproduce the observed bimodal distribution, so studying the moist mode's maintenance processes and the margin‐zone air mass transformations, guided by the Lagrangian tendency product, might importantly constrain model moist process treatments.