Interpretation of Satellite Imagery of A Rapidly Deepening Cyclone
Interpretation of Satellite Imagery of A Rapidly Deepening Cyclone
复制标题
快速增强气旋的卫星图像解读
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
K. Browning
中科院分区：
文献类型：
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作者：
M. Young;G. Monk;K. Browning
模式输出和观测数据被用来详细解释一个数百公里长的独特云系的卫星图像，该云系是在英格兰上空发生的气旋快速发展之前和期间观测到的。提出的概念模型说明了主要云区和高层湿度场的结构(如水蒸气图像所观察到的)，这些结构紧接在强烈的气旋发生开始之前和之后。
这个云系相当于R.B.韦尔登所说的斜压叶云，其特征是冷锋上升。斜压叶位于一个主要的高层低谷之前的增强上升区域内。起源于上游的急流条纹在高空槽底部附近迅速传播。集中在这条急流的左侧的一股干燥空气舌正好位于叶云的上游，并对随后的发展产生了重大影响。气象局的精细网格模式很好地描述了这种干空气的入侵，该模式显示它是最近下降的具有高位涡的空气的明显舌状物，起源于对流层上部和平流层下部。在叶云南端温暖的传送带内，干入侵压过高θw的低层空气时，发生了快速的气旋发生。干入侵和斜压叶云的相互作用在解释天气的详细分布方面特别重要。它还提出了一种精确定位强回旋发生的位置和时机的方法。
Model output and observational data are used to interpret, in detail, satellite images of a distinctive cloud system several hundred kilometres long which was observed before and during rapid cyclonic development that occurred over England. Conceptual models are forwarded which account for the structure of the major cloud areas and upper-level moisture fields (as observed by water vapour imagery) immediately prior to and following the onset of vigorous cyclogenesis.
The cloud system corresponded to what R. B. Weldon refers to as a baroclinic leaf cloud and was characterized by ‘ana’ cold frontal ascent. the baroclinic leaf lay within an area of enhanced ascent ahead of a major upper-level trough. A jet streak which originated upstream, propagated rapidly around the base of the upper trough. A tongue of dry air centred on the left flank of this jet streak lay immediately upstream of the leaf cloud and had a major influence on its subsequent development. This intrusion of dry air was well represented by the Meteorological Office fine mesh model, which showed it as a pronounced tongue of recently descended air with high potential vorticity, which originated in the upper troposphere and lower stratosphere. Rapid cyclogenesis occurred as the dry intrusion overran low-level air of high θw within a warm conveyor belt at the southern tip of the leaf cloud. Interaction of the dry intrusion and baroclinic leaf cloud is shown to be particularly important in accounting for the detailed distribution of weather. It also suggests a way of pinpointing the location and timing of vigorous cyclogenesis.