Observations of Elevated Convection Initiation Leading to a Surface-Based Squall Line during 13 June IHOP_2002
Observations of Elevated Convection Initiation Leading to a Surface-Based Squall Line during 13 June IHOP_2002
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DOI：
10.1175/2010mwr3422.1
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发表时间：
2011
影响因子：
3.2
通讯作者：
J. Marsham;S. Trier;T. Weckwerth;James W. Wilson
中科院分区：
文献类型：
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作者：
J. Marsham;S. Trier;T. Weckwerth;James W. Wilson
摘要描述了在美国大平原上进行的国际水计划期间观测到的一个中尺度对流系统（MCS）的演变过程。MCS在夜间形成于锋区，在当地时间0000和0400之间发生了四次初始事件。雷达，无线电探空仪，和地面数据一起显示，至少有三个初始事件被抬高，发生在潮湿的条件不稳定层位于边界层之上，这已经稳定了以前的MCS。开始出现在西北-东南方向的线，在那里一个偏南的夜间低空急流终止，产生升高的辐合。使用S波段双偏振多普勒雷达（S-Pol）观察到一个初始事件，并发生在该会聚区与传播波的交叉点处。Scorer参数的计算与波捕获一致。对流发展产生的下沉气流既产生波又产生孔，从而导致了对流的发展。
Abstract The evolution of a mesoscale convective system (MCS) observed during the International H2O Project that took place on the Great Plains of the United States is described. The MCS formed at night in a frontal zone, with four initiation episodes occurring between approximately 0000 and 0400 local time. Radar, radiosonde, and surface data together show that at least three of the initiation episodes were elevated, occurring from moist conditionally unstable layers located above the boundary layer, which had been stabilized by previous MCSs. Initiation occurred in northwest–southeast-oriented lines where a southerly nocturnal low-level jet terminated, generating elevated convergence. One initiation episode was observed using the S-band dual-polarization Doppler radar (S-Pol) and occurred at the intersection of this convergence zone with a propagating wave. Calculations of the Scorer parameter were consistent with wave trapping. Downdrafts from the developing convection generated both waves and bores, w...