Impact of the inflow moisture on the evolution of a warm conveyor belt
Impact of the inflow moisture on the evolution of a warm conveyor belt
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DOI：
10.1002/qj.2360
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发表时间：
2015
影响因子：
8.9
通讯作者：
A. Schäfler;F. Harnisch
中科院分区：
文献类型：
--
作者：
A. Schäfler;F. Harnisch
这一案例研究的暖传送带（WCB）事件，是在研究飞行期间探测的THORPEX（观测系统研究和可预报性实验）太平洋亚洲区域运动（T-PARC）现场实验在2008年，调查的敏感性预测的WCB，相关的气旋和下游波导的入流区域的水分含量的WCB。通过同化的差分吸收激光雷达（DIAL）的水汽廓线到欧洲中期天气预报中心（ECMWF）综合预报系统（IFS），在分析领域的流入水分进行调整和湿度降低在一个广泛的区域周围的飞行轨迹。在WCB入流的初始减少的水分影响潜热释放沿着WCB，以及在较低的水平位涡（PV）的生产。这一变化导致预测的WCB流出高度大幅降低。此外，对流层顶高度降低至20百帕，导致下游急流风速变化高达15%。虽然对发展中的表面气旋的影响很小，但可以确定PV结构和动能的改进。
This case study of a warm conveyor belt (WCB) event that was probed on a research flight during the THORPEX (The Observing‐System Research and Predictability Experiment) Pacific Asian Regional Campaign (T‐PARC) field experiment in 2008, investigates the sensitivity of the forecast of the WCB, the associated cyclone and the downstream waveguide to the moisture content in the inflow region of the WCB. By assimilating water vapour profiles of a differential absorption lidar (DIAL) into the European Centre for Medium Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS), the inflow moisture in the analysis fields is adjusted and humidity is reduced in a broad region around the flight track. The initial reduction of moisture in the WCB inflow affects the latent heat release along the WCB, as well as the potential vorticity (PV) production at lower levels. This change led to a substantially lower outflow height of the forecasted WCB. Further, the height of the tropopause was reduced up to 20 hPa, which caused a change in the jet stream wind speeds of up to 15% downstream. Although the impact on the developing surface cyclone was small, improvements of the PV structure as well as of the kinetic energy could be identified.