A Diagnostic Model for Estimating Orographic Precipitation
A Diagnostic Model for Estimating Orographic Precipitation
复制标题
估算地形降水量的诊断模型
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
M. Sinclair
中科院分区：
文献类型：
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作者：
M. Sinclair
摘要本文提出了一个估算详细地形降水量的简单模式。该模型初始化使用欧洲中期天气预报中心的粗分辨率分析，并适用于新西兰北方热带气旋博拉（1988年3月）的暴雨。该模型基于地形强迫垂直运动的估计，即V·zs，其中zs是地形的高度，V是山脉上游的水平流。通过计算模式结果与297个雨量计测量结果的相关系数rg来评估模式的技巧。通过增加背风干燥、风漂移效应以及大尺度湿度和垂直运动场的调制来增强模型，每个都导致rg在统计上显著增加。最好的结果是在分辨率接近10公里，其中获得的rg为0.84。然而，在25公里分辨率下忽略漂移效应导致模型技能几乎等同于完整模型。
Abstract A simple model for estimating detailed orographic precipitation is presented. The model is initialized using coarse-resolution analyses from the European Centre for Medium-Range Weather Forecasts and is applied to the heavy rainfall over northern New Zealand from Tropical Cyclone Bola (March 1988). The model is based on the estimation of topographically forced vertical motion as V·∇zs, where zs is the height of the topography and V is the horizontal flow just upstream of the mountain. Model skill is evaluated by computing the correlation coefficient rg of the model results against 297 rain gauge measurements. Enhancement of the model by adding lee drying, wind drift effects, and modulation by larger-scale humidity and vertical-motion fields each led to a statistically significant increase in rg. Best results were obtained at a resolution near 10 km, for which an rg of 0.84 was obtained. However, ignoring drift effects at 25-km resolution resulted in model skill nearly equivalent to the full model...