大气科学2013，Vol.37Issue(4)：786-800,15.DOI:10.3878/j.issn.1006-9895.2012.12114
钟形地形动力抬升和重力波传播与地形云和降水形成关系研究
Relationship between Bell-Shaped Terrain Dynamic Forcing, Mountain Wave Propagation, and Orographic Clouds and Precipitation
摘要
Abstract
Orographic clouds and precipitation have a critical role in regional water cycles,fresh water resources,ecosystems,the environment,and climate change.The relationship between terrain dynamic forcing,mountain waves,orographic clouds and precipitation,and the formation mechanism were investigated in a conditionally unstable moist atmosphere on May 1,2009,by using the Weather Research and Forecasting (WRF) Model and the wet Froude number (Fw).The results show that at a topographic height of 2 km and half-width of 10 km,when unstable airflow gradually increases from 2.5 to 25 m/s,the wet Froude number increases from 0.19 to 1.81.The terrain block has a major role when Fw≤ 1; orographic clouds induced by terrain dynamic lifting form on the windward side,and mountain waves form mainly over the windward side and propagate toward the upstream region,which forms stratiform clouds at first and then evolves as quasi-stable shallow convective wave clouds.The maximum precipitation occurs at the terrain crest near the windward side.When Fw is too small,no precipitation is produced.When Fw＞ 1,the orographic clouds induced by terrain dynamic lifting form primarily at the terrain crest,and mountain waves form mainly over the leeward side and propagate toward the region downstream of the crest,producing quasi-stable shallow convective wave clouds in the downstream region.In addition,in a weak and conditionally unstable moist atmosphere,orographic precipitation is produced mainly by warm microphysical processes induced by terrain lifting,and mountain wave clouds cannot produce precipitation.关键词
湿条件不稳定层流/地形云和降水/地形重力波传播/北京Key words
Conditionally unstable moisture airflow/ Orographic clouds and precipitation/ Mountain wave/ Beijing region分类
天文与地球科学引用本文复制引用
郭欣,郭学良,付丹红,牛生杰..钟形地形动力抬升和重力波传播与地形云和降水形成关系研究[J].大气科学,2013,37(4):786-800,15.基金项目
国家自然科学基金资助项目41005072、40575003,国家科技支撑计划重点项目03课题2006BAC12B03 （）
