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105/05/10 14:00 臺灣大學大氣科學系游政谷教授 演講
演講公告
張貼人：網站管理員 ╱ 公告日期：2016-05-04演 講 公 告
主講人：游政谷 教授
地點：中央大學科學一館S-325教室
摘要：
講題：Wintertime Orographic Precipitation over Mt. Da-Tun
主講人：游政谷 教授
臺灣大學大氣科學系
時間：05月10日（星期二）下午2點
地點：中央大學科學一館S-325教室
摘要：
Mt. Da-Tun (DT) is located immediately adjacent to the northern coast of Taiwan and frequently produces the rainfall maximum as wintertime northeasterly monsoon flow interacts with the mountain barrier. With the complement of special rain gauge observing network deployed over the mountainous region of DT, which can provide high temporal and spatial resolution of surface rainfall measurements, this study documents unique aspects of orographic rainfall and their underlying mechanisms. In this study, twenty-two wintertime rainfall events associated with northeasterly monsoon flow during the period from January 2011 to February 2014 were chosen for detailed analysis. Upstream conditions associated with the studied events were characterized by nearly neutral convective instability, large Froude number, and moist northeasterly oncoming flow. Local maxima of orographic precipitation were observed to occur mostly over the windward slopes and/or near the mountain crest. The precipitation distributions were found to be generally consistent with the forcing of upslope lifting, as verified by a diagnosis model of orographic precipitation. In addition, one of the most interesting findings from the study is that a few of the studied cases exhibited the rainfall maximum located within the windward valley region. The degree of the precipitation enhancement over the valley region appears to depend strongly on the wind direction of upstream prevailing flow. The possible mechanism responsible for this observed feature of precipitation will be also discussed and presented in this talk.
最後修改時間：2016-04-28 AM 10:38
