利用中壢特高頻雷達研究降水激發大氣重力波

Using Chung-Li VHF radar to Study atmospheric gravity waves exciting by precipitation.

白劍鴻(Chien-hung Pai)

指導教授 ： 朱延祥

國立中央大學/地球科學學院/太空科學研究所/碩士(2007年)

摘要

研究重力波的重要議題之一，是探討激發重力波的能量源與其激發的機制，而VHF特高頻雷達擁有較佳的時間、空間解析能力，與同時觀測降水與大氣回波的特性，使VHF成為在降水環境中研究降水因素對大氣波動影響的良好工具。
本研究於2000年7月9月啟德颱風，經過台灣地區時利用中壢VHF特高頻雷達觀測發現，啟德颱風在向北前進時，其上下層之颱風結構是呈現傾斜，且與地面之傾角約15至27度，而颱風向北移動也會造成風向轉變上的干擾；在啟德颱風強烈的降水中，可以發現亂流混合作用增大，而造成的大氣回波功率衰減現象；也發現了降水粒子衝擊低層大氣，激發重力波向上傳播。

關鍵字

中壢特高頻雷達 ； 降水 ； 重力波

並列摘要

One of the most important topics in researching atmospheric gravity waves is to discussing the energy source of the waves and the mechanicism of excitation。
Owing better resolution of time-space and the capability to detect the echoes from precipitation and clear air, the VHF radars became good researching tool for study atmospheric waves in precipitating environment.
This research using Chung-Li VHF radar as a researching tool has found that when Tai-kei typhoon moving northward, she has tilted up a 15°-27° angle from the surface of the earth, and she disturbed the change of wind direction. It is also found that the depletion of the air echoes, because the increasing of turbulence mixing effect. Finally,it is found that the precipitation particles do excite gravity waves propagating upward.

並列關鍵字

gravity wave ； Chung-Li VHF radar ； precipitation

參考文獻

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Chu,Y.H.,and C.H.Lin,The severe depletion of turbulent echo power in association with precipitation observed by using Chung-Li VHF Radar, Radio Science, 29, 1311-1320, 1994.