由都卜勒鳳場反演三維熱動力場的可行性研究—以臺灣地區颮缐個案為例

The Feasibility of Retrieving Three-Dimensional Thermodynamical Structure from Doppler Wind Measurements-A Case Study of a Squall Line in taiwan Area

鐘高陞(Kao-Shen Chung) ； 廖宇慶(Yu-Chieng Liou) ； 陳臺琦(Tai-Chi Chen Wang)

《大氣科學》 30卷4期 (2002/12) Pp. 313-329

摘要

本研究採用Liou(2001)所提出的反演方法，由都卜勒風場反演三維的熱動力場，並使用1987年Taiwan Area Mesoscale Experiment(TAMEX)實驗期間Intesity Observation Period(IOP)#2一個颮線系統的雷達觀測資料來探討此方法的可行性。
比較本反演方式與傳統反演的方法發現，由於後者反演出來的是熱力場擾動量相對於水平平均的偏差量，在不知道每一層水平平均值的情形下，傳統方式反演所得的結果，垂直結構可能不正確而造成解釋分析上的錯誤。發展本方法之目的就是在嘗試改善這個限制。
藉由可信度參數(reliability parameter)、地面測站的觀測資料、斜溫圖、物理解釋上的合理性以及比較過去數值模擬對颮線的研究等種種間接證據證明，此反演方式可以應用到真實個案，對於瞭解中尺度天氣系統有一定的幫助。

關鍵字

都卜勒雷達 ； 勢動力反演 ； 變分法 ； 颮缐

並列摘要

This research presents a new method whereby one can apply the variational technique to momentum equations and thermodynamic equation, and simultaneously retrieve three-dimensional pressure and potential temperature distributions from Doppler wind measurements.
The newly designed method is utilized to study a squall line system observed during TAMEX IOP#2. The major focus is placed on the structure of the pressure gradient force, buoyancy force, and net acceleration along the vertical direction. It is also found in some vertical cross sections that the traditional thermodynamic retrieval algorithm may lead to erroneous interpretation of the thermodynamic field.
The validity of the retrievals is decided based on the reliability parameter, TAMEX surface observation, pre-squall sounding data at Makung, as well as the conceptual model of a squall line.

並列關鍵字

Doppler Radar ； Thermodynamic retrieve ； Variational technique ； Squall line