- 期刊
TAMEX期間台灣海峽之水汽和能量收支
The Moisture and Energy Budgets over Taiwan Strait during TAMEX
摘要
梅雨期間，鋒面雲帶常伴隨著對流系統，帶給台灣地區連續性及陣性的降水，對流雲對於水汽與能量的垂直傳送扮演著重要的角色。本文利用Yanai et al.（1973）所定義之視熱源（Q1）和視水汽匯（Q2），採用TAMEX期的觀測資料，計算並探討台灣海峽的水汽與能量的收支。結果顯示，TAMEX期間台灣海峽對流系統之視熱源在中高對流層為最大加熱區，與熱帶地區對流系統類似；低對流層之加熱微弱甚至有冷卻現象，則與中緯度地區相似。當考慮砧雲區時，則中高對流層為上升運動，且Q1為正值，至於中下對流層則為下沈運動，並伴隨有負的Q1值。海面之蒸發以及水汽之水平輻合效應均為降水之重要水汽來源，但當對流系統發展時，除蒸發量明顯增加外，水平水汽輻合量大量增加，此結果顯示了西南暖溼平流在對流系統發展中所扮演的角色。
並列摘要
During the Mei-Yu season, convective systems are often imbedded in cloud bands associated with fronts, and always play an important role in the vertical transports of moisture and energy. By computing the Q1 (apparent heat source) and Q2 (apparent moisture sink) (Yanai et al., 1973), we analyze the moisture and energy budgets over Taiwan Strait during TAMEX period.Results reveals that the averaged Q1 profile of disturbed cases in Taiwan Strait appears to hold a vertical pattern similar to that of the tropical area with large heating at the middle-upper troposphere. However, there is a cooling effect below 700mb. This feature is more similar to the computed results of the mid-latitude systems. When appreciable anvil clouds are included in the computed area, the results show an upward motion and heating at middle to upper troposphere but a downward motion and cooling at middle to low levels. Our results also indicate that both large scale moisture convergence and the surface evaporation are important moisture sources in Taiwan Strait during TAMEX. However, within the convective region, the surface evaporation increases but the horizontal moisture convergence increases more greatly. The tremendous increase in horizontal convergence implies the important of the supplies of warm moist air by the strong southwesterly during the initiation stage of a convective system.