原名「台灣學術線上」
包含TAO期刊庫 + TAO書籍庫 + 論文 + 史料文獻
首頁 | 關於TAO | 瀏覽 | 進階查詢 | 參考工具 | 會員服務 | 已購專書 | RSS服務 | 電子報 | FAQ  
查詢範圍:
   
查詢模式:
熱門查詢詞:
   
   
   
     
   
 
項次 書目
1
題名:東亞沿海地區爆發性氣旋之合成分析     (66點)
A Composite Study of Explosive Coastal Cyclones Over East Asia
著者:林松錦(Song-Chin Lin) ;王碧霞(Bih-Shya Wang)
出版地區:台灣
出版城市:台北市
學科:天文學 ; 地球科學
關鍵字:旋生 ; 爆發性氣旋 ; Cyclogenesis ; Explosive Cyclone
刊名:大氣科學
卷期:22期1號(1994.3)
頁碼:23-55
語言:繁體中文
摘要: 中文摘要PDF ; 英文摘要PDF

本文選取1980~1990年間發生在東海鄰近臺灣附近海域,海平面氣壓下降率大於1.5 bergerons的12個爆發性氣旋個案做合成分析。採用ECMWF資料,以500 hPa的相對渦度極大?位置?中心,切取的40°×40°經度/緯度的移動性合成方盒,來做合成氣旋的分析。資料時間間隔?12小時,分析在最大氣壓下降前36小時及後24小時內合成氣旋的水平及垂直結構,並探討大尺度環流對氣旋系統發展的影響。 分析結果顯示,在氣旋爆發前36小時至後24小時中,500 hPa均伴隨有明顯的相對渦度極大?存在。在氣旋發展初期,500 hPa的高度槽位於地面氣旋的西方,系統向西傾斜,斜壓性顯著,而氣旋中心附近之低層條件性不穩定度隨氣旋發展有增加之趨勢。至爆發後期,500 hPa的高度槽逐漸趕上地面氣旋,此時中層的大氣結構己和地面氣旋結合,氣旋?暖心結構。 由水平風場、垂直運動場及相對渦度場的水平分佈情形得知,合成氣旋的發展高度僅達500hPa,300 hPa的強渦度場乃高層噴流所引起,而非氣旋本身的垂直環流所致,此合成氣旋?一淺系統。但高層噴流出區之熱力間接環流所造成的高層輻散,是引發氣旋急速發展的有利環境。由渦度方程及等壓座標之位渦分析得知,在氣旋發展的初期及爆發期的前12小時,氣旋式渦度的增強,在低層主要是輻合的貢獻,而在中層垂直渦度平流有較大的貢獻;在爆發期的後12小時,水平渦度平流的貢獻則顯著增強。在氣旋發展初期,於地面氣旋上游有高層的高位渦空氣往低層注入。此外,由水汽輻合分析發現,在700-500 hPa間的上升運動區?水汽輻合區,下降運動區?水汽輻散區,顯示合成氣旋的上升運動與潛熱釋放有明顯關連。
In this study, twelve cases of explosive cyclones (with central sea-level-pressure deepening rate larger than 1.5 bergerons) occurring over the East Sea near Taiwan during 1980-1990 were selected to perform composite analysis. A 40°×40° latitude/longitude compositing box with 500 hPa relative vorticity maximum as the center of this compositing box is defined to investigate the composite structure and mean characteristics of explosive cyclones during the cyclone's development (36 hours before and 24 hours after the maximum pressure deepening time). The data utilized are ECMWF's analyses with 12 hours' interval. The results show that a distinguish 500 hPa relative vorticity maximum can be seen in association with the cyclone's development. The incipient cyclone mainly caused by low-level instability is characterized by prominent baroclinicity with 500 hPa trough tilted to the west of the surface cyclone. The 500 hPa trough becomes in phase with the surface cyclone as the warm-core cyclone deepens explosively. The relative vorticity and three-dimensional wind analyses reveal that the composite cyclone is a shallow system with vertical extent up to 500 hPa level only. The 300 hPa strong cyclonic vorticity is a part of the secondary circulation of the upper-level jet stream. However, the strong upper-level divergence of the indirect circulation at the left-front region of the upper-level jet stream is a favorable condition for the explosive deepening of the surface cyclone. The vorticity budget and the isobaric potential vorticity analyses also reveal that the increasing of cyclonic vorticity during the antecedent development is due to convergence in the lower levels and vertical vorticity advection in the middle levels. At the explosive stage, horizontal vorticity advection is the major contribution to the increasing of cyclonic vorticity. At the upstream to the west of surface cyclone, downward intrusion of high potential vorticity air can be seen in the upper levels as the cyclone begins to deepen explosively. In 700-500 hPa layer, moisture convergence can be seen in region of upward vertical motion in association with the surface cyclone, which indicates the significance of latent heat release to the development of the explosive cyclone. Thus, in addition to the low-level baroclinic instability, latent heat release and upper-level large scale forcing could also be important to the development of explosive cyclones occurring over the East Sea.


    

本卷期目次
大氣科學 22期1號 (1994.3)
正定義數?方法的探討/ 郭鴻基柳再明
台灣西北海岸夏初背景SO2與CO測量與分析/ 柳中明羅俊光左台利王作臺徐光蓉
臺灣梅雨季初期南亞高層反氣旋之演化研究/ 柯文雄鄧博元
東亞沿海地區爆發性氣旋之合成分析/ 林松錦王碧霞
氣象環流對背景大氣成份傳送影響:第一部份:軌跡方法之建立及個案分析結果/ 王作臺胡志文林松錦柳中明
東亞地區不同強度寒潮爆發過程動力結構之比較/ 江火明彭穎聖
 
   
 
   

與TAO合作 | 隱私與版權聲明 | 聯絡方式 | 下載Adobe Reader
地址:台北市中正區(100)北平東路30-12號3樓
電話:(02)2393-6968 傳真:(02)2393-6877
Email: service@wordpedia.com
Wordpedia Family: 學校、企業版入口 | 遠流影音館
Copyright©2011 Wordpedia Co., Ltd. All Rights Reserved.