Skip navigation

DSpace JSPUI

DSpace preserves and enables easy and open access to all types of digital content including text, images, moving images, mpegs and data sets

Learn More
DSpace logo
English
中文
  • Browse
    • Communities
      & Collections
    • Publication Year
    • Author
    • Title
    • Subject
  • Search TDR
  • Rights Q&A
  • Help
    • My Page
    • Receive email
      updates
    • Edit Profile
  1. NTU Theses and Dissertations Repository
  2. 理學院
  3. 大氣科學系
Please use this identifier to cite or link to this item: http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/64051
Title: 暖季降水系統雨滴譜及結構特徵分析研究
Characteristics of Raindrop Size Distribution and Structure of Warm Season Precipitation
Authors: Chi-June Ultimate Jung
鍾吉俊
Advisor: 周仲島
Keyword: 定量降水估計,回波降雨關係式,撞擊式雨滴譜儀,層狀/對流降水,雨滴粒徑分布,Gamma分布,回波垂直剖面,
Quantitative precipitation estimation (QPE),Z-R relationship,Joss-Waldvogel disdrometer,stratiform/convective precipitation,drop size distribution (DSD),gamma distribution,vertical profile of reflectivity (VPR),
Publication Year : 2012
Degree: 碩士
Abstract: 台灣位於副熱帶季風區,多變的天氣系統受地形影響,產生複雜的降水過程及雨量分布。地面雨量站在山區的數量有限且分布不均,雷達可提供高時空解析度的降雨系統資訊並進行定量降雨估計。然而,由於降雨系統多具有不均勻的雷達回波剖面,且雷達波束受地形遮蔽影響,常無法測得或是低估近地面的降雨回波。本研究在梅雨季和颱風季期間,於山區河谷及平地設置雨滴譜儀,結合雷達觀測,對於降水系統的雨滴粒徑分布特徵以及垂直結構進行分析研究。暖季的降雨形態可由降雨率時序標準差大小分類為對流性及層狀性降水,層狀降水發生比例較高,但總雨量的主要來源則是對流降水。山區對流降水的發生比例高於平地,對流降水對山區總雨量的貢獻也較平地大。分析雨滴粒徑分布參數可發現,對流降水的粒徑分布型態為Gamma分布且多為較大的雨滴,但層狀降水更趨近於負指數型態(或稱為Marshall- Palmer)分布並以較小的雨滴為主。實驗觀測所擬合的不同降雨類型的Z-R關係式彼此相近,但皆與現用於降雨估計之Z=32.5 R1.65差距甚大。應用平均降雨關係式為Z=216.4 R1.35,可有效修正平地降雨的高估。本文分析回波垂直剖面發現,平均回波隨高度降低而穩定增加,比較平均回波剖面的斜率絕對值,可以發現:山區大於平地、對流大於層狀;而降雨強度越強,斜率也越大。利用此特性將雷達回波外延修正至地面,應用於定量降水估計,可改善山區降雨低估情形達10%以上。分類不同降雨型態,應用不同斜率進行回波值外延,估計降雨更為準確。
In Taiwan, complicate rainfall process and distribution produced by the interaction of terrain and subtropical weather systems. Rain gauges are limited and non-uniform distributed in the mountains, and radar has the ability to provide higher time and space resolution of the precipitation system then quantitative precipitation estimation (QPE) is proceeded. However, non-uniform vertical profile of reflectivity (VPR) and beam blockage due to complex topography could result in the underestimation of reflectivity. To understand the precipitation characteristics near surface, ground-based disdrometers were deployed both in the mountains and in the coastal plain. The variation of drop size distributions (DSD) is used to classify convective versus stratiform precipitation. The statiform precipitation is the major contribution to the rainfall duration while the convective precipitation contributed to the most accumulation rainfall, and larger percentage of probability of convection was presented in mountain area than in plain. The convective DSD shows gamma distribution with more large drops and the stratiform DSD is much similar with the Marshall- Palmer distribution. Surface Z-R relationships which are derived via DSD show little difference between different topographies or different rainfall type, but all show large difference with currently used Z=32.5 R1.65. Mean surface Z-R relationship, Z=216.4 R1.35, helps to correct the underestimation of QPE in plain. The composited VPR for both convective and stratiform precipitation show increases below the melting level, both in mountain and in the plain regions. The extended VPRs and surface Z-R relationship were used to reexamine the QPE of several typhoons. The underestimation in the mountain area was improved about 10 %. We could have more accurate QPE if we consider different VPR for various precipitation types.
URI: http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/64051
Fulltext Rights: 有償授權
Appears in Collections:大氣科學系

Files in This Item:
File SizeFormat 
ntu-101-1.pdf
  Restricted Access
12.68 MBAdobe PDF
Show full item record


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

社群連結
聯絡資訊
10617臺北市大安區羅斯福路四段1號
No.1 Sec.4, Roosevelt Rd., Taipei, Taiwan, R.O.C. 106
Tel: (02)33662353
Email: ntuetds@ntu.edu.tw
意見箱
相關連結
館藏目錄
國內圖書館整合查詢 MetaCat
臺大學術典藏 NTU Scholars
臺大圖書館數位典藏館
本站聲明
© NTU Library All Rights Reserved