文化大學機構典藏 CCUR:Item 987654321/33520
English  |  正體中文  |  简体中文  |  全文笔数/总笔数 : 46965/50831 (92%)
造访人次 : 12649113      在线人数 : 583
RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
搜寻范围 查询小技巧：
  • 您可在西文检索词汇前后加上"双引号"，以获取较精准的检索结果
  • 若欲以作者姓名搜寻，建议至进阶搜寻限定作者字段，可获得较完整数据
    •  进阶搜寻
    主页 ‧ 登入 ‧ 上传 ‧ 说明 ‧ 关于CCUR ‧ 管理 到手机版


    jsp.display-item.identifier=請使用永久網址來引用或連結此文件: https://irlib.pccu.edu.tw/handle/987654321/33520


    题名: 利用再分析資料重新估計粗濕穩定度
    Evaluation of the tropical gross moist stability using modern data
    作者: 張偉軍
    贡献者: 地學研究所大氣科學組
    关键词: 大氣粗濕穩定度
    大氣粗濕分層度
    熱帶深對流
    Gross moist stability
    Gross moisture stratification
    Tropical deep convection
    日期: 2016-06
    上传时间: 2016-08-11 11:18:33 (UTC+8)
    摘要: 近年來，有許多研究間接利用粗濕穩定度(Yu 1997)研究氣候現象，如Madden-Julian Oscillation(MJO)。粗濕穩定度是由深層大氣對流的濕靜能剖面來決定，這指標可以用來顯示大氣的狀態與改變。
    本研究主要是藉由不同的在再析資料與International Satellite Cloud Climatology Project的雲頂氣壓資料(簡稱ISCCP)來分析粗濕穩定度。在氣候平均上，粗濕穩定度在熱帶地區一般而言是為正值，且其水平梯度小。原本粗濕穩定度地飽和高度是1000hPa，而本研究則利用氣塊法測試幾種不同飽和測試粗濕穩定度的影響並以觀測資料檢驗。飽和高度與最大對流高度對粗濕穩定度的影響很大，其中以自由對流高度當飽和高度所計算出的濕穩定度值小，呈現負值，對流厚度(積分範圍)縮小25~30%。飽和高度是位於低對流層中，大多數的水氣分布其中，飽和高度越高，最大對流高度越高，粗濕穩定越小；反之亦然。
    就ISCCP資料對比假設的最大對流高度分析結果，可以得知最大對流高度的假設整體而言是小於ISCCP的雲頂(ISCCP高度較低)，其中西太平洋差異較小，東太平洋差異較大。根據Raymond (2009)標準化濕穩定度(normalized gross moist stability，簡稱NGMS)，水氣潛能方程式可以用來直接或間接檢驗粗濕穩定度。直接檢驗方式的結果為，濕穩定與水氣潛能的比值較NGMS平緩。就間接檢驗方式的結果分析，可以得知垂直項的空間分布類似於觀測，但整體而言垂直項的結果大於觀測，且東太平洋的誤差最大。
    In recent years, many studies have indirectly use gross moist stability (Yu 1997) to analyze climatic phenomena (e.g., Madden-Julian Oscillation, MJO). The gross moist stability is determined by atmospheric most static energy profile associated with the depth of convection. This index is used to display atmospheric stability and change.
    The main purpose of this study is to use reanalysis data and International Satellite Cloud Climatology Project (ISCCP) data to examine gross moist stability. In climatic mean, it is found that gross moist stability is positive and its gradient is small in the tropics. In the original way of estimating gross moist stability, the saturated layer is assumed at 1000hPa. In this study, several different saturation levels are used to estimate gross moist stability and compare with observational data. The results show that the saturation level and the maximum height of convection are important to the estimate of gross moist stability. Minimum values occur when the level of free convection is chosen as the saturation level.
    Because the maximum height of convection is idealized, the difference between the maximum height of convection and ISCCP data is large in generally. In the western Pacific convergence zone, the differences range from 100hpa to 150hpa. In the eastern Pacific convergence zone, the differences range from 300hpa to 350hpa. According to the normalized gross moist stability (Raymond 2009, NGMS), the moisture budget equation is used to examine gross moist stability. The results show that ratio of gross moist stability over gross moisture stratification (Mq) is smoother than NGMS in the Pacific convergence zone. In analysis by using moisture budget equation, we found that while the vertical moisture advection term is in general balanced by the difference between rainfall and evaporation, but the errors are large.
    显示于类别:[大氣系所] 博碩士論文

    文件中的档案:

    档案 描述 大小格式浏览次数
    index.html0KbHTML437检视/开启


    检视Licence

    在CCUR中所有的数据项都受到原著作权保护.

    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 回馈