English  |  正體中文  |  简体中文  |  Items with full text/Total items : 67783/67783 (100%)
Visitors : 23140574      Online Users : 358
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version

    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/73850

    Title: 台灣中部山區局部環流結構特性與其對空氣汙染物傳送過程的影響;Local circulations and their subsequent impact on air pollutants dispersion in Central mountainous region of Taiwan
    Authors: 林佳瑩;Lin, Chia-Ying
    Contributors: 大氣科學學系
    Keywords: 山區局部環流;空氣汙染物傳送;local circulation;air pollutant dispersion
    Date: 2017-08-22
    Issue Date: 2017-10-27 12:26:39 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 埔里盆地位於台灣中部山區,周圍的地形較複雜,在弱綜觀的大氣環境下,若有高污染事件發生,大氣污染物容易經由海風從西半部傳送至山區,造成埔里盆地的空氣品質變差。山區的局部熱力環流,如上下坡風、山谷風環流,以及邊界層的發展也會影響污染物擴散與累積。因此,本篇利用高解析中尺度氣象模式(WRF)以及地面測站資料來探討(1)埔里盆地熱力環流結構與邊界層發展特性,與(2)山區環流與海陸風的交互作用,以及(3)局部環流和邊界層發展對空氣污染物傳送的影響。


    ;Puli basin is located in central mountainous area of Taiwan. The thermally driven circulations such as the upslope/downslope wind and mountain/valley wind generally develop when the synoptic forcing is weak. During high PM2.5 concentration episode, air pollutants mainly produced in the western coastal region can be transported into inland area by sea breeze, and the air quality becomes bad in Puli basin. Air pollutants dispersion is strongly associated with local circulations and atmosphere PBL structure.

    In this study, the thermally driven circulations and its subsequent influence on the PBL structure and air pollutant dispersion Puli basin are investigated by using high-resolution mesoscale meteorological model (WRF) and observation data from the Central Weather Bureau (CWB) and air quality monitoring station of Environmental Protection Administration (EPA) in Taiwan.

    The upslope winds develop because of the different heating between sloping surface and adjacent plain and leads to the wind divergence and subsidence over the basin in the morning. With the onset of valley wind, the wind speed increase and westerly flow dominate over the basin. Additionally, the atmosphere turns stable to well-mixed condition quickly due to the solar heating and subsiding warming. On the other hand, the radiative cooling and cold air advection produced by downslope and mountain winds form the inversion layer during the night. The surface layer is decoupled from the flow above. Besides, the sea breeze penetrates into mountainous region in the afternoon. The mountain wave is induced by the interaction between the sea breeze and topography. The wind speed increase because of the combination of sea breeze and valley winds.

    According to observation data from EPA and CMAQ model results, air pollutants are mostly produced in the western plain and transported by the sea breeze into mountainous region. And the PM2.5 concentration observed at Puli station raise sharply in the afternoon. The inversion layer associated with the radiative cooling and cold air advection forms and causes pollutants accumulate near the surface. With the onset of the mountain wind, the pollutants tend to be transported plainward and the PM2.5 concentration recorded at Puli station decrease. After sunrise, the convective boundary layer develops, the vertical mixing becomes strong and dilutes the concentrations near the surface.
    Appears in Collections:[大氣物理研究所 ] 博碩士論文

    Files in This Item:

    File Description SizeFormat

    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明