Investigating hygroscopic cloud-seeding effects in liquid-water clouds in northern Taiwan: in-situ measurements and model simulation

NCU Institutional Repository > 地球科學學院 > 大氣物理研究所 > 博碩士論文 > Item 987654321/89007

請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/89007

題名:	Investigating hygroscopic cloud-seeding effects in liquid-water clouds in northern Taiwan: in-situ measurements and model simulation
作者:	林凱翊;Lin, Kai-I
貢獻者:	大氣科學學系
關鍵詞:	吸濕性粒子種雲;雲微物理過程;競爭效應;尾巴效應;Hygroscopic particle seeding;cloud microphysical process;competition effect;tail effect
日期:	2022-07-14
上傳時間:	2022-10-04 10:47:36 (UTC+8)
出版者:	國立中央大學
摘要:	全球暖化導致乾旱之強度與頻率增加；於2021年，台灣亦面臨近百年來最為嚴重之乾旱，也因此促使政府嘗試發掘解決辦法，而吸濕性粒子種雲似乎為一種兼具可行性與可能性之方法，用以解決水資源匱乏之問題。本研究嘗試結合現地觀測與數值模擬，探究吸濕性氣膠種雲在種雲過程中所需要的環境條件及雲微物理變化特徵，針對北台灣集水區建立人工種雲與降雨的個案研究，並提出一個有效且具科學基礎的人工種雲策略。在2019-2021年期間，吾人針對台灣乾季共實施了4次東眼山種雲觀測實驗，建立高時間解析度之氣象與氣膠觀測，觀測結果發現：種雲焰劑之施放導致水氣競爭效應以及凝結過程的產生，並且於施放地域生成更多的雨滴。在數值模擬方面，吾人利用WRF模擬2020年10月21-22日之種雲實驗個案，以自行開發之雲微物理參數化方案(WDM6-NCU)進行雲微物理模擬，WDM6-NCU雲微物理參數化方案可利用43個細格描述雲凝結核之粒徑分布，可給定觀測所得之種雲焰劑粒徑分布，更真實及完整地計算雲凝結核之活化過程，模式模擬結果顯示：就人工種雲效率來說，雲內種雲相較於在雲底種雲可以增加更多降水，且增加種雲播撒面積與種雲粒子濃度可以增加數倍的降水生成；對於雲微物理過程，雨滴之碰併過程的增強為造就降水增加之主要原因，且吸濕性粒子大於0.4 μm有助於引發後續一連串成雲降雨過程。整體而言，本研究開發出一套本土化的人工種雲氣象模式，成功地解釋暖雲種雲至降雨之過程，搭配觀測資料之分析與驗證，可做為未來人工種雲實務作業之重要依據。 ;Global warming causes droughts to increase in intensity and frequency. In 2021, Taiwan faced the most serious drought in the past hundred years, prompting Taiwan government to seek ways to deal with the problems of water scarcity. Hygroscopic cloud seeding seems to be a possible solution to create more water resources. The goals of this study attempt to investigate the suitable environmental conditions for hygroscopic cloud seeding and its impacts on cloud microphysics by both observation and model simulation. Furthermore, based on a case study of hygroscopic cloud seeding in northern Taiwan catchment, an effective and scientific strategy of hygroscopic cloud seeding seeks to be proposed. During 2019-2021, four Dongyan mountain cloud-seeding experiments were executed with meteorological and aerosol observation, and the results indicate that: the seeding agents can strengthen the competition effect and the condensation process. Moreover, the concentration of raindrops increases after doing cloud seeding. For model simulation, the WRF model with a hybrid cloud-seeding microphysics scheme, WDM6-NCU, which is able to describe seeded CCNs size distribution by 43 bins and precisely evaluate the activation of seeded CCNs, is used to simulate the case on 21-22 October 2020 with a series of sensitivity tests on cloud seeding. Results of model simulation show that: more precipitation is developed in the scenarios seeding at the in-cloud region, and seeding in a bigger domain and higher hygroscopic particles concentration are able to increase several folds of rainfall. Regarding the microphysics processes, the main reason causes the enhancement of precipitation is the strengthening of the accretion process of raindrops, and those hygroscopic particles bigger than 0.4 μm are the main factor contributing to cloud-seeding effects. In conclusion, this study develops a hybrid cloud-seeding microphysics scheme, which successfully explains the process from launching cloud seeding to developing rainfall and matches the features of observation data. In addition, the results of this study can be used as a guidance for the future operation of cloud seeding in Taiwan.
顯示於類別:	[大氣物理研究所 ] 博碩士論文

文件中的檔案:

檔案	描述	大小	格式	瀏覽次數
index.html		0Kb	HTML	71	檢視/開啟

在NCUIR中所有的資料項目都受到原著作權保護.

社群 sharing

資料載入中.....