| 摘要: | 本文旨在利用自動雲凝結核計數器（DMT continuous flow streamwise thermal gradient cloud condensation nuclei counter, CCN counter）在鹿林山（23.47° N，120.87° E，2,862 m）、陽明山國家公園竹子山區（25.11° N，121.31° E，1,103 m）和富貴角（25.15° N，121.33° E，229 m）進行雲凝結核之觀測研究，以探討不同地域的氣膠活化成為雲凝結核時之微物理特性。研究分為三個階段進行觀測：鹿林山觀測時間為2008年10月30日到11月1日，以及2008年12月9日到12月12日。觀測期間發現雲凝結核有明顯的日夜變化，其濃度主要受白天谷風的影響。其次，竹子山在2009年2月14-19日間進行觀測，結果發現不同空氣源會影響雲凝結核成為雲滴時的濃度和粒徑。此外，在雲霧中進行雲凝結核的觀測，顯示濃度會明顯變少，說明雲霧對雲凝結核的去除作用。最後在2009年3月26-31日進行富貴角的觀測，發現降雨會使雲凝結核的濃度減少。本文也根據雲凝結核的指數定律關係式NCCN=CSk得到這些地域的相關參數。研究結果發現鹿林山觀測期間的空氣類型比較接近大陸型氣團，雲凝結核微物理參數C和k約為110 cm-3與0.72，而竹子山與富貴角觀測期間之空氣類型則較接近海洋型氣團，其C和k值分別為1,116 cm-3與0.37（竹子山），以及1,015 cm-3與0.36（富貴角）。 The purpose of this study is to characterize the cloud condensation nuclei (CCN) measured at Lulin Atmospheric Background Station (LABS, 23.47° N, 120.87° E, 2862 m MSL), Mt. Bamboo (25.11° N, 121.31° E, 1103 m MSL), and Fugueijiao (25.15°N, 121.33° E, 229 m MSL) using a DMT (Droplet Measurement Technologies) continuous flow streamwise thermal gradient cloud condensation nuclei (CCN) counter. The study conducted the observations at three sites. First of all, the measurements of CCN were performed at LABS from October 30 to November 1, 2008 and during December 9-12, 2008. As a result, an obvious diurnal variation of CCN concentrations was observed, which was influenced by valley breeze in the daytime at LABS. Second, the measurements of CCN were performed at Mt. Bamboo during February 14-19, 2009. It showed that the air mass from different sources can affect the concentration and particle size of cloud droplets which are formed by CCN. Meanwhile, CCN concentrations apparently decreased during the cloud event. The last CCN observation was conducted at Fugueijiao during March 26-31, 2009. Consequently, it shows that there is an obviously scavenging effect on CCN particles when precipitation occurred. Furthermore, according to the expression NCCN = CS k, the CCN spectra can be described. The fitted spectral parameters C (about 100) and k (about 0.70) for LABS case can be classified to be continental type. However, the CCN spectra of Mt. Bamboo and Fugueijiao were shown to be maritime origin. The parameters C (about 1000) and k (about 0.40) for both cases were similar. |
