本文說明利用一種結合Vaisala RS80-15G全球定位衛星無線電導航探空儀的定體積氣球探空載具（CPB），透過CPB所提供之精緯度和高度資料，解析低層大氣氣流軌跡線之方法與觀測實驗結果。本研究在2002年冬天到2003年春天於南臺灣地區空氣汙染事件日期間，共進行26次有效之CPB施放，其中追蹝時間超過2小時的樣本計有15份，追蹤時間超過6小時之樣本計有6份，單一個案最長追蹤時間和最遠距離分別是8.4小時和81公里。在冬季高壓迴流天氣類型之追蹤個案中，CPB軌跡追蹤觀測顯示南高屏地區1400∼1900公尺逆溫層以上之氣流場，可以是西北或是東南向，有時此兩種反向氣流場在南高屏地區形成鞍形場而造成短暫靜風之現象，但是逆溫層以下之盛行風則是以西北風為主。在春季鋒面徘徊天氣類型之個案中，南高屏平原地區的低層風場逐日變化相當劇烈，亦曾觀測到西風氣流行經山地引發山岳波之現象。在春季暖濕氣流天氣類型之個案中，可見行經高雄林園石化工業區之低層氣流循高屏溪河道北上，飄移至高屏溪中游之美濃內陸地區，或往東南沿岸地區飄移，並進入中央山脈南端山區等情況，此觀測結果與先前利用地面污染物觀測網資料推估氣流傳輸擴散之研究結論一致。比較CPB氣流追蹤觀測資料和MMS中尺度天氣模式軌跡資料，發現場CPB觀測結果比數值模式產品能更合理反應地形效應。

　　　　　This study describes the diagnosis of low-level wind field with the special sounding platform which is the combination of Vaisala RS80-15G GPS-sonde and the special constant volume balloon （called CPB）. During the high-polluted events in Southern Taiwan from 2002 wintertime to.2003 springtime, the geographic position and altitude of CPB were treated as the trajectory of the low-level wind flow. In the 26 tracking cases, 15 cases which had been tracked time over 2 hours were obtained and six of them had over 6-hour flights.. The longest durance and the maximum distance of CPB observations were 8.4 hours and 76km. CPB trajectories in the cold surge case showed that airflow above the inversion layer （1400∼1900m） may change the direction from northwest to southeast. Calm weather can happen temporarily caused by the anti-directional convergent wind, but the northeastern wind below the inversion layer were always significant. In the case of stationary frontal system, the airflow direction changed a lot day by day, and one mountain wave-like trajectory was recorded when westerly wind forced CPB over the mountain region. CPB trajectories during southern warm air flow in springtime showed that polluted air from Kao-hsiung petroleum plants might transport into Meinung mountain region. It might transport along the southeastern beach region and arrived to the end of Central Mountain, too. The previous studies according to ground air-sampling measurements expected the same trajectories CPB had in this study. The forward trajectory produced from MM5 meso-scalel model was used to compare with CPI3 trajectories measurements. We found CPB trajectories had reasonable features to response the terrain effect than model products.