| 摘要: | 臺灣西臨歐亞大陸，東靠太平洋，太平洋高壓與大陸高壓的強弱大致主宰了臺灣四季的天氣變化。此外，臺灣為一個地形崎嶇的海島型國家，過去眾多研究中顯示，部分地區的污染物濃度分佈、降水時間強度會受到海陸風的影響。海陸風也會和更大尺度的環境風場偶合，影響降水時空分布。海陸風的過去研究多以地面測站或是模式模擬，較少針對垂直的大氣結構探討。故本計畫藉由近年新興之無人機大氣觀測技術搭配光達的觀測，提供相較於以往探空氣球有較高的時間與垂直空間解析度。具有豐富 多元的儀器酬載能力的優勢，並加上地面觀測之觀測結果，南部地區典型海陸風垂直結構日夜變化及三維局地環流特徵，期望做未來天氣守視的重點及氣象預報之參考。 在具體工作規劃上，本計畫提出 由地面觀測資料、再分析場與模式等資料初步建構南部地區海陸風之特徵，並作為弱綜觀密集觀測策略擬定之依據；第一年 前期 密集觀測期間，選定台南地區自近海、平原至近山區三測點，進行無人機同步及日夜連續觀測，建構時序性海陸風剖面，並透過整合資料分析，描述弱綜觀天氣條件下，局地環流與海陸風特徵，及對於空氣品質的影響。第二年的工作(本期)將延續第一年的成果，持續精進改良觀測策略，並執行一次密集觀測實驗，特別針對海陸風所造成的降水事件進行觀測，根據兩年的成果，本計畫希望統整提出，臺灣南部弱綜觀海陸風的特徵與對於空氣品質與降雨的影響。 ;Many researches showed that the distribution of air pollution and the timing, strength of precipitation would be affected by land-sea breeze in Taiwan. Land-sea breeze would affect the distribution of precipitation coupling with large-scale environmental wind. Most of studies of land-sea breeze were based on the results from surface observation or model simulation, on the other hand, the observation evidences of vertical structure are limited. Therefore, to resolve the vertical structure of atmosphere by using Unmanned Aircraft System (UAS) might be a new direction. Advantages of UAS includes a higher payload and higher spatial-temporal resolution as compared with traditional sounding balloons. The proposed project will use UAS to observe atmospheric profile and study the typical diurnal change of land-sea breeze under weak synoptic weather condition in southern Taiwan. The new strategy of UAV (unmanned aerial vehicle) observation is hoping to be a consultation of weather monitoring and weather forecast in the future. For the detailed proposal, first of all, our team are going to analyze historical observation data, reanalysis data, and modeling data to examine the features of land-sea breeze over southern Taiwan, and make a better observing strategies according to the features. For the first year (2021 year), three spots synchronous day-night UAV observations will be carried over Tainan during intensive observing periods. By the integration analysis of UAV, sounding balloon, and ground station observation data, we can get the whole picture of the land-sea breeze over southern Taiwan under weak-synoptic weather condition. For the second year (2022 year), our team will improve observing strategies continuously, and perform another IOP in 2022 based on the experience in 2021. In addition, we will look into the interactions between land-sea breeze and rainfall. Finally, we would like to characterize the features of the land-sea breeze under weak-synoptic weather condition, and to summarize its impacts on regional air quality and precipitation. |
