摘要:由於水體與陸地在許多物理性質上具有高度的差異性(如熱容、粗糙尺度、或反照率),因此海陸交界之處的大氣邊界層具有顯著的複雜性,也因此對於許多大氣與地表的交互作用會產生明顯的影響。
本研究主要的目的是針對海陸交界之處的大氣邊界層與近地層進行長期觀測與數值模擬。主要的觀測和模擬對象是針對地表與大氣之間的交互作用,包括動量、能量與質量(如水蒸氣、二氧化碳、氣膠、臭氧或其他化學物質)進行長期觀測,並建立相關的數值模擬模式。為了達成上述的目的,本研究選定台北縣淡水鎮中央廣播電台淡水分台的微波天線接收塔作為研究之場址。計畫將把相關微氣象與環境監測儀器架設在現場的100公尺高的微波塔上,藉由量測垂直方向上相關氣象與環境參數的分佈,瞭解在當地這種海陸交界處的微氣象特徵,並進一步地量化估算相關參數(能量、動量與質量)的在大氣與地表之間的交互作用。
相關的工作主要包括:
1. 在海陸交界處,100公尺微波塔上,建立長期且連續性的觀測系統,並進一步量測在特殊的氣象或環境條件下(如:梅雨季節、颱風季節、沙塵暴事件等),相關的近地層微氣象特徵與地表-大氣交互作用的特性。
2. 除現地長期量測之外,也預計將以探空氣球資料蒐集上空一公里範圍之內的資料,藉以補足地面觀測之不足。
3. 建立相關的一維多層模式,模擬地表與大氣之間相關的動量、能量以及質量之交換,並藉由現地資料的量測,獲取中尺度大氣模式所需的地面參數,並進一步地進行相關測試。
4. 針對一些特殊的大氣或環境事件(如沙塵暴、海鹽擴散、臭氧污染事件等),進行為氣象尺度與中尺度大氣模式之探討。
5. 以相關資料加入「台灣通量觀測塔網資料庫」(目前正在執行中,由中興大學莊秉潔教授擔任計畫主持人,本人與其他學者擔任共同主持人,國科會計畫編號:97-2745-M-005-001)
Abstract: The atmospheric boundary-layer close to the land-sea interface is known to be a very complex environment because of the difference in physical characteristics between the land and water, such as heat capacity, surface albedo, roughness length, and etc. The highly inhomogeneity in such region make it more complicate to quantify the boundary-layer dynamics, momentum and mass fluxes, and the energy budgets in the vicinity.
In this study, in order to systematically obtain the long-term observations and investigate the relevant research questions involved the characteristics of the surface-atmosphere interactions, including the momentum components, scalar exchanges and energy budget, at the land-sea interface within the atmospheric boundary-layer scale, a long-term micrometeorological and environmental monitoring system is proposed to be established on a 100-meter-high microwave antenna tower in “Tamsui Branch of Radio Taiwan International” in Tamsui Town of Taipei County.
The major purpose of this project is to characterize and further quantify the surface-atmosphere interaction and the boundary-layer (or surface-layer) dynamics close to the land-sea interface. The major objectives of this project include:
1. Establish an in-field observation system to measurement the micrometeorological and environmental data, including vertical profiles of the momentum components, air temperature, relative humidity, carbon dioxide concentrations, energy budget and other airborne chemicals (aerosols, ozone, and sea salts) to further investigate the surface-atmosphere interaction of these quantities at the land-sea interface.
2. Conduct the atmospheric sounding experiments using radiosonde devices under different atmospheric stability conditions over different diurnal and seasonal cycles. The major purpose of this proposed atmospheric sounding experiment is to collect the data up to the atmospheric boundary-layer (~km). The radiosonde data collected from the experiments could be used to provide the necessary information to upscale the data from the 100-m antenna tower data, and could offer the general estimates of the flux over a larger spatial scale.
3. Develop numerical models involving the boundary-layer meteorology and surface processes to quantify dynamics and evolutions of these quantities. In addition, few other meso-scale atmospheric models, such as MM5 and WRF, will be used to test the parameterizations obtained from the observations in the land-surface modules in each model.
4. Explorer several advanced research topics related to the land-use characteristics and their impacts on the near-surface atmospheric dynamics in different situations in such region.
5. For the long-term basis, the results from this project will be used to establish the Taiwan micrometeorological flux network