水稻區近地面邊界層動量、熱量及水汽量之垂直通量分析

The Study of Vertical Flux of Momentum, Heat and Mass in the Surface Boundary Layer

楊之遠(Chea-Yuan Young) ； 柳中明(Chung-Ming Liu)

《大氣科學》 16卷4期 (1988/12) Pp. 391-408

摘要

本文應用中央氣象局嘉義氣象測站之微氣象自動觀測系統，在水稻集團上方所測定之近地面溫度、濕度、風速、輻射量等資料，以分析水稻葉冠集團與近地面（4公尺以下）大氣間動量、熱量與水汽量在74年4月～6月間之垂直輸送情形。所得結果顯示，日間水稻集團上方風場、溫度場與濕度場變化極大。因此自水稻集團向上傳送之熱量與水汽量在12-13時間達最大值，而自大氣向下傳送之動量在17-19時達高值。另外4-6月間，時平均風速逐漸減弱，風向趨穩定，是以動量垂直輸送在水稻分孽期（4月2日－20日）為相當重要，但至成熟期（5，6月）由於氣溫與相對濕度增加，因此熱量與水汽量自水稻向上輸送，為相當重要之水稻與大氣相互作用機制。此外，本文尚提供地表粗糙程度Zo、摩擦速度U*、熱量通量、水汽量通量、日射量、淨輻射量等之相關方程式，希望有助於氣象模式中對地表邊界條件之決定。

關鍵字

近地面邊界層 ； 水稻葉冠與大氣相互作用 ； 動量 ； 質量 ； 熱量垂直輸送

並列摘要

The entities (momentum, heat and water vapor) transport flux between rice canopy and atmosphere were estimated by aerodynamic and Bowne's ratio method, i.e., in the viewpoint of micrometeorology. The results indicated the maximum downword momentum flux to the rice canopy were occurred in the afternoon, due to the higher windspeed. The maximum heat and water vapor transport flux were occurred at noon, because the highest solar radiation and net radiation, which caused the greatest temperature and humidity gradient between rice canopy and atmosphere. The water vapor flux can be used as an index of the evapotranspiration of rice community.The daily variation tendency of heat and water vapor flux estimated by both aerodynamic and Bowen's ratio methods were much similar. So the authors suggested that the application of the micrometeorological methods to estimate the water comsumption of crop community in the field, should be an easier and effective way, it can be observed continuously in a nature condition, thus to understand the variation of evapotranspiration of daily and whole growth period of crop community.

並列關鍵字

Surface Boundary Layer ； Interaction between Atmospheric and Rice Canopy