有鑑於降雨對台灣的重要性,我們將研究以下三項課題: (1)全球暖化對氣候帶變遷的影響本研究將使用美國NOAA NCEP 和歐洲中期天氣預報中心(ECMWF)的再分析資料來研究東亞和太平洋過去50 年氣候變化的現象。預計使用各種分析的工具,例如EOF 和SVD,來研究氣候的變化和趨勢。台灣區域氣候變化的特徵 (如溫度、降水) 與東亞和太平洋地區大規模的氣候變化的相關性將是本研究的重點。 (2) 地形對對流和降雨的影響未來將使用ECMWF 的YOTC 25-km 解析度以及NCEP GFS 經過WRF 初始化後產生的5-km 高解析度的資料來研究地形對對流和降雨的影響。並將對莫拉克颱風侵台期間(7-9 August 2009)以及 SoWMEX/TIMREX 實驗期間(2008 年5 - 6 月)西南氣流引發的強降雨事件進行個案的探討。 (3) 改進WRF 成為適合台灣區域特性的模式除了已將我們自己發展的輻射模式植入WRF 外,我們將持續地改善WRF 模式。我們將針對台灣和周圍的特殊區域條件來更新邊界層和雲對流的機制,也會嘗試將WRF 和區域海洋模式結合,以改進海氣熱量交換的計算。這份計畫將從2010 年1 月1 日至2012 年12 月31 日持續3 年。我們未來將積極與國內外的科學家共同合作研究,包括和美國NASA GSFC 的陶為國博士研究小組及美國威斯康辛大學王寶貫教授合作研究雲微物理和降雨機制、和國立中央大學教授合作研究改進WRF 模式及增進瞭解全球暖化對臺灣氣候變化的衝擊、和國立台灣大學教授合作研究夏季風季風的變異。改進後的WRF 模式將有助於晚春生物燃燒對台灣春雨及初夏南中國海上的西南季風的研究 --- 這也是國際7-Sea 計畫的任務之一;中央大學林能暉教授是該計劃主持人。 In view of the importance of rainfall prediction in Taiwan, we propose to undertake the following three research tasks: (1) Impact of global warming on climatic regime shift The NCEP and ECMWF global reanalysis data will be used to study spatial patterns of climate change in East Asia and the Pacific during the past 50 years. Various analysis tools, such as EOF and SVD, will be used to investigate the climatic pattern change and trend. Characteristics of local climate change in Taiwan, such as temperature and precipitation, will be related to the large-scale climatic pattern change, or climatic regime shift, in East Asia and Pacific regions. (2) Impact of topography on convection and precipitation The ECMWF YOTC 25-km resolution analysis and the high spatial resolution (5-km) data derived from the NCEP GFS data with application of WRF assimilation / initialization schemes will be used to study the impact of topography on convection and precipitation. Case studies will be carried out for Morakot typhoon (2009) and severe rainfall events associated with the summer monsoon southwesterly flow during the SoWMEX/TIMREX field experiment (May-Jun 2008). (3) Improvement of WRF model suitable for Taiwan regional conditions We will continue to improve the WRF model by replacing schemes of boundary layer and cloud convections specifically suitable for regional conditions over Taiwan and its vicinity. We will also couple the WRF with a regional ocean model for improvement in air-sea heat exchanges. The proposal will cover a three-year period from 1 January 2010 to 31 December 2012. We will engage in domestic and international collaborations with scientists from NASA Goddard Space Flight Center on cloud modeling (Dr. Tao’s research group), from the University of Wisconsin (Prof. P.-K. Wang) on cloud microphysical and dynamical processes, from National Central University on WRF model improvement and on local climate change in relation to global warming, and from National Taiwan University on summer monsoon regime shift. The improved WRF model will be used to support the study on the impact of biomass burning on late spring - early summer southwesterly monsoon flow in South China Sea, which is one of the tasks of the 7-Sea project with Prof. N.-H. Lin of National Central University as the project Principle Investigator. 研究期間:9901 ~ 9912