全球變遷對西北太平洋臺灣海域海洋生物地球化學與生態系統影響之長期觀測與研究(I)-子計畫：全球變遷因子對東海及西北太平洋黑潮海域環流與渦流變動之影響：環流數值模式
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Date
2013-07-31
Authors
吳朝榮
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行政院國家科學委員會
Abstract
近年來，東海環流之研究已經有很顯著的進展，也勾勒出東海的洋流系統與其 季節性變化。最近有許多以短時間尺度擾動為主的研究，然而少有研究是針對 長時間尺度的氣候變遷因子，如聖婴現象和太平洋年代際震盪等，因而這些因 素對於環流系統的影響還不甚明瞭。東海的環流系統是生地化領域用來探索東 海的重要依據之一，如研究區域湧昇對基礎生產力的影響等，這些都必須考量 環流系統如何受氣候影響而改變，所以明瞭環流系統在不同氣候變遷因子影響 下的變動是相當重要且迫切的議題。東海環流系統主要受兩項因素主導，其一 是作用風場，季節性風向的轉換與強弱變動是季節性海流變化的成因，其二是 上游黑潮傳輸量的變化。要釐清複雜的東海環流變化，需要連續的時空序列資 料來做分析。雖然實地觀測是取得海洋環境參數最佳的方法，然而人力與設備 的有限、無法兼顧長時間與廣範圍的觀測。而衛星遙測最大的優點在於能夠大 範圍的監測整個海域，比起實地觀測更有助於研究其連續性變化。數值模式的 優點在於時間序列上是完整連續的，且空間上能完整得到不同深度的物理量。 故本研究主要以數值模擬來探討在不同氣候變遷因素影響下，東海環流及黑潮 的變異與歸因，並輔以衛星遙測與實測資料來做比對。
Recent measurements have shed some light on the circulation of the East China Sea. Several mean currents in the region and their seasonality are well documented in the literature. Even more recently, waves and tides are considered to be essential and included in the dynamical interpretation of the East China Sea study. On the other hand, effects of long-term global changes on the East China Sea and Kuroshio are seldom explored at the present time. As climate changes in this century, the current distribution under varied climatic conditions will be rearranged on the globe. The modulation of the East China Sea circulation under the climate changes, such as El Nino/La Nina-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO), deserves to be further studied. Understanding the East China Sea circulation (and the Kuroshio) is essential to ocean biogeochemistry and Ecosystems in the region. Seasonal monsoon and the fluctuation of the upstream Kuroshio should play critical roles on the multiple-scale variabilities of the East China Sea circulation. In addition to in-situ measurements, satellite remote sensing data and numerical modeling efforts are adopted to analyze the circulation and multiple-scale variabilities of the East China Sea and Kuroshio in the present study. We are planning to improve the previous model by refining bathymetry and forcing with a higher horizontal resolution, bringing the model skill to a level capable of coping with in-situ observations. The improved East China Sea model is expected to resolve temporal and spatial scales of interest. We will use the simulation results to discuss the seasonal, inter-annual and inter-decadal variations in the region. With finer model grids, refined topography representation and improved temporal resolution in atmospheric forcing, this work will offer reasonable simulations and interpretations on the variability in the East China Sea and Kuroshio.
Recent measurements have shed some light on the circulation of the East China Sea. Several mean currents in the region and their seasonality are well documented in the literature. Even more recently, waves and tides are considered to be essential and included in the dynamical interpretation of the East China Sea study. On the other hand, effects of long-term global changes on the East China Sea and Kuroshio are seldom explored at the present time. As climate changes in this century, the current distribution under varied climatic conditions will be rearranged on the globe. The modulation of the East China Sea circulation under the climate changes, such as El Nino/La Nina-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO), deserves to be further studied. Understanding the East China Sea circulation (and the Kuroshio) is essential to ocean biogeochemistry and Ecosystems in the region. Seasonal monsoon and the fluctuation of the upstream Kuroshio should play critical roles on the multiple-scale variabilities of the East China Sea circulation. In addition to in-situ measurements, satellite remote sensing data and numerical modeling efforts are adopted to analyze the circulation and multiple-scale variabilities of the East China Sea and Kuroshio in the present study. We are planning to improve the previous model by refining bathymetry and forcing with a higher horizontal resolution, bringing the model skill to a level capable of coping with in-situ observations. The improved East China Sea model is expected to resolve temporal and spatial scales of interest. We will use the simulation results to discuss the seasonal, inter-annual and inter-decadal variations in the region. With finer model grids, refined topography representation and improved temporal resolution in atmospheric forcing, this work will offer reasonable simulations and interpretations on the variability in the East China Sea and Kuroshio.