隨著太空測地技術的成熟，加上GRACE衛星任務成功的科學進展及新結果，地球重力場的時變在全球變遷的研究中，已成為一項新的遙測工具。藉由研究地球重力場的時變，我們對於整個地球系統中地球物理或是氣候變化所造成的質量轉變，可以得到重要且前所未有的資訊。在本計畫中，我們打算藉由地球重力場時變的觀察，研究四個特訂的大規模現象。在研究當中，通常會再與其他獨立的資料類型一起做比對，包括衛星雷射測距、地球自轉測量、衛星海洋測高、以及全球環流模式(GCM)的產品。(1) ENSO (El Nino/Southern Oscillation)海平面變化：利用複變經驗正交函數 (CEOF)，帶入GRACE地球重力場的時變及相關的海面測高資料，分析研究ENSO的動力及演化過程之熱脹與質量的變化；(2) 地震對地球重力場的影響:研究地震的運動及動力模式，以了解地震促使地球逐漸變圓的機制；(3) 利用GRACE數據及GCM的產品研究陸地水文的質量平衡；(4) 利用地球自轉變化數據及GCM的產品，以研究地球各部件的角動量轉變中的重要動力參數。此計畫性質屬高度跨領域工作。除了增強上述四領域的知識以外，本計畫希望達成在台灣建立此項領域的研究力量，以了解、模擬、以致預測全球及地區性的地球物理與氣候變遷，這是對於人類永續生存非常重要的。由於此項計畫需要深入的學習並訓練研究團隊以及開發新的軟體計算方法，我們提出為期三年的計畫，也預期這項研究能持續並超越三年時期，提出更廣更深並使用更先進數據的研究工作。 ; With the maturity of the space geodetic technique and the successful scientific developments and findings of the GRACE mission (launched in 2002), time-variable gravity (TVG) has become a new tool for remote sensing of the Earth’s global changes, yielding important and unprecedented information about mass transport associated with many geophysical and climatic variations in the atmosphere-hydrosphere-cryosphere-solid Earth system. In this proposal we intend to investigate the following specific large-scale phenomena based on TVG observations and in conjunction with other independent data types, including satellite laser ranging, Earth rotation measurements, satellite ocean altimetry, as well as global circulation models (GCM) of atmosphere, ocean and hydrology: (1) ENSO (El Nino/Southern Oscillation) sea level variations using the empirical-orthogonal-function technique on GRACE TVG and corresponding ocean altimetry data to separate and study the steric and mass-induced variations in the dynamics and evolution of ENSO; (2) Earthquake effects on TVG: to study the kinematic and dynamic mechanisms by which earthquakes tend to make the Earth rounder (i.e. decreasing J2); (3) Land hydrological water mass balance using GRACE data and GCM outputs; (4) Inference of Earth dynamic parameters relating to angular momentum transports using Earth rotation variation data and GCM outputs. The proposed investigation is highly interdisciplinary in nature. In addition to the advancement of knowledge about the above specific areas, the proposal has the overall goal of establishing TVG research capability in Taiwan, in terms of understanding, modeling, and predicting the global/regional geophysical and climatic changes, which are of crucial importance to the human livelihood and sustainability. On account of the degree of elaboration of these studies and the fact that they require considerable training of investigators and development of computing methodologies, we propose a time period of 3 years, aiming to be able to continue the studies beyond the 3 years with enlarged and refined scope and more advanced data. ; 研究期間 9708 ~ 9807
