利用GRACE时变位模型研究南极冰盖质量变化
Investigation on the Mass Variations of Ice Sheet in Antarctic with GRACE Time-variable Gravity Models
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摘要: 对CNES/GRGS和UTCSR GRACE Level-2产品重力位模型的J2项时间序列进行了主成分分析和比较,结果表明,CNES/GRGSJ2项具有更好的季节性变化特征,利用CNES/GRGS GRACE Level-2产品推求了南极地区冰盖质量变化速率,并对西南极和东南极冰盖质量变化进行了主成分分析,获取了其周年项振幅和相位。分析表明,南极地区冰盖质量变化呈现出明显的地区不平衡性和季节性变化特征,西南极冰盖存在有较强的减少趋势,利用主成分重构和调谐分析方法获得的西南极和东南极冰盖质量变化的周年项振幅分别为2.4 cm和1.3 cm等效冰高。Abstract: In this paper,Empirical Orthogonal Functions(EOF) is used to analyze the time series of GRACE J2 inferred from CNES/GRGS and UTCSR to see the characteristics and the differences.The results show that the seasonal variation of J2 time series from CNES/GRGS is clearer than that from UTCSR.With CNES/GRGS GRACE Level-2 products,the mass rates of ice sheet in Antarctic are then computed.And,the mass variations in West Antarctic and East Antarctic are analyzed using EOF,whose annual amplitudes are also derived.The analysis indicates that the mass variations of ice sheet in Antarctic show regional seasonal change,the mass of ice sheet in West Antarctic is decreasing clearly.The annual amplitudes after EOF reconstruction and harmonic analysis in West Antarctic and East Antarctic are 2.4 cm and 1.3 cm respectively.
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