Ice mass change in Greenland and Antarctica between 1993 and 2013 from satellite gravity measurements

摘要

We construct long-term time series of Greenland and Antarctic ice\udsheet mass change from satellite gravity measurements. A statistical reconstruction\udapproach is developed based on a Principal Component Analysis to combine\udhigh-resolution spatial modes from the Gravity Recovery and Climate Experiment\ud(GRACE) mission with the gravity information from conventional satellite track-ing data. Uncertainties of this reconstruction are rigorously assessed; they include\udtemporal limitations for short GRACE measurements, spatial limitations for the\udlow-resolution conventional tracking data measurements, and limitations of the estimated\udstatistical relationships between low and high degree potential coe�cients\udre\udected in the PCA modes. Trends of mass variations in Greenland and Antarctica\udare assessed against a number of previous studies. The resulting time series\udfor Greenland show a higher rate of mass loss than other methods before 2000,\udwhile the Antarctic ice sheet appears heavily in\uduenced by interannual variations.