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Images from Grace Mission
12.20.05
 
Movie: Gravity Field Variations Observed by Grace
This is an animation of the variations in the Earth's gravity field observed by GRACE over the period 2002-2005. The variations are expressed as the amount of water in each location at the Earth's surface required to create the gravity change GRACE observe, because the main source of these variations is redistribution of water due to land surface hydrological processes like precipitation and river runoff, polar ice mass changes, and oceanography.

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Earthquake Signal Visible in GRACE Data
This figure shows the effect of the December 2004 great Sumatra earthquake on the Earth's gravity field as observed by GRACE. The signal is expressed in terms of the relative acceleration of the two GRACE satellites, in this case a few nanometers per second squared, or about 1 billionth of the acceleration we experience everyday at the Earth's surface.
This figure shows the effect of the December 2004 great Sumatra earthquake.

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Antarctic Circumpolar Current
The Antarctic Circumpolar Current (ACC) is the strongest current system in the world oceans, the one that links the Atlantic, Indian and Pacific basins. GRACE is the first satellite system that lets us see 'through' to the seafloor, to measure monthly changes in the combined weight of ocean plus atmosphere. This translates into the pressure gradients associated with mass transport.
The Antarctic Circumpolar Current (ACC) is the strongest current system in the world oceans.

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Antarctic Circumpolar Current, Vertically Averaged TRANSPORT
Variability in the top-to-bottom (barotropic) transport of the ACC has been notoriously difficult to obtain. For the first time the GRACE satellites offer a continuous view of this current and its variability, all around the Antarctic continent, for almost 3 years. This first study shows the seasonal variability of the current and unambiguously relates it to eastward wind stress. (Wind from the QUIKSCAT satellite, averaged over latitudes 40 to 65S, and al longitudes). Longer time series will undoubtedly show us interannual changes, and link them to low latitude climate variability.
For the first time the GRACE satellites offer a continuous view of this current and its variability.

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GRACE Measurements Show Mass Loss in Greenland
This figure shows the ice mass loss in Greenland as observed by GRACE over the period 2002-2005 measured in cubic kilometers per year. The ice mass loss observed by GRACE contributes about 0.4 mm/yr to global sea level rise. GRACE is continuing to observe Greenland and other polar ice caps to better understand these phenomena.
This figure shows the ice mass loss in Greenland.

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