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Oceans Melting Greenland (OMG)

OMG logoOceans Melting Greenland (OMG) is a 5-year (2015-2020) NASA Earth Venture Suborbital (EVS-2) mission that aims to improve estimates of sea level rise by addressing the question: To what extent are the oceans melting Greenland’s ice from below? OMG will observe changing water temperatures on the continental shelf surrounding Greenland, and how marine glaciers react to the presence of warm, salty Atlantic Water. The complicated geometry of the sea floor steers currents on the shelf and often determines whether Atlantic Water can reach into the long narrow fjords and interact with the coastal glaciers. Because knowledge of these pathways is a critical component of modeling the interaction between the oceans and ice sheet, OMG will facilitate improved measurements of the shape and depth of the sea floor in key regions.

OMG will use NASA’s G-III to fly the Glacier and Ice Surface Topography Interferometer (GLISTIN-A) in order to generate high resolution, high precision elevation measurements of Greenland’s coastal glaciers during the spring. Annual surveys by GLISTIN-A will measure glacier thinning and retreat over the preceding season. A second aircraft campaign will occur each summer to deploy 250 expendable temperature and salinity probes along the continental shelf to measure the volume and extent of warm, salty Atlantic Water. These data, along with fundamental new and critical observations of airborne marine gravity and ship-based observations of the sea floor geometry will provide a revolutionary dataset for understanding ocean/ice interactions and lead to improved estimates of global sea level rise.

Instruments
  • AXCTD - Airborne eXpendable Conductivity Temperature Depth is similar to the shipboard CTD, but dropped from a plane and not retrieved. It sends a radio signal with the CTD measurements as the probes fall through the water column.
  • CTD - Conductivity, Temperature and Depth is a shipboard instrument. It measures water conductivity, which is translated into salinity, temperature and depth. These measurements are then used to calculate density.
  • GLISTIN-A - Glacier and Ice Surface Topography Interferometer is an airborne single pass interferometric Ka-band radar. It is provides digital elevation maps of the glaciers and surrounding areas within the last 8 km or so of their termini.
  • MBES - Multibeam Echo Sounder System measures bathymetry (the shape and depth of the sea floor). It uses a sonar that produces an angular swath of beams to the port and starboard side in a single ping to effectively map a corridor with a width approximately 3-4 times the water depth.
  • SBES - Singlebeam Echo Sounder System measures bathymetry in additional areas. It provides only a single measurement of water depth, directly beneath the ship.
  • AIRGrav - Airborne Inertially Referenced Gravimeter measures the pull of gravity caused by the land or water and sea floor below the aircraft. This is used to calculate the shape and depth of the sea floor.
Data Products (Coming Soon)
  • AXCTD ocean water properties
  • CTD ocean water properties
  • GLISTIN-A glacial heights
  • MBES bathymetry
  • SBES bathymetry
  • AIRGrav bathymetry