Airborne Topographic Mapper Calibration Procedures and Accuracy Assessment

Description of NASA Airborn Topographic Mapper (ATM) lidar calibration procedures including analysis of the accuracy and consistancy of various ATM instrument parameters and the resulting influence on topographic elevation measurements. The ATM elevations measurements from a nominal operating altitude 500 to 750 m above the ice surface was found to be: Horizontal Accuracy 74 cm, Horizontal Precision 14 cm, Vertical Accuracy 6.6 cm, Vertical Precision 3 cm

Bathymetric control of tidewater glacier mass loss in northwest Greenland

It has been suggested that fjord geometry could be an important contributor to the observed mass loss variability in Greenland by modulating the flow of warm water to marine-terminating glaciers. New gravity-derived bathymetry of Greenlandic fjords confirms the link between the grounding line depth and rates of glacier mass loss, a relationship previously predicted only in ice models. We focus on two neighboring glaciers to minimize differences in external forcing and therefore isolate the role of the fjord bathymetry. Tracy Glacier has a deeper grounding line and has been retreating since 1892 with a contemporary mass budget of −1.63 Gt a⁻¹ . Heilprin Glacier has a shallower grounding line depth, a stable ice terminus, and a mass budget of only −0.53 Gt a⁻¹ . Because of its deeper grounding line, Tracy has more ice in contact with warm subsurface water, leaving it more vulnerable to changes in ocean forcing and therefore mass loss

Greenland: Pan to West Coast Area of Interest

This animation shows the ice concentration in Greenland. The ice has decreased significantly (~50 cm-year) along the coast and increased slightly in the center (+2 cm-year). Researchers view this as yet another serious warning sign of the threat of global warming. Educational levels: Undergraduate lower division, Undergraduate upper division, Graduate or professional

Bathymetric control of tidewater glacier mass loss in northwest Greenland

It has been suggested that fjord geometry could be an important contributor to the observed mass loss variability in Greenland by modulating the flow of warm water to marine-terminating glaciers. New gravity-derived bathymetry of Greenlandic fjords confirms the link between the grounding line depth and rates of glacier mass loss, a relationship previously predicted only in ice models. We focus on two neighboring glaciers to minimize differences in external forcing and therefore isolate the role of the fjord bathymetry. Tracy Glacier has a deeper grounding line and has been retreating since 1892 with a contemporary mass budget of −1.63 Gt a⁻¹ . Heilprin Glacier has a shallower grounding line depth, a stable ice terminus, and a mass budget of only −0.53 Gt a⁻¹ . Because of its deeper grounding line, Tracy has more ice in contact with warm subsurface water, leaving it more vulnerable to changes in ocean forcing and therefore mass loss

Pulse of the Planet

Akin to a living creature, Earths land, air, oceans, ice, and life fit together into a complex, interlocking system. Space affords a unique vantage point from which to observe the daily, seasonal, and annual changes in Earths systems. Using data from advanced satellites, NASA visualizations portray a majestic, and sometimes violent, natural world and also capture the influences humans have on the planet. Over 80 NASA-related earth science animations created over the past 8 years implementing realtime and non-realtime techniques have been used on this visual journey. Tools used included IDL, Lightwave3D, Final Cut Pro, Performer, Vis5D, and custom software. Educational levels: Undergraduate lower division, Undergraduate upper division, Graduate or professional