Ice streams flowing from the Antarctic continent come in contact with the ocean where they cross the grounding line and begin to float as ice shelves. Nearly 40% of the sea surface of the Antarctic continental shelf is covered by ice shelves ranging in size up to the Texas-sized Ross Ice Shelf. These ice shelves gain mass from the inflow of continental ice, surface accumulation and freezing of marine ice on their undersides and lose mass primarily from iceberg calving and basal melting. Transport of the basal melt water out into the open ocean has been proposed as a significant source of dissolved iron and thus a major control on phytoplankton growth over the productive Antarctic continental shelf. Changes in ice shelf structure due to basal melt have also received much attention recently because of the suggestion that the ice shelves buttress the massive continental ice sheets and reduction of the ice shelves will result in a greater flow of continental ice into the ocean.

The CMIP5 generation of coupled climate models did not explicitly model ice shelves, but several regional and circum-Antarctic ocean models do and these have been used to simulate current and projected states of ice shelf basal melt. Results will be presented from different regional ocean/sea-ice/ice shelf models of coastal seas around Antarctica to show the importance of model resolution in getting ocean heat to the base of the floating ice shelves and to examine the effects of idealized and climate model projected changes in the winds on ice shelf basal melt.

After spending several years writing software for flight simulators, Mr. Dinniman went back to school where he received a M.S. from the University of Maryland and first heard about ocean modeling. He then worked for two years at the NASA Goddard Space Flight Center before coming to CCPO. Mr. Dinniman's research interests are in using computer models to study different bodies of water ranging from the Pacific and Southern Oceans to the Chesapeake Bay.

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