Researcher Walker Smith of the Virginia Institute of Marine Science, College of William and Mary, has been conducting shipboard studies of biological productivity in Antarctica's Ross Sea for the last three decades. This year he's letting underwater robots do some of the work.
Smith and graduate student Xiao Liu are using a two-year grant from the National Science Foundation to deploy and test a free-swimming underwater glider in the frigid waters of the Ross Sea near the U.S. McMurdo Research Station. The grant also funds efforts by fellow VIMS professor Marjorie Friedrichs to use glider data to help improve computer models of the Ross Sea's physics and biology.
Smith deployed the team's gliderSG503, also know as the Ice Dragonfor its first mission on November 29, 2010. He and colleagues, including investigators from Old Dominion University, launched the 114-pound vehicle through a whale breathing-hole, and then directed it into the open waters of the "polynya" that forms each austral summer when seasonal sea-ice melts from the Ross Sea.
The launch, at a latitude of 77S, is the most southerly glider deployment ever. A short (and unintentional) jog off course also made it the first-ever glider to successfully dive beneath the Ross Ice Shelf.
The Ice Dragon glider in the waters of the Ross Sea.The glider has nowas of January 19, 2011completed 783 dives to depths as great as 700 meters (2,330 feet), traveling a total of 1,402 kilometers (871 miles). It is scheduled to continue yo-yoing back and forth across the Ross Sea polynya until the researchers retrieve it in early February.
Each of the glider's dives lasts about 120 minutes, during which sensors on its fiberglass hull measure water temperature, salinity, levels of dissolved oxygen, and chlorophyll concentrations (the latter a measure of photosynthesis and phytoplankton abundance). At the end of each dive, the glider flips its tail into the air so that its ant
|Contact: David Malmquist|
Virginia Institute of Marine Science