A 6 month temperature record collected below McMurdo Ice Shelf in 2011-2012 shows the temporal and spatial structure of the summertime warm water signal that penetrates beneath the ice shelf. The strength and duration of the warm water intrusion suggest an annual melt rate at Windless Bight of 0.71 m/yr. A Ross Sea numerical model demonstrates a seasonal warm water pathway leading from the west side of the Ross Sea Polynya (RSP) toward McMurdo Sound. The warm water enters McMurdo Sound, subducts beneath the ice shelf and causes accelerated summer melting. Temperature data were recorded using Distributed Temperature Sensing fiber optics, which gives a vertical temperature profile at a 1 m vertical resolution. This study constitutes one of the first successful implementations of this technology in Polar Regions
