Helicopter‐Based Ocean Observations Capture Broad Ocean Heat Intrusions Toward the Totten Ice Shelf

Abstract

Abstract The recent discovery of warm ocean water near the Totten Ice Shelf (TIS) has increased attention to the Sabrina Coast in East Antarctica. We report the result of 6‐day helicopter‐based observations conducted during the 61st Japanese Antarctic Research Expedition (JARE61), revealing warm ocean water (0.5–1°C) occupying a large previously unsampled area of the Sabrina Coast (116.5°E−120°E) below 550–600 m. Along the TIS front, we observe modified Circumpolar Deep Water (mCDW) well above freezing (∼−0.7°C), consistent with previous work. We identify glacial meltwater outflow from the TIS cavity west of 116°E. No signs of mCDW intrusions toward the Moscow University Ice Shelf cavity are observed; however, those observations were limited to only two shallow (∼330 m) profiles. We also highlight the advantages of helicopter‐based observations for accessibility, speed, maneuverability, and cost‐efficiency. The combination of ship‐ and helicopter‐based observations using the JARE61 approach will increase the potential of future polar oceanographic observations.

Keywords

• southern ocean
• ice shelf
• ocean heat intrusions
• airborne measurement
• AXCTD
• AXBT