Figure showing changes in ocean surface temperature as a large iceberg and several small icebergs break off an ice shelf
Changes in ocean surface temperature as a large iceberg and several small icebergs break off an ice shelf. Snapshots are taken 7, 15 and 50 days after calving. Color shows temperature change, in degrees Celsius, relative to conditions before the icebergs calved. Gray shades show ice thickness, in meters. Credit: Stern et al. [2019], Figure 2
Source: Journal of Geophysical Research: Oceans

Large tabular icebergs that break off ice shelves in Antarctica drift north into the Southern Ocean. Standard ocean models assume that, regardless of its size, an iceberg can be treated as a “passive tracer” that follows the ocean currents that would be predicted in a model which ignored the iceberg. However, a large iceberg modifies the ocean around itself in ways that affect its path and the rate at which it melts.

Stern et al. [2019] describe a new model for the ocean, ice shelves, and icebergs that includes the feedbacks between the ocean and the ice as an iceberg breaks away from an ice shelf and begins to drift into the open ocean. Their model shows how the three-dimensional currents that are generated around the iceberg affect melting rates, iceberg drift and rotation, and the transport of water that is trapped under the iceberg.

This new approach to modeling icebergs should lead to better predictions of how ice that is lost from the Antarctic Ice Sheet is carried away from the Antarctic coast to influence the Southern Ocean’s stratification, sea ice and ecosystems, and its role in global climate.

Citation: Stern, A. A., Adcroft, A., & Sergienko, O. V. [2019]. Modeling ice shelf cavities and tabular icebergs using lagrangian elements. Journal of Geophysical Research: Oceans, 124.

—Laurence Padman, Editor, JGR: Oceans

Text © 2019. The authors. CC BY-NC-ND 3.0
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