SLS — Till Wagner (Scripps)

Modeling iceberg drift and decay in modern and glacial climates

Under global warming, the calving of icebergs into the polar oceans is expected to increase. As a result, the role that icebergs play in Earth’s climate system has received a recent surge of interest, and efforts are underway to explicitly represent icebergs in GCMs. A better understanding of how icebergs drift and decay will help facilitate an accurate representation of icebergs and guide the interpretation of GCM results. In this talk I will present an idealized analytical model that we developed to aid this effort. I will use the model to address (i) which climate model variables are most important to accurately model iceberg evolution and (ii) whether climate models do a good job simulating these variables. I then will turn to episodes of massive iceberg discharge, called Heinrich Events, which occurred during the last glacial period. These events are believed to have had large-scale impacts on the global climate system. However, modeling icebergs that lived and melted more than 10,000 years ago comes with its own challenges, as we will see.