Using Vertically Integrated Ocean Fields to Characterize Greenland Icebergs' Distribution and Lifetime

Juliana M. Marson, Paul G. Myers, Xianmin Hu, Julien Le Sommer
2018 Geophysical Research Letters  
Icebergs represent approximately half of Greenland's yearly mass loss, having important implications for biological productivity, freshwater fluxes in the ocean, and navigation. This study applies an iceberg model that uses integrated ocean fields (from surface to iceberg keel) to simulate the drift and decay of Greenland icebergs. This version of iceberg model (VERT) is compared with a more widely adopted version (SURF) which only uses surface ocean fields in its equations. We show that
more » ... s in VERT tend to drift along the shelf break, while in SURF they concentrate along the coastline. Additionally, we show that Greenland's southeast coast is the source of ∼60% of the icebergs that cross the interior of the Labrador Sea-a region that stages buoyancy-driven convection and is, therefore, sensitive to freshwater input. Plain Language Summary Thousands of icebergs break off from Greenland every year, threatening navigation along North America's east coast. Since it is difficult to monitor individual icebergs, computer simulations are useful to help us understand their common pathways and, potentially, to predict when and from where icebergs come from. In this study, we use an improved iceberg model (one that uses the variations of ocean currents and temperature with depth to interact with icebergs) to simulate Greenland icebergs' distribution and their persistence in different regions of the North Atlantic. We show that this improved version better reproduces iceberg pathways observed in the past. Moreover, we find that icebergs breaking off from the southeast part of Greenland compose most icebergs reaching the middle of the Labrador Sea-a region where iceberg melt may affect ocean circulation and, consequently, heat distribution from tropics to poles. This means that an increasing volume of icebergs coming out of this particular region in a warmer world might have an effect back on the climate.
doi:10.1029/2018gl077676 fatcat:4or22zhgkbfivbhovtyolo25zy