A New Eulerian Iceberg Module for Climate Studies

Abstract Icebergs modulate the effective location of freshwater input from ice sheets into the ocean and therefore play an important role for the climate, especially during times of increased ice discharge (e.g., Heinrich events). None of the models participating in the Paleo Modeling Intercompariso...

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Main Authors: Olga Erokhina, Uwe Mikolajewicz
Format: Article
Language:English
Published: American Geophysical Union (AGU) 2024-03-01
Series:Journal of Advances in Modeling Earth Systems
Subjects:
Online Access:https://doi.org/10.1029/2023MS003807
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author Olga Erokhina
Uwe Mikolajewicz
author_facet Olga Erokhina
Uwe Mikolajewicz
author_sort Olga Erokhina
collection DOAJ
description Abstract Icebergs modulate the effective location of freshwater input from ice sheets into the ocean and therefore play an important role for the climate, especially during times of increased ice discharge (e.g., Heinrich events). None of the models participating in the Paleo Modeling Intercomparison Project simulations of the Last Glacial Maximum or the last deglaciation included icebergs. Here, we present a newly developed dynamic/thermodynamic iceberg module that was specifically designed to be incorporated in climate models used for long‐term climate simulations with interactive ice sheets. In contrast to the widely used Lagrangian iceberg models, it is formulated in an Eulerian framework. This simplifies coupling to ocean models and enhances computational efficiency for glacial climates. In a set of sensitivity experiments, where the module was implemented into an Earth System Model, we validate the model for present‐day climate conditions and test its sensitivity to key parameters. Further, we investigate the effect of iceberg hosing on the Atlantic meridional overturning circulation (AMOC) as compared to traditional freshwater hosing. Varying the hosing rate slowly in time yields a good approximation of the hysteresis curve of the AMOC. We find that the sensitivity of the AMOC to iceberg hosing is stronger than to freshwater hosing in the same ocean point, but weaker as compared to a latitude belt forcing in the North Atlantic. This emphasizes the necessity to include interactive icebergs in long‐term coupled climate simulations to realistically represent melt patterns and the response of the AMOC to freshwater input from melting ice sheets.
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spelling doaj.art-22be37fb48f34fd1ada32f50b00605932024-04-04T21:25:34ZengAmerican Geophysical Union (AGU)Journal of Advances in Modeling Earth Systems1942-24662024-03-01163n/an/a10.1029/2023MS003807A New Eulerian Iceberg Module for Climate StudiesOlga Erokhina0Uwe Mikolajewicz1Max Planck Institute for Meteorology Hamburg GermanyMax Planck Institute for Meteorology Hamburg GermanyAbstract Icebergs modulate the effective location of freshwater input from ice sheets into the ocean and therefore play an important role for the climate, especially during times of increased ice discharge (e.g., Heinrich events). None of the models participating in the Paleo Modeling Intercomparison Project simulations of the Last Glacial Maximum or the last deglaciation included icebergs. Here, we present a newly developed dynamic/thermodynamic iceberg module that was specifically designed to be incorporated in climate models used for long‐term climate simulations with interactive ice sheets. In contrast to the widely used Lagrangian iceberg models, it is formulated in an Eulerian framework. This simplifies coupling to ocean models and enhances computational efficiency for glacial climates. In a set of sensitivity experiments, where the module was implemented into an Earth System Model, we validate the model for present‐day climate conditions and test its sensitivity to key parameters. Further, we investigate the effect of iceberg hosing on the Atlantic meridional overturning circulation (AMOC) as compared to traditional freshwater hosing. Varying the hosing rate slowly in time yields a good approximation of the hysteresis curve of the AMOC. We find that the sensitivity of the AMOC to iceberg hosing is stronger than to freshwater hosing in the same ocean point, but weaker as compared to a latitude belt forcing in the North Atlantic. This emphasizes the necessity to include interactive icebergs in long‐term coupled climate simulations to realistically represent melt patterns and the response of the AMOC to freshwater input from melting ice sheets.https://doi.org/10.1029/2023MS003807icebergoceanMPI‐ESM
spellingShingle Olga Erokhina
Uwe Mikolajewicz
A New Eulerian Iceberg Module for Climate Studies
Journal of Advances in Modeling Earth Systems
iceberg
ocean
MPI‐ESM
title A New Eulerian Iceberg Module for Climate Studies
title_full A New Eulerian Iceberg Module for Climate Studies
title_fullStr A New Eulerian Iceberg Module for Climate Studies
title_full_unstemmed A New Eulerian Iceberg Module for Climate Studies
title_short A New Eulerian Iceberg Module for Climate Studies
title_sort new eulerian iceberg module for climate studies
topic iceberg
ocean
MPI‐ESM
url https://doi.org/10.1029/2023MS003807
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