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| Titel |
On the role of sea ice for Southern Ocean stratification |
| VerfasserIn |
F. Alexander Haumann, Matthias Münnich, Nicolas Gruber |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083079
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| Zusammenfassung |
| The formation, subsequent lateral transport, and melt of sea ice represents a key process for
the determination of upper ocean stratification in the Southern Ocean. Sea ice is transported
northward in large parts of the Southern Ocean by strong near-surface winds and melts along
the ice edge south of the polar front, an important upwelling region. Here, it adds freshwater
to the surface ocean, lowers the sea-water density, and possibly reduces upwelling
by increasing the stratification. Consequently, this redistribution of freshwater in
time and space affects the vertical overturning circulation which is an important
determinant of the ocean-atmosphere CO2 exchange and, thus, of the global climate. We
investigate the Southern Ocean sea-ice ocean system using satellite observations
together with simulations with a newly developed regional ocean sea-ice model on the
basis of ROMS. As it is not possible yet to derive sea-ice volume transport from
remote sensing data due to a lack of ice thickness data, we quantify the freshwater
flux exerted by the sea ice from the model and compare it to the observed sea-ice
area transport. This shows that the transport is large in the Weddell and Ross Seas
where sea ice extends to its lowest latitudes. We assess the importance of sea-ice
freshwater transport on the stratification and circulation by comparing this flux to the net
atmospheric freshwater flux from reanalysis data and by perturbing our model simulations. |
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