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| Titel |
Towards more physically constrained freshwater injection and its associated impact on paleoclimate variability |
| VerfasserIn |
Ryan Love, Lev Tarasov, Alan Condron |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250146672
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| Publikation (Nr.) |
 EGU/EGU2017-10709.pdf |
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| Zusammenfassung |
| Freshwater forcing (or commonly, “hosing”) has been proposed as a causal mechanism for
the onset of the Younger Dryas period and may play a role in other centennial to millennial
climate events outside the last deglacial period. However, paleoclimate modelling
experiments attempting to infer the role of freshwater forcing have low confidence due to at
least two major issues. First, previous attempts at reproducing the observed variability
through freshwater forcing experiments have often utilized unrealistically large freshwater
volumes and adhoc injection regions. Second, boundary currents and the associated transport
of freshwater sourced from land based ice are to date not resolved (except for a few
exceptions) in paleo model experiments. Despite these limitations, freshwater forcing is
frequently utilised as a means to induce rapid and large scale changes in simulated
paleoclimate.
Few studies have examined the effect of using more realistic freshwater distributions
and/or a concurrent hierarchy of climate models. To quantify the impact of these
freshwater distributions, we sample from the global runoff and calving flux output of the
glacial systems model of Tarasov et. al., 2012 as input into our hierarchy of climate
models. Furthermore, we address the issue of resolution in part by extracting transport
pathways from one of the few experiments that has been conducted at the eddy
permitting scale in the global ocean, that of Condron and Winsor, 2012. With these
enhancements, we re-examine the role of freshwater forcing in the climate system during
glacial conditions. In particular, we quantify the impact of a more realistic freshwater
distribution upon the strength of ocean circulation and heat transport to high latitudes. |
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