In:
Paleoceanography, American Geophysical Union (AGU), Vol. 5, No. 1 ( 1990-02), p. 15-41
Abstract:
We have perturbed a simple model of oceanic circulation in a series of sensitivity tests to determine how circulation changes associated with the last glacial maximum could affect observable or potentially observable paleoceanographic parameters. Ultimately, we want to use such paleoceanographic data to construct models of glacial ocean circulation. We have found that the different circulation patterns that we imposed in our sensitivity tests have dramatically different responses for the distribution of PO 4 , O 2 , and ∂ 13 C contents of the oceans. They also produce different levels of low‐latitude productivity. By comparing the coupled responses of several of these paleoceanographic parameters to the responses from the sensitivity tests it is possible to constrain the possible glacial circulation scenarios to a relatively small number. We give, as one example, a case where intermediate turnover is significantly higher than the present and deep ocean turnover has dropped. In addition, exchange of waters between the intermediate‐ and high‐latitude surface ocean is much lower. The result of this scenario is an atmosphere with 60 ppm lower atmospheric CO 2 , low latitudes with about 40% higher productivity, and a change in the planktic/benthic ∂ 13 C contrast of about 0.3‰. When we compare our model to other independent paleoceanographic data, we find that the major point of disagreement is in the distribution of surface water ∂ 13 C in the Antarctic region. We believe that somewhat more complex box models which take open system effects into account will resolve this discrepancy.
Type of Medium:
Online Resource
ISSN:
0883-8305
,
1944-9186
DOI:
10.1029/PA005i001p00015
Language:
English
Publisher:
American Geophysical Union (AGU)
Publication Date:
1990
detail.hit.zdb_id:
637876-6
detail.hit.zdb_id:
2015231-0
detail.hit.zdb_id:
2916554-4
SSG:
16,13
SSG:
13
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