ARE ATMOSPHERIC CO2 CONTENT AND PLEISTOCENE CLIMATE CONNECTED BY WIND-SPEED OVER A POLAR MEDITERRANEAN-SEA

Authors
Citation
Rs. Keir, ARE ATMOSPHERIC CO2 CONTENT AND PLEISTOCENE CLIMATE CONNECTED BY WIND-SPEED OVER A POLAR MEDITERRANEAN-SEA, Global and planetary change, 8(1-2), 1993, pp. 59-68
Citations number
34
Categorie Soggetti
Geosciences, Interdisciplinary
Journal title
ISSN journal
09218181
Volume
8
Issue
1-2
Year of publication
1993
Pages
59 - 68
Database
ISI
SICI code
0921-8181(1993)8:1-2<59:AACCAP>2.0.ZU;2-0
Abstract
Dust and sea-salt records in polar ice cores indicate that the climate has been windier during ice-ages, and therefore the rate of gas excha nge between the atmosphere and ocean should be greater in glacial peri ods. Increased gas exchange between the atmosphere and poleward-advect ed, sinking cold water due to higher wind speeds could make the solubi lity pump more efficient, and this would decrease atmospheric CO2. To illustrate how this might contribute to atmospheric CO2 change over th e last 150 kyr, the marine Na-concentration in the Vostok ice core is used as a logarithmic proxy for relative wind speed, from which gas pi ston velocities relative to the present are estimated. The effect of t he cold water piston velocity on atmospheric CO2 is then calculated ac cording to an atmosphere-surface ocean box model. As a result, the sol ubility pump lowers atmospheric CO2 about 50 ppm during oxygen isotope stages 2-4 and about 40 ppm during stage 5a-d. Unlike various nutrien t rearranging mechanisms, the solubility pump produces little fraction ation of carbon isotopes between the surface and deep ocean. Combining wind-induced solubility and nutrient-based effects, using DELTAdeltaC -13 in deep-sea core V19-30 as a proxy of the latter, produces a recor d of atmospheric CO, which is similar to that observed in the Vostok i ce core.