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gfdl's home page > gfdl on-line bibliography > 1992: Advances in Theoretical Hydrology: A Tribute to Jim Dooge, 159-173

Transient response of a coupled ocean-atmosphere-land surface model to increasing atmospheric carbon dioxide

Manabe, S., R. J. Stouffer, M. J. Spelman, and K. Bryan, 1992: Transient response of a coupled ocean-atmosphere-land surface model to increasing atmospheric carbon dioxide. In Advances in Theoretical Hydrology: A Tribute to Jim Dooge, The Netherlands: Elsevier Science Publishers, 159-173.
Abstract: This study investigates the response of a climate model to a gradual increase of atmospheric carbon dioxide. The model is a general circulation model of the coupled ocean-atmosphere-land surface system with a global computational domain, smoothed geography, and seasonal veriation of insolation. It is found that the simulated increase of sea surface temperature is very slow over the northern North Atlantic and the Circumpolar Ocean of the Southern Hemisphere where the vertical mixing of water penetrates very deeply and the rate of deep water formation is relatively fast. With the exception of these two regions identified above, the distribution of the change in surface temperature of the model is qualitatively similar to the equilibrium response of an atmospheric-mixed layer ocean model, which has been the subject of many previous studies. In most of the Northern Hemisphere, the seasonal dependence of surface air temperature change is also similar to the equilibrium response. For example, the temperature increase is at a maximum over the Arctic Ocean and its surroundings in the late fall and winter, whereas it is at a minimum in summer. However, the increase of surface air temperature and its seasonal variation is very small in the Circumpolar Ocean of the Southern Hemisphere and the northern North Atlantic.
The increase of atmospheric carbon dioxide affects not only the thermal structure of the coupled model but also its hydrologic cycle. For example, the global mean rates of both precipitation and evaporation increase. The increase in evaporation rate is particularly large in low latitudes and decreases with increasing latitudes. On the other hand, the increase in the precipitation rate is substantial in high latitudes due to the increased penetration of warm, moisture-rich air into high latitudes. Thus, the rate of runoff in the subarctic basin increases markedly.
In qualitative agreement with the results of equilibium response studies, soil moisture is reduced in summer over extensive regions of the middle and high latitudes, such as the North American Great Plains, Western Europe, Northern Canada, and Siberia.
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last modified: April 15 2004.