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.