Mid-Cretaceous Continental Surface Temperatures: Are High CO2 Concentrations Needed to Simulate Above-Freezing Winter Conditions?
- E.T. Sundquist and
- W.S. Broecker
Published Online: 18 MAR 2013
Copyright 1985 by the American Geophysical Union.
The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present
How to Cite
Schneider, S. H., Thompson, S. L. and Barron, E. J. (1985) Mid-Cretaceous Continental Surface Temperatures: Are High CO2 Concentrations Needed to Simulate Above-Freezing Winter Conditions?, in The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present (eds E.T. Sundquist and W.S. Broecker), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM032p0554
- Published Online: 18 MAR 2013
- Published Print: 1 JAN 1985
Print ISBN: 9780875900605
Online ISBN: 9781118664322
- Carbon cycle (Biogeochemistry)—Congresses;
- Atmospheric carbon dioxide—Congresses;
- Geological time—Congresses;
- Geology, Stratigraphic—Congresses
We have found that mid-Cretaceous paleogeography (for 100 million years ago) and very efficient oceanic mixing (e.g., holding all oceanic surface temperatures fixed at 293°K) together are still insufficient to produce above-freezing (or even near-freezing) surface temperatures in our model in mid- to high-latitude continental interiors in midwinter. For mean annual solar forcing and a no-heat capacity, no-ocean transport “swamp” ocean, Barron and Washington (1984) had obtained high northern latitude land and oceanic surface temperatures in the 270°–280° K range, warmer in the high-latitude midcontinents in the northern hemisphere than the much warmer all-293°K oceanic case presented here. In our all-293°K case, the equator-to-pole ocean surface temperature gradient is very weak, as is the vigor of atmospheric circulation, which, in turn, provides insufficient ocean to land atmospheric heat transport to mitigate midwinter continental radiative cooling. Increasing the atmospheric air temperature gradient from equator to pole can increase atmospheric circulation and moderate somewhat the midcontinental cold temperatures. Nevertheless, all the cases we have considered suggest that midwinter high-latitude freezing is still present, particularly in regions of assumed higher topography.