Glacial cycles modeling

Gallee, H., van Ypersele, J.P., Fichefet, T., Marsiat, I., Tricot, C., Berger, A. 1992 Simulation of the last glacial cycle by a coupled, sectorial averaged climate-ice sheet model. 2. response ot insolation and C02 variations /. Geosphys. Res. 97, No. D14,15713-15740... 

Gallcc, J.-R, van Ypcrsclc, J. P., Fichefct, T., Marsiat, L, Tricot, C., and Pierger, A. (1992). Simulation of the la.st glacial cycle by a coupled,, sec-torially averaged climate-ice sheet model. Part 2. Response to insolation and CO, variations. /. Geopliys. Rei. 97, 15713-15740. 

Figure 2. Modelled ground surface temperature at Whiteshell through the last glacial cycle.

In addition to the challenge of modeling the mid-Pleistocene transition, no model has successfully reproduced the relatively clean 41000-year cycles preceding the transition, hollowing the transition, the models only exhibit a good match with the observed glacial cycles when forced with reconstructed CO2 from Antarctic ice cores together with orbital insolation. 

Figure 3 Results from a simple three-box ocean carbon cycle model, (a) The physical circulation and modeled radiocarbon (A C) values, (b) The model biogeochemical fields, ocean DIG, and phosphate PO4) and atmospheric pCOa. From Toggweiler JR and Sarmiento JL, Glacial to inter-glacial changes in atmospheric carbon dioxide The critical role of ocean surface waters in high latitudes, The Carbon Cycle and Atmospheric CO2. Natural Variations Archean to Present, Sundquist ET and Broecker WS (eds.), pp. 163-184, 1985, Copyright [1985]. American Geophysical Union. Adapted by permission of American Geophysical Union.

Figure 10.40. Comparison of a model calculation (solid line) for glacial-interglacial changes in atmospheric CO2 with the observed CO2 record (dashed line) from the Vostok ice core. The model is that of the CO2-O2 geochemical cycle in Figure 10.38.

Figure 44 Tentative model of global ocean carbonate cycle. Fluxes are in units of lO molCyr as (Ca,Mg)C03 and represent estimates of fluxes averaged over the most recent glacial-interglacial transition (after Mackenzie and Morse, 1992).

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