The climate change following the Genesis Flood provides a likely catastrophic mechanism for an ice age. The Flood was a tremendous tectonic and volcanic event. Large amounts of volcanic aerosols would remain in the atmosphere following the Flood, generating a large temperature drop over land by reflecting much solar radiation back to space. Volcanic aerosols would likely be replenished in the atmosphere for hundreds of years following the Flood, due to high post-Flood volcanism, which is indicated in Pleistocene sediments. The moisture would be provided by strong evaporation from a much warmer ocean, following the Flood. The warm ocean is a consequence of a warmer pre-Flood climate and the release of hot subterranean water during the eruption of "all the fountains of the great deep" (Genesis 7:11). The added quantity of water must have been large to cover all the pre-Flood mountains, which were lower than today. Evaporation over the ocean is proportional to how cool, dry, and unstable the air is, and how fast the wind blows. Indirectly, it is proportional to sea surface temperature. A 10 degree C air-sea temperature difference, with a relative humidity of 50%, will evaporate seven times more water at a sea surface temperature of 30 degrees C than at 0 degrees C. Thus, the areas of greatest evaporation would be at higher latitudes and off the east coast of Northern Hemisphere continents. Focusing on northeast North America, the combination of cool land and warm ocean would cause the high level winds and a main storm track to be parallel to the east coast, by the thermal wind equation. Storm after storm would develop near the eastern shoreline, similar to modern-day Northeasters, over the continent. Once a snow cover is established, more solar radiation is reflected back to space, reinforcing the cooling over land, and compensating the volcanic lulls.
The ice sheet will grow as long as the large supply of moisture is available, which depends upon the warmth of the ocean. Thus, the time to reach maximum ice volume will depend upon the cooling time of the ocean. This can be found from the heat balance equation for the ocean, with reasonable assumptions of post-Flood climatology and initial and final average ocean temperatures. However, the heat lost from the ocean would be added to the atmosphere, which would slow the oceanic cooling with cool summers and warm winters. The time to reach maximum ice volume must also consider the heat balance of the post-Flood atmosphere, which would strongly depend upon the severity of volcanic activity. Considering ranges of volcanism and the possible variations in the terms of the balance equations, the time for glacial maximum ranges from 250 to 1300 years.
The average ice depth at glacial maximum is proportional to the total evaporation from the warm ocean at mid and high latitudes, and the transport of moisture from lower latitudes. Since most snow in winter storms falls in the colder portion of the storm, twice the precipitation was assumed to fall over the cold land than over the ocean. Some of the moisture, re-evaporated from non-glaciated land, would end up as snow on the ice sheet, but this effect should be mostly balanced by summer runoff. The average depth of ice was calculated at roughly half uniformitarian estimates. The latter are really unknown. As Bloom states, "Unfortunately, few facts about its thickness are known . . . we must turn to analogy and theory. . . ."
The time to melt an ice sheet at mid-latitudes is surprisingly short, once the copious moisture source is gone. It depends upon the energy balance over a snow or ice cover. Several additional factors would have enhanced melting. Crevassing would increase the absorption of solar radiation, by providing more surface area. The climate would be colder and drier than at present, with strong dusty storms that would tend to track along the ice sheet boundary. The extensive loess sheets south of and within the periphery of the past ice sheet attest to this. Dust settling on the ice would greatly increase the solar absorption and melting. A mountain snowfield in Japan was observed to absorb 85% of the solar radiation after 4000 ppm of pollution dust had settled on its surface.
