Reply to J. G. Lockwood

Abstract

The comments made by Dr Lockwood raise interesting questions regarding the energy balance accompanying the ice ages, but also reveal several misunderstandings.

Contrary to his second sentence, I do not "assume that the latent heat of fusion released during the growth of the Wiirm/Wisconsin conti- nental ice-sheets was absorbed by the oceans, since there might be radiative balance at the top of the atmosphere", but rather maintain that if a radiative balance were to prevail at all times (which I strongly doubt), then the latent heat must be absorbed by the oceans. I further open for con- sideration the possibility suggested by preliminary theoretical results (Saltzman and Vernekar, 1975, henceforth called S-V) that, contrary to our intuitions, the imbalance could be such that the net radiation is negative during an interglacial period and positive during a glacial period. In this case, the temperature of the ocean should be rising during a significant part of the period of glacial growth and during maximum glaciation, consistent with Newell's (1974) scenario. There is no question that if paleotemperature analyses of the deeper ocean water fail to reveal a relative warmth during the ice age, there must be a negative radiation balance during glacial growth and mechanisms such as described by Lockwood could very well be dominant.