Premium
Thickness of tropical ice and photosynthesis on a snowball earth
Author(s) -
McKay Christopher
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2000gl008525
Subject(s) - snowball earth , sea ice growth processes , atmospheric sciences , cloud cover , photosynthesis , sublimation (psychology) , geology , ice albedo feedback , arctic ice pack , sea ice , environmental science , climatology , antarctic sea ice , glacial period , geomorphology , botany , biology , cloud computing , psychology , computer science , psychotherapist , operating system
On a completely ice‐covered “snowball” Earth the thickness of ice in the tropical regions would be limited by the sunlight penetrating into the ice cover and by the latent heat flux generated by freezing at the ice bottom—the freezing rate would balance the sublimation rate from the top of the ice cover. Heat transfer models of the perennially ice‐covered Antarctic dry valley lakes applied to the snowball Earth indicate that the tropical ice cover would have a thickness of 10 m or less with a corresponding transmissivity of > 0.1%. This light level is adequate for photosynthesis and could explain the survival of the eukaryotic algae.