Evidence for Increased Latent Heat Transport During the Cretaceous (Albian) Greenhouse Warming
Geography and Geology
Quantitative estimates of increased heat transfer by atmospheric H(2)O vapor during the Albian greenhouse warming suggest that the intensified hydrologic cycle played a greater role in warming high latitudes than at present and thus represents a viable alternative to oceanic heat transport. Sphaerosiderite delta(18)O values in paleosols of the North American Cretaceous Western Interior Basin are a proxy for meteoric delta(18)O values, and mass-balance modeling results suggest that Albian precipitation rates exceeded modern rates at both mid and high latitudes. Comparison of modeled Albian and modern precipitation minus evaporation values suggests amplification of the Albian moisture deficit in the tropics and moisture surplus in the mid to high latitudes. The tropical moisture deficit represents an average heat loss of similar to75 W/m(2) at 10degreesN paleolatitude (at present, 21 W/m(2)). The increased precipitation at higher latitudes implies an average heat gain of similar to83 W/ m(2) at 45degreesN (at present, 23 W/m(2)) and of 19 W/m(2) at 75degreesN (at present, 4 W/m(2)). These estimates of increased poleward heat transfer by H(2)O vapor during the Albian may help to explain the reduced equator-to-pole temperature gradients.
(2004). Evidence for Increased Latent Heat Transport During the Cretaceous (Albian) Greenhouse Warming. Geology, 32(12), 1049-1052.
Available at: http://aquila.usm.edu/fac_pubs/2954