Evaluation of Simulated Climate in Lower Latitude Regions during the Mid-Pliocene Warm Period Using Paleovegetation Data

Abstract

Paleovegetational dataset during the mid-Pliocene warm period (MPWP) in lower latitudes are applied to evaluation for annual-mean MPWP climate simulated by a general circulation model (GCM). GCM-derived warmer climate in mid-latitude and wetter condition in subtropics during MPWP are generally confirmed by the terrestrial proxy data. The comparisons of their general patterns reveal an ability of GCM to predict the sustained-warmer climate under the different forcings from present day. In comparison to the proxy data, the enhanced rainfall over semi-arid regions in accordance with the alteration of Hadley/Walker circulation in MPWP is supported but the extent may be partially underestimated. The paleobotanical data in the lower latitudes indicate an importance of interactive response of vegetation to climate under the equilibrium warmer state of the earth system.