Monsoons across Epochs: Diagnosing Monsoonal Circulations across Warm, Greenhouse Climates as Simulated by the Community Climate System Model (CCSM3)

The nature of monsoons has been studied extensively in the scientific community because of its significance in dominating regional climate and weather. Analyzing the underlying mechanisms behind the monsoon in past climates, in particular, warm greenhouse climates, give us a deeper understanding of what drives the monsoon for today and potentially for the future. In this study, we use the Community Climate System Model (CCSM3) to analyze global monsoonal circulations for three warm, greenhouse climates including the Late Permian (250Ma), the Latest Cretaceous (65Ma), and the Paleocene-Eocene Thermal Maximum (55Ma). A suite of simulations will be presented where surface and boundary forcings appropriate for each time period are used as well as sensitivity studies designed to test the role of CO2 and paleogeography. Paleogeography, CO2 levels, and, consequently the location of the tropical oceanic warm pools will be studied as potential elements for obtaining key wind patterns and manifestation of monsoonal precipitation.