Sources of inter-model scatter in TRACMIP, the Tropical Rain belts with an Annual cycle and a Continent Model Intercomparison Project

Abstract

We analyze the source of inter-model scatter in the surface temperature response to quadrupling CO2 in two sets of GCM simulations from the Tropical Rain Belts with an Annual cycle and a Continent Model Intercomparison Project (TRACMIP; Voigt et al, 2016). TRACMIP provides simulations of idealized climates that allow for studying the fundamental dynamics of tropical rainfall and its response to climate change. One configuration is an aquaplanet atmosphere (i.e., with zonally-symmetric boundary conditions) coupled to a slab ocean (AquaCTL and Aqua4x). The other includes an equatorial continent represented by a thin slab ocean with increased surface albedo and decreased evaporation (LandCTL and Land4x).