Climate Statistics in Global Simulations of the Atmosphere, from 80 to 2.5 km Grid Spacing

Abstract

Basic climate statistics, such as water and energy budgets, location and width of the Intertropical Convergence Zone (ITCZ), trimodal tropical cloud distribution, position of the polar jet, and land sea contrast, remain either biased in coarse-resolution general circulation models or are tuned. Here, we examine the horizontal resolution dependency of such statistics in a set of global convection-permitting simulations integrated with the ICOsahedral Non-hydrostatic (ICON) model, explicit convection, and grid spacings ranging from 80 km down to 2.5 km. The impact of resolution is quantified by comparing the resolution-induced differences to the spread obtained in an ensemble of eight distinct global storm-resolving models.