Evaluation of Asian summer precipitation in different configurations of a high-resolution general circulation model in a range of decision-relevant spatial scales

Abstract. High-resolution general circulation models (GCMs) can provide new insights into the simulated distribution of global precipitation. We evaluate how summer precipitation is represented over Asia in simulations with a grid length 14 km. Three were performed: one convection parametrization, explicitly by model's dynamics, and hybrid simulation only shallow mid-level parametrized. mean diurnal cycle amount, frequency, intensity against satellite observations from Climate Prediction Center morphing method (CMORPH). also compare high-resolution coarser that use parametrized convection. The observed averaged spatial scales defined hydrological catchment basins; these natural scale for performing decision-relevant analysis tied to underlying regional physical geography. By selecting basins different sizes, we as function scale. A BAsin-Scale Model Assessment ToolkIt (BASMATI) described, which facilitates this analysis. find there are strong wet biases (locally up 72 mm d?1 at small scales) mountainous regions such Himalayas. explicit worsens existing dry compared simulation. When performed basin scales, bias decreases increase all simulations; lowest-resolution has smallest root squared error CMORPH. In simulations, positive China primarily found be due too frequent intense strongly affected representation convection: produces peak close midday land, whereas closer late afternoon seen observations. At increasing scale, improves when CMORPH; not true any simulations. Some strengths weaknesses GCM found: improved parametrization disabled, interaction flow orography exacerbates produce similar cycles regardless their resolution. need tuning made clear. Our approach evaluating across range widely applicable other GCMs.