Robust Observational Quantification of the Contribution of Mesoscale Convective Systems to Rainfall in the Tropics

Abstract

Satellite estimation of precipitation and satellite-derived statistics of mesoscale convective systems (MCS) are analyzed conjunctively to quantify the contribution of the various types of MCS to the water budget of the tropics. This study focuses on two main mesoscale characteristics of the systems: duration and propagation. Overall, the systems lasting more than 12 h are shown to account for around 75% of the tropical rainfall, and 60% of the rainfall is due to systems traveling more than 250 km, a typical GCM grid. A number of regional features are also revealed by factoring in the convective systems’ morphological parameters in the water budget computation. These findings support the challenging effort to account for such mesoscale features when considering the theory on the future evolution of the water budget as well as the physical parameterizations of climate models. Finally, this analysis provides a simple metric for evaluating high-resolution numerical simulations of the tropical water budget. Furthermore, results are shown to be robust to the selection of the satellite rainfall products.

Different Representation of Mesoscale Convective Systems in Convection-Permitting and Convection-Parameterizing NWP Models and Its Implications for Large-Scale Forecast Evolution

“…For ICON-HiRes, this contribution amounted to 65%. These values were smaller than those reported in other studies (e.g., [40,43]), but should be considered as low estimates because some evidently westward-propagating systems were missed by the identification algorithm (cf. Figure 1).…”

Footprint of Tropical Mesoscale Convective System Variability on Stratospheric Water Vapor

“…Owing to their central role in the tropical energy and water budget, the study of MCS has benefited from extensive researches using campaign measurements, satellite observations, and model simulations (Houze, 2004;Houze et al, 2015;Mohr & Zipser, 1996;Moncrieff et al, 2017;Moncrieff, 2019;Pope et al, 2009;Roca et al, 2014;Tan et al, 2015;Tselioudis et al, 2010). However, little attention has been paid to variations of tropical MCSs on a global scale.…”

New Cloud System Metrics to Assess Bulk Ice Cloud Schemes in a GCM

“…For a more process‐oriented evaluation, we use a novel cloud system concept (Protopapadaki et al, ), which allows to relate the anvil properties to those of the convective cores. While classic cloud system approaches are based on the infrared (IR) brightness temperature and therefore only consider the thicker anvil parts (e.g., Liu et al, ; Machado et al, ; Roca et al, ; Yuan & Houze, ), this new concept uses two separate variables to construct the cloud systems: pressure (or height), p cld , and emissivity, ε cld . The latter allows to distinguish between convective core, cirrus anvil, and thin cirrus within these systems.…”