Statistics and Mechanisms of Convective Organization in a 12 km Downscaled Global Reanalysis

Friday, 18 December 2015: 14:50
3004 (Moscone West)
Nathan Arnold, Goddard Earth Sciences Technology and Research, Greenbelt, MD, United States
Here we examine meso- to synoptic-scale convective organization in a global non-hydrostatic simulation using GEOS-5 with 12 km horizontal grid spacing. Tropical convective clusters are identified using simple metrics based on Tobin et al. (2012), and statistics are gathered on their spatial scale and duration. Moisture and moist static energy (MSE) budgets are used to quantify the extent to which clusters are supported by radiative and surface flux feedbacks and variations in gross moist stability. We will present relationships between cluster characteristics (scale, duration, and MSE dynamics) and the large scale state (shear, humidity, and radiative balance). This work has applications in the parameterization of convective organization in GCMs, and in better understanding the connection between the convective aggregation seen in idealized cloud resolving model simulations and organization observed in nature.