Effects of Organized Convection Parameterization on the MJO and Precipitation in E3SMv1. Part I: Mesoscale Heating. (21st June 2021)

• Record Type: Journal Article
• Authors: Chen, C.‐C.; Richter, J. H.; Liu, C.; Moncrieff, M. W.; Tang, Q.; Lin, W.; Xie, S.; Rasch, P. J.
• Is Part Of: Journal of advances in modeling earth systems. Volume 13:Number 6(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-21
• Subjects: convection -- MJO -- mesoscale -- precipitation -- Kelvin waves; Geological modeling -- Periodicals; Climatology -- Periodicals; Geochemical modeling -- Periodicals; 551.5011
• DOI: 10.1029/2020MS002401
• Languages: English
• ISSNs: 1942-2466

Abstract

Abstract: Mesoscale organization of convection is typically not represented in global circulation models, and hence its influence on the global circulation is not accounted for. The heating component of a parameterization that represents the dynamical and physical effects of circulations associated with organized convection, referred to as the multiscale coherent structure parameterization (MCSP), is implemented in the Energy Exascale Earth System Model version 1 (E3SMv1). Numerical simulations are conducted to assess its impact on the simulated climate. Besides E3SMv1 simulations, we performed high‐resolution (2 km) simulations using the Weather Research and Forecasting (WRF) Model to determine the temperature tendencies induced by mesoscale convective systems embedded in deep convection. We tuned the free parameters of the MCSP based on the WRF simulations. MCSP heating enhances Kevin wave spectra in E3SMv1, improves the representation of the Madden‐Julian Oscillation, and reduces precipitation biases over the tropical Pacific. Plain Language Summary: Most general circulation models do not account for important circulation changes associated with organized convection. We implement a new parameterization of heating associated with mesoscale circulations in Energy Exascale Earth System Model version 1 (E3SMv1). The parameterization improves the representation of Madden‐Julian Oscillation simulated by E3SMv1 and also reduces the precipitation biases in the tropical West Pacific. Key Points: The heating component of the Multiscale Coherent Structure Parameterization (MCSP) implemented in E3SMv1 MCSP heating improves Madden‐Julian Oscillation and enhances Kelvin waves in E3SMv1 Tropical precipitation biases are significantly reduced