Session 59505: Numerical Modeling of the MJO and Subseasonal Convection

Owned by Jim Benedict
Last updated: Sept 10, 2021
2 min read

Session Topic ID: 59505
Session Topic Title: Numerical Modeling of the MJO and Subseasonal Convection

Conference: 10th Symposium on the Madden-Julian Oscillation and Sub-Seasonal Monsoon Variability (conference link)

Accurately simulating the Madden-Julian oscillation (MJO) and subseasonal convective variability in numerical models has been historically difficult, and despite recent progress many challenges remain. Modeling studies improve our understanding of the tropical atmosphere, allow for creative hypothesis testing, and are vital to understanding MJO changes in a warming climate. We invite presentations which discuss advances in modeling the MJO or related modes of tropical convection across a wide range of numerical frameworks, from idealized models to state-of-the-art GCMs. We further welcome work demonstrating novel numerical modeling experiments or new modeling frameworks that might advance our understanding of subseasonal convection.

 

Submissions

  • Jim Benedict [co-authors Charlotte DeMott (CSU) and Brandon Wolding (NOAA)]: Tropical Subseasonal Disturbances in the Energy Exascale Earth System Model Version 2

    • Abstract: Global climate models have long struggled to accurately represent the initiation, propagation, and intensity of the Madden-Julian oscillation (MJO), which presents an urgent challenge given the MJO’s far-reaching impacts on midlatitude weather, tropical cyclones, and precipitation extremes. The U.S. Department of Energy’s Energy Exascale Earth System Model (E3SM) was branched from the Community Earth System Model version 1 (CESM1) and was previously shown to exhibit improved simulation of MJO intensity and propagation relative to CESM1. Here, we present results from newly created historical simulations using E3SM version 2, which suggest a more robust MJO but weakened signals from Kelvin and equatorial Rossby waves compared to E3SM version 1. Process-oriented analyses will be presented to accelerate our understanding of these changes and their relationship to differences in model physics and dynamics-physics coupling between E3SM versions 1 and 2. Investigating sensitivities of these disturbances to model configuration is expected to provide greater insight into mechanisms critical to tropical subseasonal waves.