Understanding Dynamics and Thermodynamics of ENSO and Its Complexity Simulated by E3SM and Other Climate Models

Technical Report · Wed Jun 28 04:00:00 EDT 2023

DOI:https://doi.org/10.2172/1987593· OSTI ID:1987593

Jin, Fei-Fei ^[1]; Wittenberg, Andrew T. ^[2]; Xie, Shaocheng ^[3]

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1. Univ. of Hawaii, Honolulu, HI (United States); University of Hawaii at Manoa
2. National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States)
3. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

Despite the seeming success of most state-of-the-art climate models in simulating the El Niño-Southern Oscillation (ENSO), there is strong evidence that models achieve realistic levels of ENSO activity do so often for wrong reasons. This is owing to an often occurred near cancelation of large errors in terms of contributions to ENSO growth rate from coupled dynamic and thermodynamic feedback processes. Climate models remain deficient in simulating the observed ENSO’s spatial and temporal complexity that involves interplays of coupled dynamic and thermodynamic feedbacks, interactions across multiple scales, nonlinear processes in the tropical atmosphere and ocean system, biases in mean sate and physical processes, and influences external to equatorial Pacific coupled ENSO dynamics. Our proposed research aims at advancing predictive and process-level understandings of ENSO simulated in E3SM and other climate models under current and future climate conditions with two main objectives: (i) better understanding the aforementioned broad range interactive processes and sources that control fundamental properties of ENSO in E3SM and CIMP6 outputs as well as in observational (reanalysis) data sets, using a hierarchical of coupled dynamical frameworks consisting of theoretical analysis, intermediate complexity modeling, and coupled dynamic diagnostics; (ii) to use this understanding to explore pathways towards improving E3SM’s capability of simulating ENSO and its complexity. More specifically, we will focus on four main thrusts of research: (1) ENSO’s dynamic and thermodynamic feedbacks; (2) the across-scale interactions of ENSO with annual cycle and MJO/WWB/TIW (Madden Julian Oscillation/Westerly Wind Burst/Tropical Instability Wave) activity; (3) key nonlinear processes of ENSO involving atmospheric convective thresholds, nonlinear ocean dynamic heating, and thermocline outcropping; and (4) the impacts of climate mean-state biases/changes and perturbed physical processes on simulated ENSO and its complexity.

• Research Organization: Univ. of Hawaii, Honolulu, HI (United States)
• Sponsoring Organization: USDOE Office of Indian Energy Policy & Programs (IE)
• DOE Contract Number: SC0005110
• OSTI ID: 1987593
• Report Number(s): DOE-UHM--0005110
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES