The Transition to Double‐Celled Circulations in Mock‐Walker Simulations

Abstract Mock‐Walker simulations have the potential to play a key role in a tropical model hierarchy, bridging small‐scale Radiative‐Convective Equilibrium simulations and global models of tropical circulations. We demonstrate that mock‐Walker simulations transition from single‐ to double‐celled ove...

Full description

Saved in:
Bibliographic Details
Main Authors: Nicholas J. Lutsko, Timothy W. Cronin
Format: Article
Language:English
Published: Wiley 2024-07-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2024GL108945
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850272159716343808
author Nicholas J. Lutsko
Timothy W. Cronin
author_facet Nicholas J. Lutsko
Timothy W. Cronin
author_sort Nicholas J. Lutsko
collection DOAJ
description Abstract Mock‐Walker simulations have the potential to play a key role in a tropical model hierarchy, bridging small‐scale Radiative‐Convective Equilibrium simulations and global models of tropical circulations. We demonstrate that mock‐Walker simulations transition from single‐ to double‐celled overturning circulations as mean Sea Surface Temperature (SST) is increased, with the transition occurring near 300 K. The transition is robust to domain geometry and microphysical scheme, and is favored by larger SST gradients. The transition is associated with the development of a mid‐tropospheric minimum in the radiative‐subsidence velocity over the cold pool of the simulations, and is likely reinforced by zonal moisture and temperature fluxes between the warm and cold pools. Several methods of suppressing the transition are investigated, but all set‐ups produce a double‐cell at sufficiently warm mean SSTs. The striking dynamical transition of mock‐Walker simulations dominates their response to warming, though its relevance for observed tropical climate change is unclear.
format Article
id doaj-art-c173d43b040f4e3db3a3494ab323715f
institution OA Journals
issn 0094-8276
1944-8007
language English
publishDate 2024-07-01
publisher Wiley
record_format Article
series Geophysical Research Letters
spelling doaj-art-c173d43b040f4e3db3a3494ab323715f2025-08-20T01:51:55ZengWileyGeophysical Research Letters0094-82761944-80072024-07-015114n/an/a10.1029/2024GL108945The Transition to Double‐Celled Circulations in Mock‐Walker SimulationsNicholas J. Lutsko0Timothy W. Cronin1Scripps Institution of Oceanography University of California at San Diego La Jolla CA USADepartment of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology Cambridge MA USAAbstract Mock‐Walker simulations have the potential to play a key role in a tropical model hierarchy, bridging small‐scale Radiative‐Convective Equilibrium simulations and global models of tropical circulations. We demonstrate that mock‐Walker simulations transition from single‐ to double‐celled overturning circulations as mean Sea Surface Temperature (SST) is increased, with the transition occurring near 300 K. The transition is robust to domain geometry and microphysical scheme, and is favored by larger SST gradients. The transition is associated with the development of a mid‐tropospheric minimum in the radiative‐subsidence velocity over the cold pool of the simulations, and is likely reinforced by zonal moisture and temperature fluxes between the warm and cold pools. Several methods of suppressing the transition are investigated, but all set‐ups produce a double‐cell at sufficiently warm mean SSTs. The striking dynamical transition of mock‐Walker simulations dominates their response to warming, though its relevance for observed tropical climate change is unclear.https://doi.org/10.1029/2024GL108945cloud‐circulation interactionsconvectiontropical Dynamics
spellingShingle Nicholas J. Lutsko
Timothy W. Cronin
The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
Geophysical Research Letters
cloud‐circulation interactions
convection
tropical Dynamics
title The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
title_full The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
title_fullStr The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
title_full_unstemmed The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
title_short The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
title_sort transition to double celled circulations in mock walker simulations
topic cloud‐circulation interactions
convection
tropical Dynamics
url https://doi.org/10.1029/2024GL108945
work_keys_str_mv AT nicholasjlutsko thetransitiontodoublecelledcirculationsinmockwalkersimulations
AT timothywcronin thetransitiontodoublecelledcirculationsinmockwalkersimulations
AT nicholasjlutsko transitiontodoublecelledcirculationsinmockwalkersimulations
AT timothywcronin transitiontodoublecelledcirculationsinmockwalkersimulations