Convectively Coupled Equatorial Waves in a Global Storm‐Resolving Model
- 1Max Planck Institute for Meteorology Hamburg Germany
- 2Department of Atmospheric and Oceanic Sciences University of Wisconsin Madison WI USA
- 3Climate Prediction Research Center Seoul National University Seoul South Korea
Abstract
We show how reducing the fall speeds of rain and ice leads to reduced biases of Convectively Coupled Equatorial Waves (CCEWs) in convection‐resolving configurations of the Icosahedral Non‐hydrostatic Model (ICON). In particular, reducing the fall speeds of rain and ice leads to stronger activity over the wavenumbers and frequencies associated with convectively coupled Kelvin waves, inertio‐gravity waves, mixed Rossby‐gravity waves, equatorial Rossby waves, and the Madden‐Julian oscillation, and to weaker activity of tropical depressions. The changes in CCEW activity are mediated by changes in the frequency of mesoscale convection profiles. Reducing the fall speeds increases the frequency of bottom‐heavy and top‐heavy mesoscale convection profiles and decreases the frequency of mid‐heavy mesoscale convection profiles. In turn, changes to the mesoscale convective profiles are reflected in the ability of the model to develop the tilt and top‐heaviness of CCEWs. Reductions in the fall speeds also increase precipitation over the warm pool region, possibly allowing for a stronger equatorial forcing of convectively coupled Kelvin waves. Our findings suggest that the representation of CCEWs within ICON agrees with their observed multiscale structure.
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BibTeX
@article{ortega2026convectively,
title = {{Convectively Coupled Equatorial Waves in a Global Storm‐Resolving Model}},
author = {Sebastián Ortega and Hans Segura and Víctor C. Mayta and Romain Fiévet and Angel Peinado and Junhong Lee and Marco A. Giorgetta and Bjorn Stevens},
journal = {Journal of Advances in Modeling Earth Systems},
year = {2026},
month = oct,
doi = {10.1029/2026ms005799},
url = {https://doi.org/10.1029/2026ms005799},
note = {CC BY},
}
RIS
TY - JOUR
TI - Convectively Coupled Equatorial Waves in a Global Storm‐Resolving Model
AU - Sebastián Ortega
AU - Hans Segura
AU - Víctor C. Mayta
AU - Romain Fiévet
AU - Angel Peinado
AU - Junhong Lee
AU - Marco A. Giorgetta
AU - Bjorn Stevens
PY - 2026
DA - 2026/10/28
JO - Journal of Advances in Modeling Earth Systems
DO - 10.1029/2026ms005799
UR - https://doi.org/10.1029/2026ms005799
AB - We show how reducing the fall speeds of rain and ice leads to reduced biases of Convectively Coupled Equatorial Waves (CCEWs) in convection‐resolving configurations of the Icosahedral Non‐hydrostatic Model (ICON). In particular, reducing the fall speeds of rain and ice leads to stronger activity over the wavenumbers and frequencies associated with convectively coupled Kelvin waves, inertio‐gravity waves, mixed Rossby‐gravity waves, equatorial Rossby waves, and the Madden‐Julian oscillation, and to weaker activity of tropical depressions. The changes in CCEW activity are mediated by changes in the frequency of mesoscale convection profiles. Reducing the fall speeds increases the frequency of bottom‐heavy and top‐heavy mesoscale convection profiles and decreases the frequency of mid‐heavy mesoscale convection profiles. In turn, changes to the mesoscale convective profiles are reflected in the ability of the model to develop the tilt and top‐heaviness of CCEWs. Reductions in the fall speeds also increase precipitation over the warm pool region, possibly allowing for a stronger equatorial forcing of convectively coupled Kelvin waves. Our findings suggest that the representation of CCEWs within ICON agrees with their observed multiscale structure.
SN - 1942-2466
ER -