Unveiling the Influence of the Daily Oceanic (Sub)Mesoscale Thermal Feedback to the Atmosphere
Abstract
Oceanic mesoscale [O(100) km] thermal feedback (TFB) can modify the marine atmospheric boundary layer through two main mechanisms: downward momentum mixing (DMM) and pressure adjustment (PA). In this study, we use ERA5 reanalysis, with the finest spatial resolution available (roughly 25 km globally), and a set of coupled oceanatmosphere model experiments to investigate the extent to which the spatial resolution of oceanic fine-scale structures [O( 10)-( 100) km] influences the TFB mechanisms on a daily time scale in the northwestern tropical Atlantic. We show that the low-level wind magnitude response to sea surface temperature anomalies is controlled by large oceanic mesoscale structures (.100 km), whereas finer structures play a minor role. However, the TFB mechanisms vary considerably depending on whether the mesoscale structures are fully represented or not. The DMM and PA mechanisms are diminished by about 36% and 85%, respectively, when the full range of mesoscale structures in the ocean is resolved. This reduction is associated with both a stronger atmospheric frontogenesis mechanism induced by submesoscale [O( 10) km] oceanic thermal structures and the divergence of submesoscale ocean currents, which is not the case at the large mesoscale. These processes have the potential to exert a destructive influence on the daily oceanic mesoscale TFB by inducing opposite low-level atmospheric vertical velocities, which is particularly enhanced in the case of the PA mechanism. Finally, our findings suggest that climate models must accurately represent fine-scale ocean thermal structures that directly influence TFB mechanisms and potentially affect cloud formation and precipitation patterns.
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BibTeX
@article{conejero2026unveiling,
title = {{Unveiling the Influence of the Daily Oceanic (Sub)Mesoscale Thermal Feedback to the Atmosphere}},
author = {Carlos Conejero and Lionel Renault and Fabien Desbiolles and Hervé Giordani},
journal = {Geophysical Research Letters},
year = {2026},
month = sep,
doi = {10.1175/jpo-d-24-0247.},
url = {https://hal.science/hal-05740128v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Unveiling the Influence of the Daily Oceanic (Sub)Mesoscale Thermal Feedback to the Atmosphere
AU - Carlos Conejero
AU - Lionel Renault
AU - Fabien Desbiolles
AU - Hervé Giordani
PY - 2026
DA - 2026/09/06
JO - Geophysical Research Letters
DO - 10.1175/jpo-d-24-0247.
UR - https://hal.science/hal-05740128v1
AB - Oceanic mesoscale [O(100) km] thermal feedback (TFB) can modify the marine atmospheric boundary layer through two main mechanisms: downward momentum mixing (DMM) and pressure adjustment (PA). In this study, we use ERA5 reanalysis, with the finest spatial resolution available (roughly 25 km globally), and a set of coupled oceanatmosphere model experiments to investigate the extent to which the spatial resolution of oceanic fine-scale structures [O( 10)-( 100) km] influences the TFB mechanisms on a daily time scale in the northwestern tropical Atlantic. We show that the low-level wind magnitude response to sea surface temperature anomalies is controlled by large oceanic mesoscale structures (.100 km), whereas finer structures play a minor role. However, the TFB mechanisms vary considerably depending on whether the mesoscale structures are fully represented or not. The DMM and PA mechanisms are diminished by about 36% and 85%, respectively, when the full range of mesoscale structures in the ocean is resolved. This reduction is associated with both a stronger atmospheric frontogenesis mechanism induced by submesoscale [O( 10) km] oceanic thermal structures and the divergence of submesoscale ocean currents, which is not the case at the large mesoscale. These processes have the potential to exert a destructive influence on the daily oceanic mesoscale TFB by inducing opposite low-level atmospheric vertical velocities, which is particularly enhanced in the case of the PA mechanism. Finally, our findings suggest that climate models must accurately represent fine-scale ocean thermal structures that directly influence TFB mechanisms and potentially affect cloud formation and precipitation patterns.
SN - 0094-8276
SN - 1944-8007
ER -