Observed equatorward propagation and chimney effect of near‐inertial waves in the midlatitude ocean
Observed equatorward propagation and chimney effect of near‐inertial waves in the midlatitude ocean
The propagation characteristics of near-inertial waves (NIWs) and how mesoscale and submesoscale processes affect the waves' vertical penetration are investigated using observations from a mooring array located in the northeast Atlantic. The year-long observations show that near-inertial motions are mainly generated by local wind forcing, and that they radiate equatorward and downward following several strong wind events (wind stress ≳0.5 N m
−2). Observational estimates of horizontal group speed typically exceed those of vertical group speed by two orders of magnitude, consistent with predictions from the dispersion relation. Enhanced near-inertial kinetic energy and vertical shear are found only in mesoscale anticyclones with Rossby number of O(0.1). By contrast, submesoscale motions with order one Rossby number have little effect on the trapping and vertical penetration of NIWs, due to their smaller horizontal scales, shorter time scales, and confined vertical extent compared to mesoscale eddies.
chimney effect, mesoscale motions, near-inertial waves, submesoscale motions
Yu, Xiaolong
3ffa551d-f57e-4f49-a130-475e43039c75
Naveira Garabato, Alberto C.
97c0e923-f076-4b38-b89b-938e11cea7a6
Vic, Clément
408e7f4a-468f-4139-90a6-3a95228ad758
Gula, Jonathan
7f8ad0bd-b6fc-4bd1-beef-d8b298fac0ef
Savage, Anna C.
444b62d2-0db1-4d92-84ea-ddef7056f3ca
Wang, Jinbo
cf7e10eb-96a5-4381-adcb-3bd6f5d8ec41
Waterhouse, Amy F.
f08abcd9-59c1-427a-9853-ffe788ff1732
Mackinnon, Jennifer A.
724d9cf9-bbdf-4a87-8834-e3227b500201
16 July 2022
Yu, Xiaolong
3ffa551d-f57e-4f49-a130-475e43039c75
Naveira Garabato, Alberto C.
97c0e923-f076-4b38-b89b-938e11cea7a6
Vic, Clément
408e7f4a-468f-4139-90a6-3a95228ad758
Gula, Jonathan
7f8ad0bd-b6fc-4bd1-beef-d8b298fac0ef
Savage, Anna C.
444b62d2-0db1-4d92-84ea-ddef7056f3ca
Wang, Jinbo
cf7e10eb-96a5-4381-adcb-3bd6f5d8ec41
Waterhouse, Amy F.
f08abcd9-59c1-427a-9853-ffe788ff1732
Mackinnon, Jennifer A.
724d9cf9-bbdf-4a87-8834-e3227b500201
Yu, Xiaolong, Naveira Garabato, Alberto C., Vic, Clément, Gula, Jonathan, Savage, Anna C., Wang, Jinbo, Waterhouse, Amy F. and Mackinnon, Jennifer A.
(2022)
Observed equatorward propagation and chimney effect of near‐inertial waves in the midlatitude ocean.
Geophysical Research Letters, 49 (13), [e2022GL098522].
(doi:10.1029/2022GL098522).
Abstract
The propagation characteristics of near-inertial waves (NIWs) and how mesoscale and submesoscale processes affect the waves' vertical penetration are investigated using observations from a mooring array located in the northeast Atlantic. The year-long observations show that near-inertial motions are mainly generated by local wind forcing, and that they radiate equatorward and downward following several strong wind events (wind stress ≳0.5 N m
−2). Observational estimates of horizontal group speed typically exceed those of vertical group speed by two orders of magnitude, consistent with predictions from the dispersion relation. Enhanced near-inertial kinetic energy and vertical shear are found only in mesoscale anticyclones with Rossby number of O(0.1). By contrast, submesoscale motions with order one Rossby number have little effect on the trapping and vertical penetration of NIWs, due to their smaller horizontal scales, shorter time scales, and confined vertical extent compared to mesoscale eddies.
Text
Observed equatorward propagation and chimney effect
- Accepted Manuscript
More information
Accepted/In Press date: 11 June 2022
e-pub ahead of print date: 25 June 2022
Published date: 16 July 2022
Additional Information:
Funding Information:
We are grateful to the officers, crew, scientists, and technicians of the RRS , RRS , and R/V , for their hard work in deploying and recovering the OSMOSIS moorings and gliders. This work was funded by grants from the Natural Environmental Research Council (NE/I019999/1 and NE/I01993X/1). We thank two anonymous reviewers for their insightful feedback. Discovery James Cook Celtic Explorer
Publisher Copyright:
© 2022. American Geophysical Union. All Rights Reserved.
Keywords:
chimney effect, mesoscale motions, near-inertial waves, submesoscale motions
Identifiers
Local EPrints ID: 469387
URI: http://eprints.soton.ac.uk/id/eprint/469387
ISSN: 0094-8276
PURE UUID: 89050681-3cf7-41fb-9a48-e242ad3ff98f
Catalogue record
Date deposited: 14 Sep 2022 16:40
Last modified: 06 Jun 2024 01:43
Export record
Altmetrics
Contributors
Author:
Xiaolong Yu
Author:
Clément Vic
Author:
Jonathan Gula
Author:
Anna C. Savage
Author:
Jinbo Wang
Author:
Amy F. Waterhouse
Author:
Jennifer A. Mackinnon
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
