Baroclinic Instability in the Presence of Convection
Baroclinic mixed-layer instabilities have recently been recognized as an important source of submesoscale energy in deep winter mixed layers. While the focus has so far been on the balanced dynamics of these instabilities, they occur in and depend on an environment shaped by atmospherically forced s...
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| Format: | Article |
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American Meteorological Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/118435 https://orcid.org/0000-0002-3736-1956 |
| _version_ | 1811075188942438400 |
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| author | Callies, Jörn Ferrari, Raffaele |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Callies, Jörn Ferrari, Raffaele |
| author_sort | Callies, Jörn |
| collection | MIT |
| description | Baroclinic mixed-layer instabilities have recently been recognized as an important source of submesoscale energy in deep winter mixed layers. While the focus has so far been on the balanced dynamics of these instabilities, they occur in and depend on an environment shaped by atmospherically forced small-scale turbulence. In this study, idealized numerical simulations are presented that allow the development of both baroclinic instability and convective small-scale turbulence, with simple control over the relative strength. If the convection is only weakly forced, baroclinic instability restratifies the layer and shuts off convection, as expected. With increased forcing, however, it is found that baroclinic instabilities are remarkably resilient to the presence of convection. Even if the instability is too weak to restratify the layer and shut off convection, the instability still grows in the convecting environment and generates baroclinic eddies and fronts. This suggests that despite the vigorous atmospherically forced small-scale turbulence in winter mixed layers, baroclinic instabilities can persistently grow, generate balanced submesoscale turbulence, and modify the bulk properties of the upper ocean. Keywords: Baroclinic flows; Convection; Ocean dynamics; Oceanic mixed layer |
| first_indexed | 2024-09-23T10:01:55Z |
| format | Article |
| id | mit-1721.1/118435 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T10:01:55Z |
| publishDate | 2018 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/1184352022-09-26T15:19:16Z Baroclinic Instability in the Presence of Convection Callies, Jörn Ferrari, Raffaele Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ferrari, Raffaele Baroclinic mixed-layer instabilities have recently been recognized as an important source of submesoscale energy in deep winter mixed layers. While the focus has so far been on the balanced dynamics of these instabilities, they occur in and depend on an environment shaped by atmospherically forced small-scale turbulence. In this study, idealized numerical simulations are presented that allow the development of both baroclinic instability and convective small-scale turbulence, with simple control over the relative strength. If the convection is only weakly forced, baroclinic instability restratifies the layer and shuts off convection, as expected. With increased forcing, however, it is found that baroclinic instabilities are remarkably resilient to the presence of convection. Even if the instability is too weak to restratify the layer and shut off convection, the instability still grows in the convecting environment and generates baroclinic eddies and fronts. This suggests that despite the vigorous atmospherically forced small-scale turbulence in winter mixed layers, baroclinic instabilities can persistently grow, generate balanced submesoscale turbulence, and modify the bulk properties of the upper ocean. Keywords: Baroclinic flows; Convection; Ocean dynamics; Oceanic mixed layer National Science Foundation (U.S.) (Grant OCE-1233832) 2018-10-11T15:52:11Z 2018-10-11T15:52:11Z 2018-01 2017-03 2018-09-25T16:45:57Z Article http://purl.org/eprint/type/JournalArticle 0022-3670 1520-0485 http://hdl.handle.net/1721.1/118435 Callies, Jörn, and Raffaele Ferrari. “Baroclinic Instability in the Presence of Convection.” Journal of Physical Oceanography 48, 1 (January 2018): 45–60 © 2018 American Meteorological Society https://orcid.org/0000-0002-3736-1956 http://dx.doi.org/10.1175/JPO-D-17-0028.1 Journal of Physical Oceanography Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Callies, Jörn Ferrari, Raffaele Baroclinic Instability in the Presence of Convection |
| title | Baroclinic Instability in the Presence of Convection |
| title_full | Baroclinic Instability in the Presence of Convection |
| title_fullStr | Baroclinic Instability in the Presence of Convection |
| title_full_unstemmed | Baroclinic Instability in the Presence of Convection |
| title_short | Baroclinic Instability in the Presence of Convection |
| title_sort | baroclinic instability in the presence of convection |
| url | http://hdl.handle.net/1721.1/118435 https://orcid.org/0000-0002-3736-1956 |
| work_keys_str_mv | AT calliesjorn baroclinicinstabilityinthepresenceofconvection AT ferrariraffaele baroclinicinstabilityinthepresenceofconvection |