The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions
The effect of sea-ice on various aspects of the Southern Hemisphere (SH) extratropical climate is examined. Two simulations using the LMD GCM are performed: a control run with the observed sea-ice distribution and an anomaly run in which all SH sea-ice is replaced by open ocean. When sea-ice is...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
1999-11-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/17/1478/1999/angeo-17-1478-1999.pdf |
| _version_ | 1818007498937860096 |
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| author | C. G. Menéndez V. Serafini H. Le Treut |
| author_facet | C. G. Menéndez V. Serafini H. Le Treut |
| author_sort | C. G. Menéndez |
| collection | DOAJ |
| description | The effect of sea-ice on various aspects of
the Southern Hemisphere (SH) extratropical climate is examined. Two simulations
using the LMD GCM are performed: a control run with the observed sea-ice
distribution and an anomaly run in which all SH sea-ice is replaced by open
ocean. When sea-ice is removed, the mean sea level pressure displays anomalies
predominantly negatives near the Antarctic coast. In general, the meridional
temperature gradient is reduced over most of the Southern Ocean, the polar jet
is weaker and the sea level pressure rises equatorward of the control ice edge.
The high frequency filtered standard deviation of both the sea level pressure
and the 300-hPa geopotential height decreases over the southern Pacific and
southwestern Atlantic oceans, especially to the north of the ice edge (as
prescribed in the control). In contrast, over the Indian Ocean the perturbed
simulation exhibits less variability equatorward of about 50°S and increased
variability to the south. The zonal averages of the zonal and eddy potential and
kinetic energies were evaluated. The effect of removing sea-ice is to diminish
the available potential energy of the mean zonal flow, the available potential
energy of the perturbations, the kinetic energy of the growing disturbances and
the kinetic energy of the mean zonal flow over most of the Southern Ocean. The
zonally averaged intensity of the subpolar trough and the rate of the baroclinic
energy conversions are also weaker.<br><br><b>Key words. </b>Air-sea interactions · Meteorology and
atmospheric dynamics (climatology; ocean · atmosphere interactions) |
| first_indexed | 2024-04-14T05:17:21Z |
| format | Article |
| id | doaj.art-36b1d31ca5d04aae9e4cd829aefe653c |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-14T05:17:21Z |
| publishDate | 1999-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-36b1d31ca5d04aae9e4cd829aefe653c2022-12-22T02:10:20ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05761999-11-01171478149210.1007/s00585-999-1478-2The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditionsC. G. Menéndez0V. Serafini1H. Le Treut2Centro de Investigaciones del Mar y la Atmósfera/CONICET-UBA, Ciudad Universitaria, Pabellón 2, Piso 2, (1428) Buenos Aires, ArgentinaLaboratoire de Météorologie Dynamique/CNRS, Université P. et M. Curie, Tour 15-25, 4 place Jussieu, 75252 Paris Cedex 05, FranceLaboratoire de Météorologie Dynamique/CNRS, Université P. et M. Curie, Tour 15-25, 4 place Jussieu, 75252 Paris Cedex 05, FranceThe effect of sea-ice on various aspects of the Southern Hemisphere (SH) extratropical climate is examined. Two simulations using the LMD GCM are performed: a control run with the observed sea-ice distribution and an anomaly run in which all SH sea-ice is replaced by open ocean. When sea-ice is removed, the mean sea level pressure displays anomalies predominantly negatives near the Antarctic coast. In general, the meridional temperature gradient is reduced over most of the Southern Ocean, the polar jet is weaker and the sea level pressure rises equatorward of the control ice edge. The high frequency filtered standard deviation of both the sea level pressure and the 300-hPa geopotential height decreases over the southern Pacific and southwestern Atlantic oceans, especially to the north of the ice edge (as prescribed in the control). In contrast, over the Indian Ocean the perturbed simulation exhibits less variability equatorward of about 50°S and increased variability to the south. The zonal averages of the zonal and eddy potential and kinetic energies were evaluated. The effect of removing sea-ice is to diminish the available potential energy of the mean zonal flow, the available potential energy of the perturbations, the kinetic energy of the growing disturbances and the kinetic energy of the mean zonal flow over most of the Southern Ocean. The zonally averaged intensity of the subpolar trough and the rate of the baroclinic energy conversions are also weaker.<br><br><b>Key words. </b>Air-sea interactions · Meteorology and atmospheric dynamics (climatology; ocean · atmosphere interactions)https://www.ann-geophys.net/17/1478/1999/angeo-17-1478-1999.pdf |
| spellingShingle | C. G. Menéndez V. Serafini H. Le Treut The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions Annales Geophysicae |
| title | The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions |
| title_full | The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions |
| title_fullStr | The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions |
| title_full_unstemmed | The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions |
| title_short | The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions |
| title_sort | storm tracks and the energy cycle of the southern hemisphere sensitivity to sea ice boundary conditions |
| url | https://www.ann-geophys.net/17/1478/1999/angeo-17-1478-1999.pdf |
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