Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula
The structure of lee-side warming during foehn events is investigated as a function of cross-barrier flow regime linearity. Two contrasting cases of westerly flow over the Antarctic Peninsula (AP) are considered – one highly nonlinear, the other relatively linear. Westerly flow impinging on the AP p...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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ftuniveastangl:oai:ueaeprints.uea.ac.uk:52349 2023-05-15T14:08:46+02:00 Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula Elvidge, Andrew Renfrew, Ian King, John Orr, Andrew Lachlan-Cope, Tom 2016-01 application/pdf https://ueaeprints.uea.ac.uk/id/eprint/52349/ https://ueaeprints.uea.ac.uk/id/eprint/52349/1/elvidge_etal_linear_nonlinear_foehn_QJRMS_2014_qj2489.pdf https://doi.org/10.1002/qj.2489 en eng https://ueaeprints.uea.ac.uk/id/eprint/52349/1/elvidge_etal_linear_nonlinear_foehn_QJRMS_2014_qj2489.pdf Elvidge, Andrew, Renfrew, Ian, King, John, Orr, Andrew and Lachlan-Cope, Tom (2016) Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula. Quarterly Journal of the Royal Meteorological Society, 142 (695). pp. 618-631. ISSN 0035-9009 doi:10.1002/qj.2489 cc_by Article PeerReviewed 2016 ftuniveastangl https://doi.org/10.1002/qj.2489 2023-03-23T23:32:05Z The structure of lee-side warming during foehn events is investigated as a function of cross-barrier flow regime linearity. Two contrasting cases of westerly flow over the Antarctic Peninsula (AP) are considered – one highly nonlinear, the other relatively linear. Westerly flow impinging on the AP provides one of the best natural laboratories in the world for the study of foehn, owing to its maritime setting and the Larsen C Ice Shelf (LCIS) providing an expansive, homogeneous and smooth surface on its east side. Numerical simulations with the Met Office Unified Model (at 1.5 km grid size) and aircraft observations are utilized. In case A, relatively weak southwesterly cross-Peninsula flow and an elevated upwind inversion dictate a highly nonlinear foehn event, with mountain wave breaking observed. The consequent strongly accelerated downslope flow leads to high-amplitude warming and ice-shelf melt in the immediate lee of the AP. However this foehn warming diminishes rapidly downwind due to upward ascent of the foehn flow via a hydraulic jump. In case C, strong northwesterly winds dictate a relatively linear flow regime. There is no hydraulic jump and strong foehn winds are able to flow at low levels across the entire ice shelf, mechanically mixing the near-surface flow, preventing the development of a strong surface inversion and delivering large fluxes of sensible heat to the ice shelf. Consequently, in case C ice-melt rates are considerably greater over the LCIS as a whole than in case A. Our results imply that although nonlinear foehn events cause intense warming in the immediate lee of mountains, linear foehn events will commonly cause more extensive lee-side warming and, over an ice surface, higher melt rates. This has major implications for the AP, where recent east-coast warming has led to the collapse of two ice shelves immediately north of the LCIS. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Ice Shelf Ice Shelves University of East Anglia: UEA Digital Repository Antarctic Antarctic Peninsula The Antarctic Quarterly Journal of the Royal Meteorological Society 142 695 618 631 |
institution |
Open Polar |
collection |
University of East Anglia: UEA Digital Repository |
op_collection_id |
ftuniveastangl |
language |
English |
description |
The structure of lee-side warming during foehn events is investigated as a function of cross-barrier flow regime linearity. Two contrasting cases of westerly flow over the Antarctic Peninsula (AP) are considered – one highly nonlinear, the other relatively linear. Westerly flow impinging on the AP provides one of the best natural laboratories in the world for the study of foehn, owing to its maritime setting and the Larsen C Ice Shelf (LCIS) providing an expansive, homogeneous and smooth surface on its east side. Numerical simulations with the Met Office Unified Model (at 1.5 km grid size) and aircraft observations are utilized. In case A, relatively weak southwesterly cross-Peninsula flow and an elevated upwind inversion dictate a highly nonlinear foehn event, with mountain wave breaking observed. The consequent strongly accelerated downslope flow leads to high-amplitude warming and ice-shelf melt in the immediate lee of the AP. However this foehn warming diminishes rapidly downwind due to upward ascent of the foehn flow via a hydraulic jump. In case C, strong northwesterly winds dictate a relatively linear flow regime. There is no hydraulic jump and strong foehn winds are able to flow at low levels across the entire ice shelf, mechanically mixing the near-surface flow, preventing the development of a strong surface inversion and delivering large fluxes of sensible heat to the ice shelf. Consequently, in case C ice-melt rates are considerably greater over the LCIS as a whole than in case A. Our results imply that although nonlinear foehn events cause intense warming in the immediate lee of mountains, linear foehn events will commonly cause more extensive lee-side warming and, over an ice surface, higher melt rates. This has major implications for the AP, where recent east-coast warming has led to the collapse of two ice shelves immediately north of the LCIS. |
format |
Article in Journal/Newspaper |
author |
Elvidge, Andrew Renfrew, Ian King, John Orr, Andrew Lachlan-Cope, Tom |
spellingShingle |
Elvidge, Andrew Renfrew, Ian King, John Orr, Andrew Lachlan-Cope, Tom Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula |
author_facet |
Elvidge, Andrew Renfrew, Ian King, John Orr, Andrew Lachlan-Cope, Tom |
author_sort |
Elvidge, Andrew |
title |
Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula |
title_short |
Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula |
title_full |
Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula |
title_fullStr |
Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula |
title_full_unstemmed |
Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula |
title_sort |
foehn warming distributions in nonlinear and linear flow regimes: a focus on the antarctic peninsula |
publishDate |
2016 |
url |
https://ueaeprints.uea.ac.uk/id/eprint/52349/ https://ueaeprints.uea.ac.uk/id/eprint/52349/1/elvidge_etal_linear_nonlinear_foehn_QJRMS_2014_qj2489.pdf https://doi.org/10.1002/qj.2489 |
geographic |
Antarctic Antarctic Peninsula The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Ice Shelf Ice Shelves |
op_relation |
https://ueaeprints.uea.ac.uk/id/eprint/52349/1/elvidge_etal_linear_nonlinear_foehn_QJRMS_2014_qj2489.pdf Elvidge, Andrew, Renfrew, Ian, King, John, Orr, Andrew and Lachlan-Cope, Tom (2016) Foehn warming distributions in nonlinear and linear flow regimes: a focus on the Antarctic Peninsula. Quarterly Journal of the Royal Meteorological Society, 142 (695). pp. 618-631. ISSN 0035-9009 doi:10.1002/qj.2489 |
op_rights |
cc_by |
op_doi |
https://doi.org/10.1002/qj.2489 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
142 |
container_issue |
695 |
container_start_page |
618 |
op_container_end_page |
631 |
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1766280787352616960 |