Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19
We calculate a regional surface “melt potential” index (MPI) over Antarctic ice shelves that describes the frequency (MPI-freq, %) and intensity (MPI-int, K) of daily maximum summer temperatures exceeding a melt threshold of 273.15 K. This is used to determine which ice shelves are vulnerable to mel...
Published in: | Journal of Climate |
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Main Authors: | , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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American Meteorological Society
2023
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Online Access: | http://nora.nerc.ac.uk/id/eprint/534182/ https://nora.nerc.ac.uk/id/eprint/534182/1/1520-0442-JCLI-D-22-0386.1.pdf https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-22-0386.1/JCLI-D-22-0386.1.xml |
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ftnerc:oai:nora.nerc.ac.uk:534182 2023-06-11T04:04:24+02:00 Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van de Berg, Willem Jan Webster, Stuart Zou, Xun 2023-05-15 text http://nora.nerc.ac.uk/id/eprint/534182/ https://nora.nerc.ac.uk/id/eprint/534182/1/1520-0442-JCLI-D-22-0386.1.pdf https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-22-0386.1/JCLI-D-22-0386.1.xml en eng American Meteorological Society https://nora.nerc.ac.uk/id/eprint/534182/1/1520-0442-JCLI-D-22-0386.1.pdf Orr, Andrew orcid:0000-0001-5111-8402 Deb, Pranab; Clem, Kyle R.; Gilbert, Ella orcid:0000-0001-5272-8894 Bromwich, David H.; Boberg, Fredrik; Colwell, Steve; Hansen, Nicolaj; Lazzara, Matthew A.; Mooney, Priscilla A.; Mottram, Ruth; Niwano, Masashi; Phillips, Tony orcid:0000-0002-3058-9157 Pishniak, Denys; Reijmer, Carleen H.; van de Berg, Willem Jan; Webster, Stuart; Zou, Xun. 2023 Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19. Journal of Climate, 36 (10). 3357-3383. https://doi.org/10.1175/JCLI-D-22-0386.1 <https://doi.org/10.1175/JCLI-D-22-0386.1> cc_by_4 Publication - Article PeerReviewed 2023 ftnerc https://doi.org/10.1175/JCLI-D-22-0386.1 2023-05-04T23:02:43Z We calculate a regional surface “melt potential” index (MPI) over Antarctic ice shelves that describes the frequency (MPI-freq, %) and intensity (MPI-int, K) of daily maximum summer temperatures exceeding a melt threshold of 273.15 K. This is used to determine which ice shelves are vulnerable to melt-induced hydrofracture and is calculated using near-surface temperature output for each summer from 1979/80 to 2018/19 from two high-resolution regional atmospheric model hindcasts (using the MetUM and HIRHAM5). MPI is highest for Antarctic Peninsula ice shelves (MPI-freq 23-35%, MPI-int 1.2-2.1 K), lowest (2-3%, < 0 K) for Ronne-Filchner and Ross ice shelves, and around 10-24% and 0.6-1.7 K for the other West and East Antarctic ice shelves. Hotspots of MPI are apparent over many ice shelves, and they also show a decreasing trend in MPI-freq. The regional circulation patterns associated with high MPI values over West and East Antarctic ice shelves are remarkably consistent for their respective region but tied to different large-scale climate forcings. The West Antarctic circulation resembles the central Pacific El Niño pattern with a stationary Rossby wave and a strong anticyclone over the high-latitude South Pacific. By contrast, the East Antarctic circulation comprises a zonally symmetric negative Southern Annular Mode pattern with a strong regional anticyclone on the plateau and enhanced coastal easterlies/weakened Southern Ocean westerlies. Values of MPI are 3-4 times larger for a lower temperature/melt threshold of 271.15 K used in a sensitivity test, as melting can occur at temperatures lower than 273.15 K depending on snowpack properties. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Ice Shelves Southern Ocean Natural Environment Research Council: NERC Open Research Archive Antarctic Antarctic Peninsula Pacific Southern Ocean Journal of Climate 1 61 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
We calculate a regional surface “melt potential” index (MPI) over Antarctic ice shelves that describes the frequency (MPI-freq, %) and intensity (MPI-int, K) of daily maximum summer temperatures exceeding a melt threshold of 273.15 K. This is used to determine which ice shelves are vulnerable to melt-induced hydrofracture and is calculated using near-surface temperature output for each summer from 1979/80 to 2018/19 from two high-resolution regional atmospheric model hindcasts (using the MetUM and HIRHAM5). MPI is highest for Antarctic Peninsula ice shelves (MPI-freq 23-35%, MPI-int 1.2-2.1 K), lowest (2-3%, < 0 K) for Ronne-Filchner and Ross ice shelves, and around 10-24% and 0.6-1.7 K for the other West and East Antarctic ice shelves. Hotspots of MPI are apparent over many ice shelves, and they also show a decreasing trend in MPI-freq. The regional circulation patterns associated with high MPI values over West and East Antarctic ice shelves are remarkably consistent for their respective region but tied to different large-scale climate forcings. The West Antarctic circulation resembles the central Pacific El Niño pattern with a stationary Rossby wave and a strong anticyclone over the high-latitude South Pacific. By contrast, the East Antarctic circulation comprises a zonally symmetric negative Southern Annular Mode pattern with a strong regional anticyclone on the plateau and enhanced coastal easterlies/weakened Southern Ocean westerlies. Values of MPI are 3-4 times larger for a lower temperature/melt threshold of 271.15 K used in a sensitivity test, as melting can occur at temperatures lower than 273.15 K depending on snowpack properties. |
format |
Article in Journal/Newspaper |
author |
Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van de Berg, Willem Jan Webster, Stuart Zou, Xun |
spellingShingle |
Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van de Berg, Willem Jan Webster, Stuart Zou, Xun Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
author_facet |
Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van de Berg, Willem Jan Webster, Stuart Zou, Xun |
author_sort |
Orr, Andrew |
title |
Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
title_short |
Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
title_full |
Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
title_fullStr |
Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
title_full_unstemmed |
Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
title_sort |
characteristics of surface “melt potential” over antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
publisher |
American Meteorological Society |
publishDate |
2023 |
url |
http://nora.nerc.ac.uk/id/eprint/534182/ https://nora.nerc.ac.uk/id/eprint/534182/1/1520-0442-JCLI-D-22-0386.1.pdf https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-22-0386.1/JCLI-D-22-0386.1.xml |
geographic |
Antarctic Antarctic Peninsula Pacific Southern Ocean |
geographic_facet |
Antarctic Antarctic Peninsula Pacific Southern Ocean |
genre |
Antarc* Antarctic Antarctic Peninsula Ice Shelves Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Ice Shelves Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/534182/1/1520-0442-JCLI-D-22-0386.1.pdf Orr, Andrew orcid:0000-0001-5111-8402 Deb, Pranab; Clem, Kyle R.; Gilbert, Ella orcid:0000-0001-5272-8894 Bromwich, David H.; Boberg, Fredrik; Colwell, Steve; Hansen, Nicolaj; Lazzara, Matthew A.; Mooney, Priscilla A.; Mottram, Ruth; Niwano, Masashi; Phillips, Tony orcid:0000-0002-3058-9157 Pishniak, Denys; Reijmer, Carleen H.; van de Berg, Willem Jan; Webster, Stuart; Zou, Xun. 2023 Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19. Journal of Climate, 36 (10). 3357-3383. https://doi.org/10.1175/JCLI-D-22-0386.1 <https://doi.org/10.1175/JCLI-D-22-0386.1> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1175/JCLI-D-22-0386.1 |
container_title |
Journal of Climate |
container_start_page |
1 |
op_container_end_page |
61 |
_version_ |
1768387638840000512 |