Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study
We investigate an intense snowfall event between 15 and 18 February 2011 over the East Antarctic coastal region which contributed to roughly 24% of the annual snow accumulation. The event was previously associated with an atmospheric river, and here we use both Eulerian and Lagrangian analysis to ga...
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ftunivbergen:oai:bora.uib.no:11250/2988641 2023-05-15T14:07:50+02:00 Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study Terpstra, Annick Gorodetskaya, Irina V. Sodemann, Harald 2021 application/pdf https://hdl.handle.net/11250/2988641 https://doi.org/10.1029/2020JD033617 eng eng Wiley Norges forskningsråd: 262710 urn:issn:2169-897X https://hdl.handle.net/11250/2988641 https://doi.org/10.1029/2020JD033617 cristin:1984044 Journal of Geophysical Research: Atmospheres. 2021, 126 (9), e2020JD033617. Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright 2021. The Authors e2020JD033617 Journal of Geophysical Research (JGR): Atmospheres 126 9 Journal article Peer reviewed 2021 ftunivbergen https://doi.org/10.1029/2020JD033617 2023-03-14T17:42:24Z We investigate an intense snowfall event between 15 and 18 February 2011 over the East Antarctic coastal region which contributed to roughly 24% of the annual snow accumulation. The event was previously associated with an atmospheric river, and here we use both Eulerian and Lagrangian analysis to gain an understanding of the processes contributing to the atmospheric river signature. The planetary-scale configuration during the event consisted of a persistent blocking situation resulting in a sustained meridional flow from the sub-tropics to the Antarctic ice sheet between 20 and 50°E. Within this configuration, synoptic-scale cyclogenesis contributed to slantwise ascent of moisture loaded air parcels toward Antarctica. Landfall of this cyclone’s warm sector coincided with the onset of Antarctic precipitation. Subsequently, a secondary cyclone developed along a pre-existing baroclinic zone. The rapid intensification and propagation speed of this mesoscale cyclone alongside the warm, moist air mass resulted in strong moisture flux convergence ahead of the cyclone, providing additional poleward moisture transport. The poleward progression of warm moist air and a corresponding decrease of sea-surface temperatures implied downward surface sensible and latent heat fluxes throughout the region of intense poleward moisture, roughly between 40 and 60°S. Hence, moisture uptake via surface evaporation was suppressed between the sub-tropics and the polar continent, favoring long-range transport. Identification of the surface moisture uptake region by tracing changes in moisture in air parcels confirmed the limited uptake of moisture during the poleward transport in this case study, with the primary moisture source for Antarctic precipitation located in the sub-tropics. publishedVersion Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet University of Bergen: Bergen Open Research Archive (BORA-UiB) Antarctic East Antarctica The Antarctic Journal of Geophysical Research: Atmospheres 126 9 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
We investigate an intense snowfall event between 15 and 18 February 2011 over the East Antarctic coastal region which contributed to roughly 24% of the annual snow accumulation. The event was previously associated with an atmospheric river, and here we use both Eulerian and Lagrangian analysis to gain an understanding of the processes contributing to the atmospheric river signature. The planetary-scale configuration during the event consisted of a persistent blocking situation resulting in a sustained meridional flow from the sub-tropics to the Antarctic ice sheet between 20 and 50°E. Within this configuration, synoptic-scale cyclogenesis contributed to slantwise ascent of moisture loaded air parcels toward Antarctica. Landfall of this cyclone’s warm sector coincided with the onset of Antarctic precipitation. Subsequently, a secondary cyclone developed along a pre-existing baroclinic zone. The rapid intensification and propagation speed of this mesoscale cyclone alongside the warm, moist air mass resulted in strong moisture flux convergence ahead of the cyclone, providing additional poleward moisture transport. The poleward progression of warm moist air and a corresponding decrease of sea-surface temperatures implied downward surface sensible and latent heat fluxes throughout the region of intense poleward moisture, roughly between 40 and 60°S. Hence, moisture uptake via surface evaporation was suppressed between the sub-tropics and the polar continent, favoring long-range transport. Identification of the surface moisture uptake region by tracing changes in moisture in air parcels confirmed the limited uptake of moisture during the poleward transport in this case study, with the primary moisture source for Antarctic precipitation located in the sub-tropics. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Terpstra, Annick Gorodetskaya, Irina V. Sodemann, Harald |
spellingShingle |
Terpstra, Annick Gorodetskaya, Irina V. Sodemann, Harald Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study |
author_facet |
Terpstra, Annick Gorodetskaya, Irina V. Sodemann, Harald |
author_sort |
Terpstra, Annick |
title |
Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study |
title_short |
Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study |
title_full |
Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study |
title_fullStr |
Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study |
title_full_unstemmed |
Linking Sub-Tropical Evaporation and Extreme Precipitation Over East Antarctica: An Atmospheric River Case Study |
title_sort |
linking sub-tropical evaporation and extreme precipitation over east antarctica: an atmospheric river case study |
publisher |
Wiley |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/2988641 https://doi.org/10.1029/2020JD033617 |
geographic |
Antarctic East Antarctica The Antarctic |
geographic_facet |
Antarctic East Antarctica The Antarctic |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet |
op_source |
e2020JD033617 Journal of Geophysical Research (JGR): Atmospheres 126 9 |
op_relation |
Norges forskningsråd: 262710 urn:issn:2169-897X https://hdl.handle.net/11250/2988641 https://doi.org/10.1029/2020JD033617 cristin:1984044 Journal of Geophysical Research: Atmospheres. 2021, 126 (9), e2020JD033617. |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright 2021. The Authors |
op_doi |
https://doi.org/10.1029/2020JD033617 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
126 |
container_issue |
9 |
_version_ |
1766279871335497728 |