Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments
The Nordic seas region, due to its unique geographical and climatological conditions, experiences a number of adverse mesoscale weather events that have proven fatal for human activities in the area. Most of these weather events occur in the winter season and include orography-induced wind extremes,...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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Language: | English |
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The University of Bergen
2011
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Online Access: | https://hdl.handle.net/1956/4870 |
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ftunivbergen:oai:bora.uib.no:1956/4870 2023-05-15T16:34:38+02:00 Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments Adakudlu, Muralidhar 2011-06-22 application/pdf https://hdl.handle.net/1956/4870 eng eng The University of Bergen Paper I: Idar Barstad and Muralidhar Adakudlu. 2011. Observation and modelling of gap flow and wake formation on Svalbard. Accepted version. Quarterly Journal of Royal Meteorological Society. Copyright 2011 Royal Meteorological Society. Published by John Wiley & Sons. All Rights Reserved. The published version is available at: http://dx.doi.org/10.1002/qj.782 Paper II: Muralidhar Adakudlu and Idar Barstad. 2011. Impacts of the ice-cover and seasurface temperature on a polar low over the Nordic Seas: A numerical case study. Quarterly Journal of Royal Meteorological Society. Accepted version. Copyright 2011 Royal Meteorological Society. Published by John Wiley & Sons. All Rights Reserved. The published version is available at: http://dx.doi.org/10.1002/qj.856 Paper III: Muralidhar Adakudlu. 2011. Impacts of different initial conditions on the growth of polar lows: Idealised baroclinic channel experiments. In review. Quarterly Journal of Royal Meteorological Society.Copyright 2011 Royal Meteorological Society. All rights reserved. urn:isbn:978-82-308-1795-7 (print version) https://hdl.handle.net/1956/4870 The author Copyright the author. All rights reserved VDP::Mathematics and natural science: 400::Geosciences: 450::Meteorology: 453 Doctoral thesis 2011 ftunivbergen 2023-03-14T17:41:34Z The Nordic seas region, due to its unique geographical and climatological conditions, experiences a number of adverse mesoscale weather events that have proven fatal for human activities in the area. Most of these weather events occur in the winter season and include orography-induced wind extremes, shallow and sharp fronts that often form in the vicinity of the ice edge and intense storms called polar lows. In order to assess such high impact weather conditions, a field campaign was conducted over the Nordic seas in February-March 2008 as part of the IPY-THORPEX project. During this field campaign, measurements of a number of severe weather cases were collected through the dropsonde and lidar sensors on-board the DLR-FALCON aircraft. This thesis deals with high resolution modeling experiments of some of the cases observed during the IPY-THORPEX field campaign, with focus on the sensitivity of these events to underlying surface conditions and several physical factors. The results of these experiments are presented in the form of three scientific articles. Paper-I presents the airborne measurements of a case with strong gap winds observed at the exit region of the Hinlopen Strait in Svalbard archipelago. The DLRFALCON aircraft flew along the Hinlopen strait and recorded winds of strength ~ 20 ms−1, which was about four times higher than the upstream wind, near to the surface. In addition, formation of a wake with return currents in the lee of the terrain was also recorded by the lidar sensors carried by the aircraft. This case was simulated in a fineresolution numerical model with a high degree of accuracy. The simulations showed the existence of small-scale cloud banners extending downstream of the lee of the mountains. The causal mechanisms for such cloud features were investigated through an idealised approach. The ideal experiments indicated that the vertical circulations set up by the terrain features cause the cloud banners and a relatively warm ocean surface maintains them by supplying moisture and ... Doctoral or Postdoctoral Thesis Hinlopen Strait IPY Nordic Seas Svalbard University of Bergen: Bergen Open Research Archive (BORA-UiB) Svalbard Svalbard Archipelago Quarterly Journal of the Royal Meteorological Society 137 660 1731 1738 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
VDP::Mathematics and natural science: 400::Geosciences: 450::Meteorology: 453 |
spellingShingle |
VDP::Mathematics and natural science: 400::Geosciences: 450::Meteorology: 453 Adakudlu, Muralidhar Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments |
topic_facet |
VDP::Mathematics and natural science: 400::Geosciences: 450::Meteorology: 453 |
description |
The Nordic seas region, due to its unique geographical and climatological conditions, experiences a number of adverse mesoscale weather events that have proven fatal for human activities in the area. Most of these weather events occur in the winter season and include orography-induced wind extremes, shallow and sharp fronts that often form in the vicinity of the ice edge and intense storms called polar lows. In order to assess such high impact weather conditions, a field campaign was conducted over the Nordic seas in February-March 2008 as part of the IPY-THORPEX project. During this field campaign, measurements of a number of severe weather cases were collected through the dropsonde and lidar sensors on-board the DLR-FALCON aircraft. This thesis deals with high resolution modeling experiments of some of the cases observed during the IPY-THORPEX field campaign, with focus on the sensitivity of these events to underlying surface conditions and several physical factors. The results of these experiments are presented in the form of three scientific articles. Paper-I presents the airborne measurements of a case with strong gap winds observed at the exit region of the Hinlopen Strait in Svalbard archipelago. The DLRFALCON aircraft flew along the Hinlopen strait and recorded winds of strength ~ 20 ms−1, which was about four times higher than the upstream wind, near to the surface. In addition, formation of a wake with return currents in the lee of the terrain was also recorded by the lidar sensors carried by the aircraft. This case was simulated in a fineresolution numerical model with a high degree of accuracy. The simulations showed the existence of small-scale cloud banners extending downstream of the lee of the mountains. The causal mechanisms for such cloud features were investigated through an idealised approach. The ideal experiments indicated that the vertical circulations set up by the terrain features cause the cloud banners and a relatively warm ocean surface maintains them by supplying moisture and ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Adakudlu, Muralidhar |
author_facet |
Adakudlu, Muralidhar |
author_sort |
Adakudlu, Muralidhar |
title |
Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments |
title_short |
Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments |
title_full |
Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments |
title_fullStr |
Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments |
title_full_unstemmed |
Severe mesoscale weather events over the Nordic Seas: Numerical modelling and sensitivity experiments |
title_sort |
severe mesoscale weather events over the nordic seas: numerical modelling and sensitivity experiments |
publisher |
The University of Bergen |
publishDate |
2011 |
url |
https://hdl.handle.net/1956/4870 |
geographic |
Svalbard Svalbard Archipelago |
geographic_facet |
Svalbard Svalbard Archipelago |
genre |
Hinlopen Strait IPY Nordic Seas Svalbard |
genre_facet |
Hinlopen Strait IPY Nordic Seas Svalbard |
op_relation |
Paper I: Idar Barstad and Muralidhar Adakudlu. 2011. Observation and modelling of gap flow and wake formation on Svalbard. Accepted version. Quarterly Journal of Royal Meteorological Society. Copyright 2011 Royal Meteorological Society. Published by John Wiley & Sons. All Rights Reserved. The published version is available at: http://dx.doi.org/10.1002/qj.782 Paper II: Muralidhar Adakudlu and Idar Barstad. 2011. Impacts of the ice-cover and seasurface temperature on a polar low over the Nordic Seas: A numerical case study. Quarterly Journal of Royal Meteorological Society. Accepted version. Copyright 2011 Royal Meteorological Society. Published by John Wiley & Sons. All Rights Reserved. The published version is available at: http://dx.doi.org/10.1002/qj.856 Paper III: Muralidhar Adakudlu. 2011. Impacts of different initial conditions on the growth of polar lows: Idealised baroclinic channel experiments. In review. Quarterly Journal of Royal Meteorological Society.Copyright 2011 Royal Meteorological Society. All rights reserved. urn:isbn:978-82-308-1795-7 (print version) https://hdl.handle.net/1956/4870 |
op_rights |
The author Copyright the author. All rights reserved |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
137 |
container_issue |
660 |
container_start_page |
1731 |
op_container_end_page |
1738 |
_version_ |
1766024603334868992 |