Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rossby wave breaking and extreme windstorms overWestern Europe
Stockholm University, Faculty of Science, Department of Meteorology .
Stockholm University, Faculty of Science, Department of Meteorology .
(English)Manuscript (preprint) (Other academic)
Abstract [en]

We investigate the role of upper-level Rossby wave breaking in the evolution ofthemost extreme windstorms affecting three regions inWestern Europe: Britainand Ireland, Scandinavia and Western Continental Europe. Using ERA40and ERA-Interim reanalysis data along with EC-Earth model output at twodifferent spatial resolutions, we first construct an extreme wind climatologyover the selected regions and inter-compare the model climatology with thatcomputed from the reanalysis data. Using a storm destructiveness measure, wethen select the top 25 most destructive storms in each region from a multidecadalclimatology in each of our four datasets; track-by-track analysis revealsa good agreement in the trajectories and evolution of these storms in bothmodel resolutions compared to the reanalysis data. Temporal MSLP reanalysiscomposites demonstrate that in each region, there exists a set of large-scaleconditions conducive to the development of these storms; similar composites ofmodel output data show that these surface conditions are broadly well capturedby both model resolutions. Temporal composites of potential temperature onthe 2-PVU surface using reanalysis data reveal that these regional large-scalesurface patterns can be associated with exceptional cyclonic and anti-cyclonicwave breaking occurring contemporaneously in the North Atlantic; the preciselocation of these wave breaking events controls the position and orientation ofan intense upper-level jet which in turn determines into which region the stormsare steered. Similar composites using model output data show qualitativelythe same picture, but with an overall positive bias most likely due to a lowertropopause height in the model.

Keyword [en]
Rossby wave breaking, Extreme windstorms, Western Europe
National Category
Meteorology and Atmospheric Sciences
Research subject
Atmospheric Sciences and Oceanography
Identifiers
URN: urn:nbn:se:su:diva-86519OAI: oai:DiVA.org:su-86519DiVA: diva2:587162
Available from: 2013-01-14 Created: 2013-01-14 Last updated: 2013-01-14
In thesis
1. Extreme Storms in the North Atlantic and Europe
Open this publication in new window or tab >>Extreme Storms in the North Atlantic and Europe
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A study of the most extreme cyclones affecting the North Atlantic and Europe is presented with particular focus on extreme windstorms over the densely populated area of Western Europe, whose associated high surface wind speeds are capable of causing extensive structural damage and occasionally a loss of life.

A novel cyclone identification and tracking algorithm is presented which explicitly recognises ‘multi-centre cyclones’ (MCCs), defined as cyclonic systems which contain two or three sea-level pressure minima. The method also recognises cyclone merging and splitting events and reduces the number of tracks which would have been spuriously split at some point in their life-cycle. MCC frequency is shown to increase with storm intensity, with approximately 60% of the top 30% of cyclones constituting MCCs at some point in their life-cycle.

The first findings of the IMILAST (Inter-comparison of MId-LAtitudeSTorm diagnostics) project, an intercomparison study of 15 cyclone identification and tracking algorithms, are presented. Each method was applied to a 20 year period of the ERA-Interim dataset and results for cyclone frequency, intensity, life-cycle and track location were compared across the methods.

The relationship between the evolution of the most intense wind storms affecting Western Europe (Britain and Ireland, Scandinavia, and Western Continental Europe) and the large-scale atmospheric flow is investigated using an automated cyclone tracking algorithm and an objective measure of cyclone destructiveness applied to ERA40 and ERA-Interim reanalysis data as well as EC-Earth model output data at two different spatial resolutions. Composite analyses reveal a clear connection between the precise location of upper-level anti-cyclonic wave breaking and cold air intrusion from the north and the position and orientation of an intense jet; this, in turn, plays a crucial role in determining into which region a developing extreme storm will be steered.

Place, publisher, year, edition, pages
Stockholm: Department of Meteorology, Stockholm University, 2013. 44 p.
National Category
Meteorology and Atmospheric Sciences
Research subject
Atmospheric Sciences and Oceanography
Identifiers
urn:nbn:se:su:diva-86533 (URN)978-91-7447-630-9 (ISBN)
Public defence
2013-02-05, Nordenskiöldsalen, Geovetenskapens hus, Svante Arrhenius väg 12, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Epub ahead of print. Paper 4: Manuscript.

 

Available from: 2013-01-15 Created: 2013-01-14 Last updated: 2013-06-12Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Hanley, JohnCaballero, Rodrigo
By organisation
Department of Meteorology
Meteorology and Atmospheric Sciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 72 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf