Representation of Extratropical Cyclones, Blocking Anticyclones, and Alpine Circulation Types in Multiple Reanalyses and Model Simulations

Rohrer, Marco; Brönnimann, Stefan; Martius, Olivia; Raible, Christoph; Wild, Martin; Compo, Gilbert P. (2018). Representation of Extratropical Cyclones, Blocking Anticyclones, and Alpine Circulation Types in Multiple Reanalyses and Model Simulations. Journal of Climate, 31(8), pp. 3009-3031. American Meteorological Society 10.1175/JCLI-D-17-0350.1

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Atmospheric circulation types, blockings, and cyclones are central features of the extratropical flow and key to understanding the climate system. This study intercompares the representation of these features in 10 reanalyses and in an ensemble of 30 climate model simulations between 1980 and 2005. Both modern, full-input reanalyses and century-long, surface-input reanalyses are examined. Modern full-input reanalyses agree well on key statistics of blockings, cyclones, and circulation types. However, the intensity and depth of cyclones vary among them. Reanalyses with higher horizontal resolution show higher cyclone center densities and more intense cyclones. For blockings, no strict relationship is found between frequency or intensity and horizontal resolution. Full-input reanalyses contain more intense blocking, compared to surface-input reanalyses. Circulation-type classifications over central Europe show that both versions of the Twentieth Century Reanalysis dataset contain more easterlies and fewer westerlies than any other reanalysis, owing to their high pressure bias over northeast Europe. The temporal correlation of annual circulation types over central Europe and blocking frequencies over the North Atlantic–European domain between reanalyses is high (around 0.8). The ensemble simulations capture the main characteristics of midlatitudinal atmospheric circulation. Circulation types of westerlies to northerlies over central Europe are overrepresented. There are too few blockings in the higher latitudes and an excess of cyclones in the midlatitudes. Other characteristics, such as blocking amplitude and cyclone intensity, are realistically represented, making the ensemble simulations a rich dataset to assess changes in climate variability.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Physics Institute > Climate and Environmental Physics
08 Faculty of Science > Institute of Geography
08 Faculty of Science > Institute of Geography > Physical Geography

Graduate School:

Graduate School of Climate Sciences

UniBE Contributor:

Rohrer, Marco; Brönnimann, Stefan; Romppainen-Martius, Olivia and Raible, Christoph

Subjects:

500 Science > 530 Physics
500 Science > 550 Earth sciences & geology
900 History > 910 Geography & travel

ISSN:

0894-8755

Publisher:

American Meteorological Society

Projects:

[245] Mobiliar Lab für Naturrisiken Official URL

Language:

English

Submitter:

Monika Wälti-Stampfli

Date Deposited:

08 May 2018 12:59

Last Modified:

22 Mar 2019 08:59

Publisher DOI:

10.1175/JCLI-D-17-0350.1

BORIS DOI:

10.7892/boris.116228

URI:

https://boris.unibe.ch/id/eprint/116228

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