Accessibility navigation

Transient anticyclonic eddies and their relationship to atmospheric block persistence

Suitters, C. C., Martinez-Alvarado, O., Hodges, K. I., Schiemann, R. K. H. and Ackerley, D. (2023) Transient anticyclonic eddies and their relationship to atmospheric block persistence. Weather and Climate Dynamics. ISSN 2698-4016 (In Press)

[img] Text - Accepted Version
· Restricted to Repository staff only
· The Copyright of this document has not been checked yet. This may affect its availability.


It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.


Atmospheric blocking is a circulation pattern that describes the presence of large-scale, persistent anticyclones, which have the potential to bring severe impacts at the surface. However, the dynamical behaviour of blocks is still not fully understood. For example, the factors that determine the persistence of blocking events are not clear. In this study, the relationship between blocks and smaller-scale transient anticyclonic eddies is examined, with a particular focus on the impact of transients on the persistence of a block. Analysis is performed in two areas: the Euro-Atlantic and North Pacific, which are locations with both high blocking frequency and potential for severe impacts. Geopotential height anomalies at 500 hPa are used to identify blocking events and the anticyclonic transient eddies. This allows for a Eulerian definition of blocking, as well as a Lagrangian perspective on the eddies. It is found that anticyclonic eddies experience a northward acceleration prior to entering a block, which is indicative of ridge-building ahead of a block, but could also potentially provide evidence for the previously-proposed Selective Absorption Mechanism for block maintenance. A general pattern is found whereby longer blocks interact with more anticyclonic transients than less persistent blocks at all times of year. This effect is strongest in winter and weakest in summer, which agrees with the fact that blocks are most persistent in winter and least persistent in summer. However, the strength of the anticyclonic eddy, measured by its maximum 500 hPa geopotential height anomaly, that interacts with a block generally has very little bearing on the persistence of a block, aside from a few cases.

Item Type:Article
Divisions:Science > School of Mathematical, Physical and Computational Sciences > NCAS
Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
ID Code:112701
Publisher:European Geosciences Union

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation