On the dynamics of blocking systems affecting Europe

Postgraduate Thesis uoadl:2943645 168 Read counter

Unit:
Κατεύθυνση Φυσική Περιβάλλοντος
Library of the School of Science
Deposit date:
2021-04-20
Year:
2021
Author:
Toumpos Michail
Supervisors info:
Φλόκα Έλενα, Καθηγήτρια, Τμήμα Φυσικής, ΕΚΠΑ
Χατζάκη Μαρία, Επίκουρη Καθηγήτρια, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Ντάντου Αγγελική, Ε.ΔΙ.Π, Τμήμα Φυσικής, ΕΚΠΑ
Original Title:
On the dynamics of blocking systems affecting Europe
Languages:
English
Translated title:
On the dynamics of blocking systems affecting Europe
Summary:
Atmospheric blocking is a one of the important aspects of weather in middle latitudes. It is a large-scale quasi-stationary extratropical flow regime and its onset is accompanied by a sudden breakdown of the mid-latitude westerly flow with the ambient westerly winds being replaced by easterlies. Blocking episodes can be associated with extreme weather such as droughts in summer and severe cold spells in winter. Despite the importance of blocking, its dynamics of initiation and maintenance is not well understood.
The basis of this study is a detailed analysis of climatology of blocking on the Euro-Atlantic domain, with the aid of a dynamically based blocking index and the new ERA-5 data set.
The blocking index is characterized by a very high day-to-day variability, especially in the vicinity of the Atlantic. The area of central Europe is the region where blocking is more frequent whereas the Atlantic storm tracks have a significant influence on the seasonal variability of blocking. In the areas where blocking is more often, the events last longer. The study of characteristic timescale shows that the persistence of the sector blocking episodes is increased compared to short-lived. The strength of blocking is independent from the region and the blocking frequency. Finally, as far for the evolution of strength of SBEs, there is no evidence that a typical strength life-cycle exists.
Main subject category:
Science
Keywords:
Blocking, jet-stream, potential temperature, blocking index, synoptic activity
Index:
Yes
Number of index pages:
2
Contains images:
Yes
Number of references:
140
Number of pages:
111
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