DATE2019-01-08 12:44:23
IDABSTRACT2014/312
CONTACTdbarriop@fis.ucm.es
PRESENTATIONORAL
INVITED0
IDSESSION3
TITLEREVISITING BLOCKING DEFINITION AND ASSOCIATED IMPACTS
AUTHORSDavid / Barriopedro (1,2)
AFFILIATIONS
  1. Universidad Complutense de Madrid, Madrid, Spain
  2. Instituto de Geociencias (IGEO), CSIC-UCM, Madrid, Spain
ABSTRACTAtmospheric blockings are an important component of the intraseasonal variability in the Northern Hemisphere. Blocking is often referred to as persistent and quasi-stationary large-scale anticyclonic systems in the mid and high latitudes although there is a lack of agreement on defining blocking. They are characterized by a strong meridional circulation and a perturbed jet stream, thus disrupting the regular eastward progression of mid-latitude disturbances. As a consequence, blocking episodes are associated with anomalous weather conditions over long periods and large areas of mid and high latitudes, including the Mediterranean region. On the other hand, blocks represent a challenge for General Circulation Models (GCMs) and hence, the behavior of blocking in future climate is still unclear. An updated review of different aspects of blocking is herein presented based on some published studies. They include an assessment of the performance of different blocking detection indices and some of their discrepancies and implications. The impacts in temperature and precipitation associated with regional blocking events over the Euro-Atlantic sector are also described, including the role played by anomalous blocking activity in recent mega-heatwave episodes. Finally, some sources of uncertainty in the representation and future projections of blocking by state-of-the-art GCMs are also briefly discussed.
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