Open AccessThe unusual Buenos Aires snowfall of July 2007
Author(s) -
Pezza Alexandre Bernardes,
Simmonds Ian,
Coelho Caio A. S.
Publication year - 2010
Publication title -
atmospheric science letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.951
H-Index - 45
ISSN - 1530-261X
DOI - 10.1002/asl.283
Subject(s) - climatology , peninsula , snow , latitude , winter storm , middle latitudes , geography , circumpolar star , advection , high latitude , oceanography , geology , meteorology , archaeology , physics , geodesy , thermodynamics
Buenos Aires lies near the east coast of South America at about 34°S where snow is extremely rare. The only events measured in the city had occurred before 1930. The high latitude causes of the widespread snowstorm of 9th July 2007 are discussed, making it an extraordinary case in light of the historical record. Here, we show that this event can be linked to unprecedented seasonal circulation anomalies in the sub‐Antarctic, featuring a dipole around the Antarctic Peninsula that drives the cold advection toward mid‐latitudes. Our index suggests that conditions have become more favorable for cold surges over mid‐latitudes with a repetition of widespread snow over mid‐latitudes in 2009. Copyright © 2010 Royal Meteorological Society