@Article{CavalcantiKaya:1999:HiPaAt,
author = "Cavalcanti, Iracema Fonseca Albuquerque and Kayano, Mary T.",
affiliation = "{CPTEC-INPE-Cachoeira Paulista-12630-000-SP-Brasil}",
title = "High-frequency patterns of the atmospheric circulation over the
Southern Hemisphere and South America",
journal = "Palaeogeography, Palaeoclimatology, Palaeoecology",
year = "1999",
volume = "69",
number = "3-4",
pages = "179--193",
keywords = "eddy statistics, vortices, Atlantic.",
abstract = "Daily 500-hPa geopotential height and 250-hPa meridional wind
reanalyzed data obtained from the National Centers for
Environmental Prediction are used to document austral winter (May
to September) and summer (November to March) high-frequency
variability in the Southern Hemisphere (SH) midlatitudes for the
1990-1994 period. Empirical orthogonal function (EOF) technique is
used to determine the high-frequency patterns for these variables
in selected areas. The high-frequency anomalous 500-hPa
geopotential height patterns for two areas in the SH midlatitudes
(the zonally global domain and the western hemisphere) and the
high-frequency anomalous 250-hPa meridional wind patterns in the
western hemisphere between 15 degrees N and 70 degrees S are
discussed. The high-frequency winter and summer patterns for both
variables feature a wavetrain structure in the SH midlatitudes
which is related to synoptic-scale systems, such as cyclones and
anticyclones associated with frontal zones. The dominant
high-frequency patterns in the SH midlatitudes manifest in the
eastern hemisphere while the secondary ones appear in the
southeastern Pacific. Analysis of the western hemisphere data
reveal that the wavetrain in the South American sector extends
northeastward over the continent, thus affecting the regional
weather conditions. An important result presented here concerns
the preference of the intense synoptic systems in the eastern
hemisphere and in the southeastern Pacific to occur in a
sequential instead of an intermittent fashion. This result might
have a potential for being used in weather monitoring.",
copyholder = "SID/SCD",
issn = "0031-0182",
language = "en",
targetfile = "Cavalcanti_High_frequency patterns.pdf",
urlaccessdate = "02 maio 2024"
}