Open AccessBrazilian Northeast Jet Stream: association with synoptic‐scale systems
Author(s) -
Fedorova Natalia,
Levit Vladimir,
Campos Antonio Marcos Vianna
Publication year - 2018
Publication title -
meteorological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 59
eISSN - 1469-8080
pISSN - 1350-4827
DOI - 10.1002/met.1693
Subject(s) - jet stream , trough (economics) , subtropical ridge , climatology , synoptic scale meteorology , northern hemisphere , westerlies , subtropics , southern hemisphere , environmental science , period (music) , troposphere , geology , wind speed , wind direction , jet (fluid) , meteorology , oceanography , geography , precipitation , physics , fishery , biology , acoustics , economics , macroeconomics , thermodynamics
The association of the Brazilian Northeast Jet Stream (BNEJS) with synoptic‐scale systems was analysed over 16 years (1994–2009) using reanalysis data from the National Center for Environmental Prediction – National Center for Atmospheric Research (NCEP‐NCAR). BNEJS events were divided into three groups, which show the location of the jet stream between synoptic systems at high levels: Type I, a southerly BNEJS between the Bolivian High and upper tropospheric cyclonic vortexes (UTCVs) and/or the trough (UTT) over the ocean; Type II, a northerly BNEJS between the South Atlantic Subtropical High (SASH) and the UTCV (and/or the UTT) over the continent; and Type III, a westerly BNEJS between the UTCV in the Northern Hemisphere and a UTT in the Southern Hemisphere. Throughout the year depending on the characteristics of the BNEJS, three distinct meteorological features were observed. A dry period from December to February in the coastal region was characterized by a relatively small number of fast BNEJSs with a low wind speed in the core, with a dominant southeast direction and with the BNEJS's location between the UTCV and the Bolivian High. A period between April and October (a rainy period and the transition to a dry season in the coastal region) was characterized by a rather high number of fast BNEJSs, with high wind speed in the core, a predominant northwesterly direction, and the location of the BNEJS between the UTT and the SASH. Transitional periods (March and November) have a moderate number of BNEJSs without a high wind speed in the core, with a predominant southwesterly direction, and the BNEJS's position between the UTT and the Bolivian High.