@ElectronicSource{KouadioMachServ::TrAtCy,
abstract = "We investigate the possibility that hurricanes (H) spreading into
the tropical Atlantic are originally connected with mesoscale
convective systems (MCSs) previously generated on the West African
continent. The analysis is carried out over 2004 and 2005, during
which we find ten cases (six in 2004, four in 2005, all during
July-August-September) for which such a connection can be made.
For each one of the selected cases a backward methodology is
performed using both subjective and objective analyses. This
methodology is summarized as follows: starting from the date and
position of the studied H when it is primarily catalogued as a
tropical depression, we look backward at a possible easterly wave
which may be the physical bond between the H initiation and an MCS
dissipation in the ocean off the African coast. In this subjective
step we use the wave signature from the 700 hPa vorticity at a
6-hour frequency given by the reanalysis of the NCEP, as well as
the MCS dataset provided by the MSG-7 images. Having associated
the easterly wave with a sufficiently consequential MCS in terms
of intensity and lifespan, we proceed, in a second step, to an
objective backward analysis to go up to the time until the origin
(date and position) of this MCS. In this second step we adapt a
recent tracking methodology (FORTRACC) to individually track each
MCS at a 30-minute frequency by using a dynamical threshold
temperature. We find that practically all the selected cases (9
out of 10) originate from a roughly limited area over West Africa.
Mostly of MCS-H cases studied, shown an increase in the relative
vorticity after MCS dissipation. As another important result, such
connection between these MCSs which originate in West Africa and
the occurrences of hurricanes takes place when a dipole in the sea
surface temperature (SST) anomaly is observed between the Main
Development Region (MDR) of the hurricanes (positive SST anomaly),
and the equatorial tongue in the Gulf of Guinea (negative SST
anomaly). .",
address = "S{\~a}o Jos{\'e} dos Campos",
affiliation = "University of Cocody, Abidjan, UFR-SSMT, Laboratory of Atmospheric
Physics, 22 BP 582 Abidjan 22,C{\^o}ted’Ivoire. Visiting
Scientist at Divis{\~a}o Sat{\'e}lite e Sistemas Ambiantes
(CPTEC/INPE) and {Instituto Nacional de Pesquisas Espaciais
(INPE/CPTEC)} and Institut de Recherche pour le D{\'e}veloppement
(IRD-UR182), Visiting Scientist at Funda{\c{c}}{\~a}o Cearense
de Meteorologia e Recursos H{\'{\i}}dricos (FUNCEME)",
author = "Kouadio, Yves K. and Machado, Luiz Augusto Toledo and Servain,
Jacques",
keywords = "hurricanes, mesoscale convective systems, tropical Atlantic, SST
dipole.",
language = "en",
lastupdatedate = "2007-12-15",
publisher = "Instituto and Nacional and de and Pesquisas and Espaciais",
ibi = "6qtX3pFwXQZGivnK2Y/SsgSq",
url = "http://urlib.net/ibi/6qtX3pFwXQZGivnK2Y/SsgSq",
targetfile = "v1.pdf",
title = "Tropical Atlantic Cyclogenesis Coming from West African Mesoscale
Convective Systems",
typeofmedium = "On-line",
urlaccessdate = "26 abr. 2024"
}