@Article{AnselmoSchuMach:2020:AmLoJe,
author = "Anselmo, Evandro M. and Schumacher, Courtnery and Machado, Luiz
Augusto Toledo",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Texas and
M University} and {Instituto Nacional de Pesquisas Espaciais
(INPE)}",
title = "The amazonian low-level jet and its connection to convective cloud
propagation and evolution",
journal = "Monthly Weather Review",
year = "2020",
volume = "148",
number = "10",
pages = "4083--4099",
month = "Oct.",
abstract = "We describe the existence of an Amazonian low-level jet (ALLJ)
that can affect the propagation and life cycle of convective
systems from the northeast coast of South America into central
Amazonia. Horizontal winds from reanalysis were analyzed during
MarchAprilMay (MAM) of the two years (201415) of the
GoAmazon2014/5 field campaign. Convective system tracking was
performed using GOES-13 infrared imagery and classified into days
with high and weak convective activity. The MAM average winds show
a nocturnal enhancement of low-level winds starting near the coast
in the early evening and reaching 1600 km inland by late morning.
Mean 3-hourly wind speeds maximize at 910 m s\−1 near 900
hPa, but individual days can have nighttime low-level winds
exceeding 12 m s\−1. Based on objective low-level wind
criteria, the ALLJ is present 10%40% of the time over the Amazon
during MAM depending on the location and time of day. The
evolution of the ALLJ across the Amazon impacts the frequency of
occurrence of cloud clusters and the intensity of the moisture
flux. In addition, the ALLJ is associated with the enhancement of
northeasterly flow in the midtroposphere during active convective
days, when vertical momentum transport may be occurring in the
organized cloud clusters. During the weakly active convective
period, the ALLJ is weaker near the coast but stronger across the
central Amazon and appears to be linked more directly with the
South American low-level jet.",
doi = "10.1175/MWR-D-19-0414.1",
url = "http://dx.doi.org/10.1175/MWR-D-19-0414.1",
issn = "0027-0644",
language = "en",
urlaccessdate = "20 abr. 2024"
}