@InProceedings{EgitoBatiClemBuri:2015:VeWi34,
author = "Egito, F{\'a}bio and Batista, Paulo Prado and Clemesha, Barclay
Robert and Buriti, Ricardo A.",
affiliation = "{Universidade Federal do Oeste da Bahia (UFOB)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Universidade Federal de Campina
Grande (UFCG)}",
title = "Vertical winds and 3-4 day momentum flux in the MLT inferred from
meteor radar measurements",
year = "2015",
organization = "International Congress of the Brazilian Geophysical Society, 14.",
abstract = "Planetary scale waves in equatorial region transport a significant
amount of energy and momentum through atmosphere. Quantifying the
momentum transported by these waves and its effects toward the
mean flow is rather important. Direct estimative of the momentum
flux transported by these waves requires horizontal and vertical
wind measurements. Ground-based meteor radars have provided
continuous and reliable measurements of the horizontal wind
components in the MLT region. On the other hand, vertical wind
component does not present the same reliability. However, an
approach presented by Babu et al. (2012), made possible to
calculate tridimensional daily winds by using only near zenith
echoes detected around their maximum counting rate, i.e., during
early morning hours. From daily tridimensional winds, momentum
fluxes due to planetary scale waves can be estimated. Following
this approach, we have used measurements performed by a meteor
radar installed at S{\~a}o Jo{\~a}o do Cariri (7.4ºS; 36.5ºW) in
order to measure vertical winds and after determine the momentum
flux transported by these waves. Vertical wind presents magnitudes
of a few meters per second and occasionally reaches magnitudes
higher than 10 m/s. Below 92 km vertical wind is upward during the
whole year and above exhibits a semi-annual oscillation with
downward phase during the equinoxes. Variations associated to
planetary scale waves in the vertical wind are also observed and
some of them appear simultaneously in the zonal and meridional
wind. Vertical transport of zonal momentum fluxes of 3-4 day
component is found to be maximum near autumn equinox, when its
value reaches almost 20 m2s -2, while minimum momentum fluxes were
observed before winter solstice.",
conference-location = "Rio de Janeiro, RJ",
conference-year = "3-6 Aug.",
urlaccessdate = "26 abr. 2024"
}