@InProceedings{KubotaBona:2010:VaPrSo,
author = "Kubota, Paulo Yoshio and Bonatti, Jose Paulo",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)}",
title = "Variability of precipitation in South America for short term
forecast",
booktitle = "Posters",
year = "2010",
organization = "The Meeting of the Americas.",
publisher = "AGU",
keywords = "land, atmosphere interactions.",
abstract = "This study investigated the behavior of the variability of
precipitation in South America under different surface forcing and
vertical diffusion, based on the assumption that the surface is an
important reservoir of energy. It was used the Atmospheric General
Circulation Model of the Center for Weather Forecasting and
Climate Studies (AGCM-CPTEC/INPE) at the spectral resolution
TQ0213L042 (~ 60 km and 42 vertical layers). It was implemented
the SiB2 and IBIS-2.6 surface schemes and boundary layer
parameterization of Holtslag Boville modified with different
setting options of closure for the calculation of diffusion
coefficient. It was performed for each day during the period of
January 1, 2003 to January 10, 2003, several simulations
(experiments) with forecasting up to 10 days and different
physical combinations of surface and planetary boundary layer
parameterizations. The initial conditions used were the analysis
of the NCEP in the spectral resolution TQ0254L064 degraded to
model resolution and the sea surface temperature in the resolution
of 1 degree, interpolated to model grid. The analyses are based on
the set of simulations produced by physical experiments, where
each member of this group is compared to TRMM3b42 precipitation
data, analysis of the NCEP and the average of the members. The
modification of surface parameterization schemes showed results
with significant dispersion of precipitation as expected, due to
differences in the parameterization formulations. In relation to
the closure options of the boundary layer it was not seen so much
dispersion of precipitation with respect to the control
experiment. To explain the dispersion of precipitation it was
applied the wavelet analyses on the time series of net of energy
on the surface obtained from the energy balance variables of the
experiments. It was removed from the average of the diurnal cycle
to verify the dispersion of the sign of the surface net of energy
(ground, canopy). This method proved to be efficient because, it
has shown qualitatively how the energy stored in surface
dissipates for periods longer than one day. It also shows how the
energy stored during the diurnal cycle may influence the
maintenance of precipitation for a period of time longer. This
behavior can be defined as a signal memory of the surface balance
energy of the diurnal cycle. With the wavelet analyses of the
surface balance energy and the dispersion of precipitation of the
members in relation to control and TRMM3B42 it was concluded that
although more simplified the SSiB scheme represents well the
precipitation and the surface balance energy and presents a clear
signal for periods of 1 to 3 days corresponding to the areas where
precipitation occurs. The SiB2 scheme has the same pattern, but
overestimates the precipitation in the Amazon region. The IBIS
scheme maintains the standard underestimating the precipitation in
the central region of Brazil.",
conference-location = "Foz do Igua{\c{c}}u",
conference-year = "8-12 aug.2010",
language = "en",
targetfile = "kubota_variability.pdf",
urlaccessdate = "29 jun. 2024"
}