Assinaturas de radar polarimétrico de sistemas precipitantes atuantes no Leste do Nordeste do Brasil
A Doppler S-Band polarimetric weather radar is an important tool for estimation precipitation and, consequently, for assenssing of meteorolofical systems operating in the region covered by the radar. Currently, we have a radar installed in the city of Parnamirim (metropolitan region of Natal), Ri...
Na minha lista:
Autor principal: | |
---|---|
Outros Autores: | |
Formato: | Dissertação |
Idioma: | pt_BR |
Publicado em: |
Universidade Federal do Rio Grande do Norte
|
Assuntos: | |
Endereço do item: | https://repositorio.ufrn.br/handle/123456789/32688 |
Tags: |
Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
|
Resumo: | A Doppler S-Band polarimetric weather radar is an important tool for estimation
precipitation and, consequently, for assenssing of meteorolofical systems operating in the
region covered by the radar. Currently, we have a radar installed in the city of Parnamirim
(metropolitan region of Natal), Rio Grande do Norte, in the East of Northeast Brazil,
operated by the National Center for Monitoring and Natural Disaster Alerts (Cemaden).
Due to the ability of the radar to estimate precipitation in three dimensions and the physical
properties of hydrometeors, this work proposes the following objectives: i) validate the
radar estimates with automatic rain gauges, ii) evaluate the polarimetric characteristics of
the precipitating systems in the year 2014 and iii) analyze a natural disaster event that
occurred in the region using radar data. The study area is centered on the area monitored
by radar with a coverage of 181 thousand km2
, which was divided into two sub-regions for
a more punctual analysis in which they were defined as R1 (West Region) and R2 (East
Region) were defined for presenting different precipitation regimes. For this, data from the
polarimetric variables were used: horizontal reflectivity, differential reflectivity, specific
differential phase and correlation coefficient extracted from the volumetric sweeps of the
radar and data from 4 rainfall stations from Cemaden and INMET that are distributed in
the state of Rio Grande do Norte. The data were used in statistical analysis with the
generation of representative fields, for example, frequency histograms and vertical mean
profiles. The validation of the radar data showed the instrument's ability to estimate the
daily precipitation of the regions, presenting an average BIAS of approximately -5 mm/day
and an average correlation of 0.74. The radar showed high sensitivity in the warm and
mixed phases of the precipitating systems with different top heights of 20 dBZ, in addition
to showing that the two regions studied have completely different microphysical
signatures, with R1 marked by intense and deep convection, with systems reaching height
of 15 km with top of 20 dBZ and R2 marked by stratiform precipitation. This study is the
first to use polarimetric radar data to present the microphysical differences of the systems
in Northeast Brazil, therefore it represents a significant contribution in the literature. |
---|