Defense
Student: Geraldo Deniro Gomes
Program: Meteorology
Title: “Numerical Modeling of Heavy Rainfall in the Metropolitan Area of São Paulo:
Sensitivity to Physical Parameterizations and Urban Characteristics"
Advisor: Profa. Dra. Rosmerí Porfírio da Rocha - IAG/USP
Judging Comitee:
- Prof. Dra. Rosmeri Porfírio da Rocha (orientadora) - IAG/USP
2. Prof. Dr. Wallace Figueiredo Menezes – UFRJ (videoconferência)
3. Prof. Dr. Helber Barros Gomes – UFAL (videoconferência)
4. Dr. Mario Eduardo Gavidia Calderón - Pos-Doc - IAG/USP
5. Profa. Dra. Maria Elisa Siqueira Silva – FFLCH/USP
Abstract:
The São Paulo Metropolitan Region (RMSP) experiences recurring heavy rainfall
events that cause flooding, landslides, and river overflows, resulting in material
damage and human losses. In this scenario, improving numerical weather
forecasting is essential for urban planning and risk mitigation. However,
atmospheric numerical models still present considerable uncertainty when
representing the complexity of the urban environment, which directly influences
atmospheric processes. To overcome these limitations, urban canopy models
(UCMs), combined with land use and land cover classification by local climate zones
(LCZs), have been incorporated into numerical models, allowing for a more realistic
representation of the urban area. This study investigated how physical
parameterizations and urban characteristics affect the simulation of extreme rainfall
events in megacities. Simulations were conducted with the WRF model at horizontal
resolutions of 9, 3, and 1 km for the February 10, 2020, event in the RMSP.
Different cloud microphysics and planetary boundary layer schemes were evaluated
to identify the most appropriate combination. Experiments were also conducted
with ZCLs and three MDU schemes: Single Layer Urban Canopy Model (SLUCM),
Building Effect Parameterization (BEP), and BEP coupled with the Building Energy
Model (BEP+BEM). Simulations at 1-km resolution, combined with the combination
of the Bougeault-Lacarrère planetary boundary layer and Morrison cloud
microphysics, reduced the forecast errors for the timing, intensity, and spatial
distribution of extreme rainfall. The inclusion of ZCLs, compared to a more
simplified scheme, improved the representation of the spatial pattern of rainfall,
although it underestimated intensity. The MDU scheme that simulated the spatial
pattern and intensity of rainfall closest to observations was BEP+BEM. It is
concluded that the simulation of intense rainfall in urban environments strongly
depends on the appropriate choice of physical schemes, spatial resolution, and the
inclusion of more complex urban models and use of col. These factors are crucial to
improve forecasting and support hydrometeorological risk management in
megacities.
Keywords: Heavy Rainfall,Cloud Microphysics,Planetary Boundary Layer,Numerical
Simulations,LCZ,UCM