Banca de DEFESA: LOURDES GABRIELA VIEIRA BATISTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LOURDES GABRIELA VIEIRA BATISTA
DATE: 31/08/2022
TIME: 09:00
LOCAL: Videoconferência
TITLE:

Analysis of the fog formation process at the airports of Manaus-AM

KEY WORDS:

Fog, Manaus Airport, PAFOG, Operational Forecast Model

PAGES: 132
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SUMMARY:

Analyzing the fog formation processes in Manaus-AM and creating an operational
forecasting model are the main purposes of this work. The frequency of fog occurrence
in Manaus and the paucity of publications on the phenomenon in the northern region of
Brazil motivated the study of the causes and local influences in fog formation process.
From the 10 years of data, 30 most intense events were selected for the dry and rainy
seasons. The analysis consisted of: (1) Analysis of surface variables (Air temperature at
2m (T), Dew Point Temperature (Td), Relative Humidity (RH), wind direction and
speed, and precipitation), (2) Thermodynamic analysis (Vertical temperature and
humidity profiles constructed by reanalysis data) and (3) Synoptic Analysis (Streamline,
divergence and omega fields constructed by the reanalysis data). The PAFOG model
was also used to evaluate its applicability for the Northern region. The observed results
did not show significant differences between the dry and rainy seasons. In both seasons
the average temperature was 23°C; T-TD between 0 and 2°C, wind direction between
220 and 50° and wind speed between 00 and 03KT. There was precipitation preceding
the event in most cases. In Ponta Pelada, the surface variables analyzed individually, are
consistent with a scenario less favorable to formations, but the average conditions
showed high relative humidity (between 94 and 100$\%$) and T-TD between 1 and
2°C. Wind direction was the variable that most diverged between airports. Although the
speed was weak (<3 knots) for all cases analyzed, the predominant direction in Eduardo
Gomes, in all stations, was north-northwest, while in Ponta Pelada it was not possible to
determine the predominance, due to variations observed. The thermodynamic profiles
showed that fogs in Manaus are formed under the next conditions: 1- conditionally
unstable atmosphere; 2 - weak or no inversion; 3 - wet layer up to 900hPa. The active
synoptic systems that influenced fog formations during the rainy season were Upper
Tropospheric Cyclonic Vortex, Bolivian High and Trough at the high level in the
northeast region. During the dry season, there was influence of anticyclones and ridges
in the North, Northeast and Midwest, in addition to the systems of the northern
hemisphere. The predictability of the PAFOG model was considered satisfactory for all
cases analyzed and the forecast was classified as good/excellent. The results allowed the
construction of an operational model with favorable conditions for fog formation in
Manaus in observational, synoptic, and thermodynamic aspects. This model is important
to help forecast and mitigate the impact of fog on the operational sector and can be used
as a starting point for improvement and creation of new forecasting methods for the
northern region.

BANKING MEMBERS:
Externo à Instituição - CLEBER SOUZA CORREA
Interna - 1653612 - MARIA LUCIENE DIAS DE MELO
Presidente - 1099304 - NATALIA FEDOROVA
Externa à Instituição - ROSA MARIA NASCIMENTO DOS SANTOS
Interno - 2227105 - VLADIMIR LEVIT