Banca de DEFESA: THALES NUNES SÁ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : THALES NUNES SÁ
DATE: 27/02/2026
TIME: 09:00
LOCAL: Laboratório de Informática
TITLE:

Energy balance of tropical pasture (Brachiaria brizantha) under grazing conditions in the coastal region of Rio Grande do Norte

KEY WORDS:

Eddy Covariance; Energy balance closure; Turbulent fluxes; Tropical pasture

PAGES: 67
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SPECIALTY: Micrometeorologia
SUMMARY:

This study investigated the energy balance dynamics of a tropical Brachiaria brizantha pasture in Rio Grande do Norte using the Eddy Covariance (EC) technique. The main objective was to quantify energy balance closure and to analyze the influence of seasonality and atmospheric parameters on both the closure and the partitioning of the energy balance. The results showed that energy balance closure ranged between 69% and 73%, indicating a systematic deficit in turbulent flux estimates relative to the available energy. The level of closure achieved is considered satisfactory to ensure the reliability of heat and mass exchange measurements. The best energy balance closure occurred under conditions of strong turbulence (high TKE and u*) and near-neutral atmospheric stability, whereas nighttime periods exhibited lower closure due to weak turbulent mixing. A counterclockwise hysteresis pattern was also observed, with improved energy balance closure in the afternoon as a result of the release of stored energy. Energy partitioning was mainly modulated by water availability. During the rainy season, latent heat flux (LE) predominated (Bowen ratio = 0.59), driven by high evapotranspiration rates and increased leaf area index (LAI). In contrast, during the dry season, water limitation reversed this pattern, making sensible heat flux (H) dominant (Bowen ratio = 3.16). The study also highlighted the spatial representativeness of the measurements, as footprint analysis indicated that approximately 90% of the measured flux originated from an area located about 40 m from the flux tower.

COMMITTEE MEMBERS:
Interno - 2086472 - BERGSON GUEDES BEZERRA
Interno - 1752417 - CLAUDIO MOISES SANTOS E SILVA
Interno - 1753398 - PABLO ELI SOARES DE OLIVEIRA
Externo à Instituição - LUIS MARCELO DE MATTOS ZERI - CEMADEN