Banca de QUALIFICAÇÃO: THALES NUNES SÁ

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : THALES NUNES SÁ
DATE: 28/08/2025
TIME: 09:00
LOCAL: Remota
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: 32
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SPECIALTY: Micrometeorologia
SUMMARY:

The energy balance is the main ecological process associated with CO₂ exchange in terrestrial ecosystems, acting as a trigger for the hydrological and carbon biogeochemical cycles. It reflects the water status and the phenological stage of vegetation through the partitioning of net radiation into surface fluxes. The Eddy Covariance (EC) technique represents the state of the art for determining energy balance and biosphere–atmosphere mass exchange. However, a frequent discrepancy is observed between the sum of turbulent fluxes and the available energy, ranging from 10% to 30%, well above the 5% reported in the literature. This mismatch, known as energy balance closure, is a key parameter for assessing the reliability of fluxes, including CO₂. This study aims to evaluate energy balance closure in a rainfed tropical pasture located in the coastal region of Rio Grande do Norte, Brazil, using the linear regression method. It also investigate the relationship between energy balance closure and parameters related to turbulence and atmospheric instability, such as friction velocity, atmospheric stability (z/L), and turbulent kinetic energy. The results indicated a slope of 0.72, showing that 72% of the available energy was converted into turbulent fluxes of latent and sensible heat, with a coefficient of determination (R²) of 0.92. The intercept was 11.6 W m⁻². The observed closure (72%) is considered satisfactory and ensures reliability in estimating heat and mass exchanges between the pasture and the atmosphere.

COMMITTEE MEMBERS:
Interno - 2086472 - BERGSON GUEDES BEZERRA
Interno - 1752417 - CLAUDIO MOISES SANTOS E SILVA
Interno - 1753398 - PABLO ELI SOARES DE OLIVEIRA