Banca de QUALIFICAÇÃO: GUSTAVO SILVA XAVIER

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : GUSTAVO SILVA XAVIER
DATE: 29/09/2025
TIME: 09:30
LOCAL: Laboratório de Informática - NEClim
TITLE:

Turbulence regime transitions and impacts on the thermal gradient and surface fluxes in the Caatinga.

KEY WORDS:

Nocturnal boundary layer, Turbulence, Regime transition

PAGES: 53
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SPECIALTY: Micrometeorologia
SUMMARY:

Understanding the processes that regulate scalar exchanges between the surface and the atmosphere under very stable conditions remains one of the greatest challenges in boundary-layer meteorology. Flux estimates obtained through the eddy covariance method often present uncertainties, directly affecting the property balance within the boundary layer. An additional and fundamental issue in the study of the nocturnal boundary layer is the transition between turbulence regimes, when, for example, a night may begin under a weakly stable regime (with strong shear and intense turbulence) and evolve into a very stable regime (with weak shear and low turbulence intensity), or the reverse. Despite its importance, there is still limited knowledge about the mechanisms that trigger these transitions and how to predict them. In this context, identifying relationships between internal and external variables, with the aim of detecting behavioral patterns, represents an essential step. Several studies have already reported connections, such as the relationship between wind speed and turbulence intensity, or between wind speed and net radiation, but such analyses have not yet been conducted in the Caatinga biome. Therefore, this study aims to fill this gap by investigating how regime transitions influence temperature gradients and surface fluxes in this ecosystem. As a preliminary result, based on a case study of two nights with opposite regime transitions, it was observed that a decrease or intensification of wind leads, respectively, to an increase or reduction in the temperature gradient, which in turn modulates the evolution of net radiation and establishes a relationship between wind speed and net radiation after the transition.

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