Estimativa de fluxo de calor sensível com suporte de cintilometria – estudo de caso : Cidade Universitária - Ilha do Fundão/RJ

Abstract

The large aperture scintillometer (CinLA) is an optical device used to estimate averaged sensible heat fluxes (H) from fluctuations in the refractive index of the turbulent atmosphere in a light beam spread between a transmitter and a receiver. The present dissertation proposes to study the behavior of the sensible heat production during the day in the University City of the Federal University of Rio de Janeiro (UFRJ), campus of the Fundão Island / RJ, through the use of a CinLA. In particular, the sensitivity of the refractive index structure parameter (Cn2) to changes in the collection time scale and to changes in humidity and air temperature are analyzed. The data were collected, uninterruptedly, between September 23 and October 3, 2016, with the scintillometer installed on the terrace of two buildings on the main campus of UFRJ. In addition, meteorological data provided by the IGEO / UFRJ hydrometeorological station, images of the GOES satellite and synoptic charts were used to characterize the local atmosphere. Preliminary evaluations indicated the option of taking measurements at 5-minute intervals, obtained from subsamples collected every 30 seconds. Sensitivity analysis showed that variations of up to 10 ° C in temperature can alter H values up to 8,8%, while changes of ±10 hPa in atmospheric pressure can produce changes of 1,4% in H. In the experiment conducted, the highest value of H found was 443,98 W.m-2, and the mean value was approximately 64,38 W.m-2.