ANALYSIS OF THE RADIATIVE BALANCE IN QUEIROZ FILHO AVENUE – SAO PAULO, BRAZIL UNDER CLEAR SKY CONDITION DURING THE DRY SEASON

Abstract

The radiative balance and the wall temperatures of an urban canyon in the city of São Paulo is remotely observed through the use of radiometers and precision infrared thermometers (IRTs). These instruments are set up on a mobile platform, which moves through the bottom of the canyon. The radiative and thermal patterns are verified, along a traverse, through the different kinds of soil coverage and occupation, during the early hours of a diurnal period and also during a nocturnal period in the dry season. Air temperature measurements are also taken as well as estimates of the spatial temperature distribution, between the atmosphere and urban buildings. The presence of an atmospheric urban temperature gradient is well identified around the area without vegetation coverage, with a maximum magnitude between 6°C and 12ºC. Under the vegetated area it appears that this phenomenon is not pronounced, although a negative net long-wave radiation flux of around 60 Wm-2 between the bottom analyzed surface and the atmosphere is identified. Key-words: mobile transect, wall temperature, urban climate.