VARIABILIDAD ESPACIO-TEMPORAL DE LA ISLA DE CALOR SUPERFICIAL EN TRES CIUDADES ARGENTINAS.

This paper investigates the spatiotemporal variations of the Surface Urban Heat Island (SUHI) computed as the difference of urban and rural land surface temperatures for the three major cities of Argentina: Buenos Aires, Rosario, and Cordoba. Satellite-based data of 1 km x 1 km resolution available through the Global Surface UHI Explorer were used to estimate mean and maximum values, trends and percentage of each urban area with positive/negative intensities of SUHI for the period 2003-2017. Results indicate that, on average the nocturnal urban surface temperature is higher than the rural one (positive SUHI) for the annual, winter and summer mean for the three cities. The greatest contrast corresponds to Buenos Aires, where the maximum SUHI magnitude is +2°C in summer and the minimum is +1,5°C in winter. Both Rosario and Cordoba exhibit a difference in magnitude between summer and winter of only 0,1°C. The percentage of the area of each city with nocturnal surface temperatures greater than the rural ones is on average, 93 % for Buenos Aires, 97% for Rosario and 89% for Cordoba. During daytime, in some cases the SUHI intensity is negative generating a cold island. This effect is observed in the three cities during the cold season and in Rosario and Cordoba for the annual mean. In Buenos Aires, that hosts more than 30 % of the total population of the country, there is a significant positive trend in the daytime mean and maximum SUHI intensity. The comparison between the Buenos Aires' SUHI and canopy UHI (derived from standard air temperature measurements) shows positive intensities during night-time in both cases, although the mean annual and summer SUHI are warmer than the UHI in +0,3°C and +0,6°C, respectively. Additionally, there is a trend towards warmer daytime intensities of both types of heat islands. [ABSTRACT FROM AUTHOR]