Study of the phenomena of urban heat island in northeast of brazil in the states of ceará and rio grande do norte

This work has the purpose of analyzing the formation of the Urban Heat Island (UHI) in the Northeast of Brazil (NEB) in some cities of the state of Ceará and Rio Grande do Norte. The UHI is a climatic phenomenon that occurs from the elevation of the temperature of an urban region compared to the rural region. Heat conduction is higher in the urban environment because of the physical properties of building materials, which consequently contribute to the increase in temperature contrast in relation to areas with more vegetation. The data used refer to the period from January 2000 to March 2016. These data are part of the Land Surface Temperature (LST) captured by the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor, product MOD11 (Land Surface Temperature and Emissivity). Through these data, mean temperatures were obtained in the urban and rural regions, with the purpose of comparing them for the identification of UHI. In the city of Fortaleza, the maximum variation of diurnal temperature analyzed was in the first quarter of 2014, reaching 4ºC. In the first semester of each year the variation remained constant in average 2,5ºC. In the night period, the maximum variation occurred in the third quarter of 2011, where the variation reached 2.5ºC. The daytime UHI in the city of Sobral shows seasonality in the urban heating patterns during the day. The variation of the maximum diurnal temperature analyzed occurred in the years of 2004 and 2012, surpassing the 3.0ºC. In the city of Mossoró, the UHI presents a seasonal heating pattern, with the maximum variation of diurnal temperature analyzed being 3.5ºC.