RISCURI ŞI CATASTROFE, NR. XIV, VOL. 17, NR.2/2015 7 METHODS TO DETECT ATMOSPHERIC AND SURFACE HEAT ISLANDS IN URBAN AREAS I. HERBEL 1 , A. E. CROITORU 2 , A. M. IMBROANE 3 , D. PETREA 4 ABSTRACT. – Methods to detect atmospheric and surface heat islands in urban areas. Intensification of the urbanization process and its associated climatic effects is nowadays a major problem of large cities worldwide. One of these climatic effects is the urban heat island (UHI), that implies increased air and surface temperature values in the city when compared to the nearby rural areas. This phenomenon threatens the health of the population, especially during heat waves, affects the quality of the environment and the quality of life, and also generates significant costs to ensure the inhabitants' thermal comfort. In this study we present a review of the UHI concept and three of the main methods used to detect the atmospheric and surface urban heat islands. Satellite image data analysis seems an easier and time-saving solution, but due to its limitations, we consider that a combination of both surfaces and lower atmospheric layer temperature data analysis is the best choice in order to get accurate results of the intensity and spatial extension of the UHI. Key words: urban heat island, atmospheric urban heat island, surface urban heat island, satellite data, direct measurements 1. INTRODUCTION In the last decades, cities worldwide have experienced accelerated development. Besides the positive aspects of this process, the environmental impact of urbanization is nowadays a major problem in the urban development studies. One of the most important consequences of the urbanization process is the urban heat island (UHI). This phenomenon generates higher temperature values of the air (atmospheric urban heat island - AUHI) and of the surfaces (surface urban heat island – SUHI) when compared to nearby rural areas. 1 Babeş-Bolyai University, Faculty of Geography, 400006, Cluj - Napoca, Romania, e-mail: ioana.herbel@yahoo.com 2 Babeş-Bolyai University, Faculty of Geography, 400006, Cluj - Napoca, Romania, e-mail: croitoru@geografie.ubbcluj.ro 3 Babeş-Bolyai University, Faculty of Geography, 400006, Cluj - Napoca, Romania, e-mail: alex@geografie.ubbcluj.ro 4 Babeş-Bolyai University, Faculty of Geography, 400006, Cluj - Napoca, Romania, e-mail: dpetrea@geografie.ubbcluj.ro