Local warming in the historical center of Naples

Urban Heat Island (UHI) is a physical process getting more and more hazardous for people living in a large city. It can be influenced by several factors such as geomorphological context, the presence of lakes, rivers or sea, the land use and urban features with special regard to the presence of extended green areas/infrastructures. The metropolitan area of Naples is heavy affected by UHI in a very complex manner due to the simultaneous action of various morphological and orographic factors (e.g. presence of hills and closeness to sea surface) so to prevent the quantification of each percentage weight. This large amount of parameters makes it difficult to identify a clear relationship with urbanization features. Therefore, it is strictly necessary to enhance the knowledge of urban micro-climate by focusing on the evolution of the temperature and relative humidity. To obtain a clearer representation of the process, we propose a methodology based on the collection and the analysis of a specific set of high quality data. An appropriate study of this phenomenon has to be carried on by analyzing directly thermo-hygrometric data measured by appropriate local sensors instead of remote sensing technologies which could lead distorted scenarios. The goal is to characterize the thermal properties of the atmosphere layers below 50 m above the ground. In fact, people live within the “building envelope” that is thermo-hygrometrically regulated. Once the sites are properly identified, the appropriate meteorological methodology can be used to analyze the basic thermo-hygrometric data. This study will provide only a thermo mapping of the metropolitan area of Naples that could be used in improving the city living conditions. The paper briefly describes the UHI phenomenon in the city of Naples and specifically analyzes the meteorological scenarios occurred during the summers 2014 and 2015.