New York City Thermal Cycle Assessment and Neighborhood Temperature Variations Due to the Urban Heat Island

The urban heat island and recent increases in overall air temperature are a substantial threat to the life of New York City residents. The impact of extreme climate events and high temperatures on human health has been the subject of much research and studies have shown that during extreme weather conditions the mortality rate in urban areas increases. Cities are comprised of a wide variety of urban settings and various neighborhoods have different physical responses to meteorological events so it is expected that the temperature and heat stress across a given city will fluctuate sharply. Therefore, this research has focused on neighborhood-scale field campaigns to downscale temperature and air quality predictions from city to neighborhood scale in NYC. In order to assess the temperature variability within the city at street level, during the hottest part of the day, this project used eight mobile units bearing temperature and relative humidity sensors, as well as ten weather stations mounted on light poles in various NYC neighborhoods. This study also looks at fine scale structures in the urban heat island of Manhattan at street level through an infrared camera with the spectral range of 7.5-13 µm in order to relate heat and emissions from building surfaces to land surface characteristics such as building density, vegetation coverage, proximity to water, and albedo. LandSat TM5 images were used (with 30 m resolution) for land surface classification. During the summer and early fall of 2011, 2012 and 2013 extensive field campaigns were performed, the results of which show some persistent patterns that could be related to surface characteristics. This work is a collaboration between the health component of the Consortium for Climate Risk in the Urban Northeast (CCRUN), funded by NOAA Regional Integrated Science Assessment (RISA), and New York University Center for Urban Science and Progress (CUSP).