Remotely sensed heat : variation and change in surface urban heat islands in a temperate eco-region of the United States.

Urban heat island (UHI) is a term used to describe increased surface and atmospheric temperatures in an urban core relative to surrounding non-urbanized areas. To examine the variability introduced into derived estimates of the surface UHI, this study constructs and compares multiple remotely sensed indicators of the surface UHI for major metropolitan cities of a temperate eco-region of the United States. The Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day, 500-meter product (MOD11A2) is the source data used to calculate six different RS-derived UHI indicators for the year 2002 to 2012. The different SUHI indicators are evaluated using the Spearmans Rho rank-order correlation statistic to assess agreeability for 2012 and consistency over time 2002 to 2012. Inconsistencies exist in monthly rankings between indicators, and the degree to which the indicators detect change over time. Results suggest that land cover based indicators are highly correlated compared to urban heat island driven indicators in terms of magnitude and change over time