Dissertations, Theses, and Capstone Projects

Date of Degree


Document Type


Degree Name



Earth & Environmental Sciences


Sean Ahearn

Committee Members

Haydee Salmun

Randye Rutberg

Christopher Small

Subject Categories

Environmental Indicators and Impact Assessment | Environmental Monitoring | Other Environmental Sciences




This study aims to characterize the seasonality of New York City thermal environment using Landsat satellite long wave IR data. The main objective is to describe the relationship between surface temperature, air temperature at 2 meters above the surface and urban morphology over the annual cycle. The secondary objective involves identification of the factors contributing to surface temperature variability. Landsat thermal scenes, ground-based air temperatures and linearly unmixed continuous endmember fractions from the optical bands are used to represent the urban environment in the analysis. Spatial resolution, solar and view geometry and land cover are important components influencing measurements of the thermal field. The parallel consideration of air temperature and surface temperature makes possible the distinction between locally produced versus advected heat. Landsat is selected for its extended temporal coverage of thermal scenes, its suitable spatial scale for monitoring the urban environment at neighborhood scale and its temporal consistency with overlapping instruments and view paths.

Unique features of this study include use of decameter resolution, time series analysis of several yearly cycles, rigorous investigation of urban thermal anisotropy using Path 13 and Path 14 sidelap and parallel examination of “locally produced” with advected heat. The use of Substrate-Vegetation-Dark Linear Mixture Model (Small, 2001) is proposed as an alternative to other methods for estimating urban emissivity at pixel level.

Parallel time series analysis of satellite thermography and air temperature at 2m over NY Metropolitan area spanning 27 years showed phase difference between surface and air temperature yearly maxima of up to 9 days.