Date of Award

1-1-2022

Language

English

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Atmospheric and Environmental Sciences

Content Description

1 online resource (vi, 75 pages) : illustrations (some color), maps (chiefly color)

Dissertation/Thesis Chair

Junhong Wang

Keywords

Urban heat island, Meteorological stations, Meteorology

Subject Categories

Atmospheric Sciences

Abstract

The New York City Micronet (NYC Micronet), comprised of 17 stations, was installed in the Fall of 2020 for the purpose of long-term monitoring of climate change, and to provide support to utility operations for Consolidated Edison, Inc. (Con Edison). There are five additional standard NYS Mesonet stations located in NYC installed in late 2017. Co-located at the standard stations are three flux, and three profiler stations from sub-networks within the NYS Mesonet. With 22 different locations collecting 5-minute averaged data, this network becomes the highest spatial and temporal resolution urban meteorological network (UMN) of this quality in NYC. This thesis presents methods for UMN metadata collection, classification of urban observation sites, and siting impacts on data within NYC. In this study, classification schemes proposed by others are adopted and modified for NYC for the first time, and used to better describe the impacts that site locations may have on the observed data. Crucial metadata collected include nearby obstruction descriptions, aspect ratio, land-use, percent of impervious surface, rooftop heights, and distance from the city center. Classifications incorporate a number of these metadata, although it is found that distance from the city center and differences between rooftop and ground stations are not effectively accounted for in proposed classifications schemes. Parameters impacted by siting discussed in this study are solar radiation, temperature, and wind speed and direction. We found the quality of incoming solar radiation data is most impacted by obstruction differences between rooftop and ground stations, temperature variability is primarily explained by distance from the city center and percent build around the site, and wind speed and direction are largely influenced by the urban canyon geometry. Spatial and temporal characteristics of the urban heat island (UHI) are studied using 1-year NYC Micronet data from December 1, 2020 to November 31, 2021. An analysis of the UHI is done using two different rural reference regions, the lower Hudson Valley (LHV) and Long Island (LI), for comparison with urban temperatures. Although LI stations have a similar latitude to NYC, the suburban, coastal environment significantly underestimates the UHI magnitude. Therefore, it is recommended to define the UHI as the differences between the city and the LHV. Seasonal UHI intensity (UHII) frequency distribution shows a wider distribution during Spring and Summer due to a higher frequency of urban cooling the Spring and a higher frequency of UHII values greater than 6 °C in the Summer. The UHI also shows a significant seasonal cycle with strongest intensity in Fall and weakest in Winter. The UHI has strong and consistent diurnal cycle in all seasons and maximizes at night. A preliminary analysis is also conducted to understand the observed UHI variability including the impacts of winds and sea breeze. It is found that stronger wind speeds lead to weaker UHI magnitudes. Lastly, it is also found that in the summer of 2021, the sea breeze did not impact averaged UHI but it may impact the coastal stations’ individual UHI magnitudes.

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