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Title: New York City Impacts on a Regional Heat Wave

Abstract Extreme heat events are projected to increase in magnitude and frequency throughout this century due to increasing global temperatures, making it critically important to acquire improved understanding of their genesis and interactions with large cities. This study presents an application of the factor separation method to assess combined impacts of a synoptic scale heat wave, urban land cover, and urban energy and momentum fluxes on temperatures and winds over New York City via use of high resolution simulations (1 km grid spacing) with an urbanized WRF model. Results showed that, while the heat wave had the largest contribution to temperatures (> 8°C), urban surface factors matched it in highly urbanized areas. Surface factors matched this in highly urbanized areas during night and early morning hours, with contributions up to 5°C, when calm land breeze conditions result in a strong urban heat island. Positive interactions between all factors during morning and nighttime indicate urban heat island amplification of up to 4°C during the heat wave. Midtown Manhattan vertical cross-sections, where urban canopies are most dense, showed a change in the sign (from positive to negative) of the contribution of the urban fluxes between night and day below 500 m, possiblymore » due to radiation blocking and increased thermal storage by buildings as well as frictional effects opposing the incoming warm air.« less
 [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Dept. of Mechanical Engineering
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Environmental and Climate Sciences Dept.
  3. National Weather Service New York Office, Upton, NY (United States)
  4. San Jose State Univ., San Jose, CA (United States). Dept. of Meteorology and Climate Science
Publication Date:
Report Number(s):
Journal ID: ISSN 1558-8424
Grant/Contract Number:
SC0012704; CNS-0958379; CNS-0855217; ACI-1126113
Accepted Manuscript
Journal Name:
Journal of Applied Meteorology and Climatology
Additional Journal Information:
Journal Volume: 57; Journal Issue: 4; Journal ID: ISSN 1558-8424
American Meteorological Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Science Foundation (NSF)
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; urban heat island; heat waves; WRF; factor separation
OSTI Identifier: