A case study of air quality above an urban roof top vegetable farm.
The effect of elevation and rooftop configuration on local air quality was investigated at the Brooklyn Grange rooftop farm during a short-term observational campaign. Using multiple particle counters and sonic anemometers deployed along vertical gradients, we found that PM2.5 concentration decayed with height above the street. Samples adjacent to the street had the highest average PM2.5 concentration and frequent stochastic spikes above background. Rooftop observations 26 m above ground showed 7-33% reductions in average PM2.5 concentration compared with the curbside and had far fewer spikes. A relationship between the vertical extinction rate of PM2.5 and atmospheric stability was found whereby less unstable atmosphere and greater wind shear led to greater PM2.5 extinction due to damped vertical motion of air.
Center for Green Buildings and Cities, Graduate School of Design, Harvard University, Cambridge, MA 02138, USA.
Zheming
Z
Tong
Section of Horticulture, School of Integrative Plant Science, Cornell University, Room 23 Plant Science Building, Ithaca, NY 14853, USA. Electronic address: thw2@cornell.edu.
Thomas H
TH
Whitlow
Department of Entomology, NYAES, 312 Barton Lab Cornell University Geneva, NY 14456, USA.
Andrew
A
Landers
Brooklyn Grange Flagship Farm 37-18 Northern Blvd. Long Island City, NY 11101, USA.
Benjamin
B
Flanner
D000383:Agriculture / Q000379:methods*; D000388:Air / Q000032:analysis / Q000592:standards*; D000393:Air Pollutants / Q000032:analysis*; D002958:City Planning; D004784:Environmental Monitoring / Q000379:methods*; D009519:New York City; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D014675:Vegetables / Q000254:growth & development*; D014919:Wind
D000393:Air Pollutants; D052638:Particulate Matter
Atmospheric stability; Dry deposition; Intensive green roof; PM(2.5) gradients; Urban farming