Highly urbanized and industrialized cities across the globe have been known for a long time to be major anthropogenic sources of greenhouse gases (GHGs), yet there is still no consensus on an adequate methodology to m...Highly urbanized and industrialized cities across the globe have been known for a long time to be major anthropogenic sources of greenhouse gases (GHGs), yet there is still no consensus on an adequate methodology to monitor their ambient concentration. This work describes the initiation of a GHG monitoring program at Bronx Community College (BCC) of the City University of New York (CUNY) in Bronx, New York using a Picarro GHG monitor (Model g2301). Results show average atmospheric levels of carbon dioxide (CO2) and methane (CH4) that are above 400 and 2.0 ppmv, respectively. Similar daily fluctuations, with peaks levels resulting from emissions likely occurring during morning rush hour, indicate that there are common sources for both gases. This monitoring system is replicable, sustainable and scalable and will make it possible to more quantifiably link emissions produced in New York City to their material sources. As more data is collected, reduction projections for GHG-producing materials will more accurately be associated to reduction projections for atmospheric CO2 and CH4 levels originating in New York City. In the process, empirical models on air exchange rates and convective boundary layer homogenization through turbulence could also be improved.展开更多
文摘Highly urbanized and industrialized cities across the globe have been known for a long time to be major anthropogenic sources of greenhouse gases (GHGs), yet there is still no consensus on an adequate methodology to monitor their ambient concentration. This work describes the initiation of a GHG monitoring program at Bronx Community College (BCC) of the City University of New York (CUNY) in Bronx, New York using a Picarro GHG monitor (Model g2301). Results show average atmospheric levels of carbon dioxide (CO2) and methane (CH4) that are above 400 and 2.0 ppmv, respectively. Similar daily fluctuations, with peaks levels resulting from emissions likely occurring during morning rush hour, indicate that there are common sources for both gases. This monitoring system is replicable, sustainable and scalable and will make it possible to more quantifiably link emissions produced in New York City to their material sources. As more data is collected, reduction projections for GHG-producing materials will more accurately be associated to reduction projections for atmospheric CO2 and CH4 levels originating in New York City. In the process, empirical models on air exchange rates and convective boundary layer homogenization through turbulence could also be improved.
基金the National Natural Science Foundation of China(No.20673136,20706056)the National"863"High-Technology Research Program of China(2006AA05Z136,2007AA05Z141)the 100 People Plan Program of the Chinese Academy of Sciences and the Pujiang Program of Shanghai City(No.06PJ14110) for support of this work
