Open AccessThis article is
- freely available
Variations in Atmospheric CO2 Mixing Ratios across a Boston, MA Urban to Rural Gradient
Department of Earth and Environment, Boston University, 685 Commonwealth Ave., Room 130, Boston, MA 02215, USA
Physical and Earth Sciences Department, Worcester State University, 486 Chandler St., Worcester, MA 01602, USA
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
* Author to whom correspondence should be addressed.
Received: 20 April 2013; in revised form: 12 June 2013 / Accepted: 19 June 2013 / Published: 2 July 2013
Abstract: Urban areas are directly or indirectly responsible for the majority of anthropogenic CO2 emissions. In this study, we characterize observed atmospheric CO2 mixing ratios and estimated CO2 fluxes at three sites across an urban-to-rural gradient in Boston, MA, USA. CO2 is a well-mixed greenhouse gas, but we found significant differences across this gradient in how, where, and when it was exchanged. Total anthropogenic emissions were estimated from an emissions inventory and ranged from 1.5 to 37.3 mg·C·ha−1·yr−1 between rural Harvard Forest and urban Boston. Despite this large increase in anthropogenic emissions, the mean annual difference in atmospheric CO2 between sites was approximately 5% (20.6 ± 0.4 ppm). The influence of vegetation was also visible across the gradient. Green-up occurred near day of year 126, 136, and 141 in Boston, Worcester and Harvard Forest, respectively, highlighting differences in growing season length. In Boston, gross primary production—estimated by scaling productivity by canopy cover—was ~75% lower than at Harvard Forest, yet still constituted a significant local flux of 3.8 mg·C·ha−1·yr−1. In order to reduce greenhouse gas emissions, we must improve our understanding of the space-time variations and underlying drivers of urban carbon fluxes.
Keywords: CO2; emissions; urban; gradient; land cover
Citations to this Article
Cite This Article
MDPI and ACS Style
Briber, B.M.; Hutyra, L.R.; Dunn, A.L.; Raciti, S.M.; Munger, J.W. Variations in Atmospheric CO2 Mixing Ratios across a Boston, MA Urban to Rural Gradient. Land 2013, 2, 304-327.
Briber BM, Hutyra LR, Dunn AL, Raciti SM, Munger JW. Variations in Atmospheric CO2 Mixing Ratios across a Boston, MA Urban to Rural Gradient. Land. 2013; 2(3):304-327.
Briber, Brittain M.; Hutyra, Lucy R.; Dunn, Allison L.; Raciti, Steve M.; Munger, J. W. 2013. "Variations in Atmospheric CO2 Mixing Ratios across a Boston, MA Urban to Rural Gradient." Land 2, no. 3: 304-327.