Variations in Atmospheric CO2 Mixing Ratios across a Boston, MA Urban to Rural Gradient

Brittain Briber, Lucy Hutyra, Allison Dunn, Steve Raciti, J. Munger
2013 Land  
2013. Variations in atmospheric \(CO_2\) mixing ratios across a Boston, MA urban to rural gradient. Land 2(3): 304-327. Published Version Abstract: Urban areas are directly or indirectly responsible for the majority of anthropogenic CO 2 emissions. In this study, we characterize observed atmospheric CO 2 mixing ratios and estimated CO 2 fluxes at three sites across an urban-to-rural gradient in Boston, MA, USA. CO 2 is a well-mixed greenhouse gas, but we found significant differences across
more » ... 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 CO 2 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. OPEN ACCESS Land 2013, 3 305
doi:10.3390/land2030304 fatcat:jzeriefs5rhkvoanouwmejhw44