Urban Pollution

The discovery of the thinning of the Antarctic ozone layer every austral spring led to intense discussions at the international level and culminated in the historic agreement of September 1987: the Montreal Protocol on Substances that Deplete the Ozone Layer. Along with the subsequent London Amendment in 1990 and Copenhagen Amendment in 1992, the Protocol called for the elimination of production and consumption of CFC-11, CFC-12, CFC-113, CH3CCl3, CCl4, and halon-1211, among other targeted gases, in developed countries by 1 January 1996.

See also: Harvard Forest

four-channel gas chromatographic system called FACTS (Forest and Atmosphere Chromatographs of Trace Species)
four-channel gas chromatographic system called FACTS (Forest and Atmosphere Chromatographs of Trace Species)
To test the efficacy of this international treaty, measurements of 14 ozone-depleting and/or greenhouse gases were taken above the forest canopy at Harvard Forest every 24 minutes, downwind of the New York City—Washington, D. C. corridor. Using a four-channel gas chromatographic system called FACTS (Forest and Atmosphere Chromatographs of Trace Species), observations of H2, CO, CH4, methyl chloroform (CH3CCl3), chloroform (CHCl3), carbon tetrachloride (CCl4), CFC-11 (CCl3F), CFC-12 (CCl2F2), CFC-113 (C2Cl3F3), halon-1211 (CBrClF2), perchlorethylene (C2Cl4), trichlorethylene (C2HCl3), nitrous oxide (N2O), and sulfur hexafluoride (SF6) began on 15 January 1996 and continued with some interruptions through June 2005.

Harvard Forest is ideally situated for a study of the pollution history of the Northeast urban/industrial corridor. As a trajectory analysis indicates, winds are predominantly from the west, with ‘clean’ background air from the northwest (Canada) and ‘dirty’ polluted air from the southwest (New York City—Washington, D. C. corridor). Because winds from the east are rare (~10% of the time), typically occur during stormy weather, and carry an ocean signal, such data are removed from the data analysis.

For two of the measured gases, CO and PCE (perchlorethylene, C2Cl4, used primarily in dry-cleaning and as a degreasing agent), inventories of ground based emissions are available on a county-wide basis for the Northeast. Using these two species as reference gases, we can determine the annual urban/industrial emissions of the other measured species. For those gases regulated by the Montreal Protocol, our results indicate that, after an initial decade of decline, the post-1996 emissions are not dropping as rapidly as expected or assumed.

This research has been funded by NASA, NOAA, DOE, and Harvard University and has resulted in 1 doctoral thesis, 4 papers, 2 conference presentations, and 1 prize (see Publications below).

For more information, contact Diana Barnes or Elaine Gottlieb.

Publications

Dissertation

Barnes, D. H., Quantifying Urban/Industrial Emissions of Greenhouse and Ozone-Depleting Gases Based on Atmospheric Observations, Ph.D. thesis, Harvard University, 2000.

Articles

Barnes, D. H., S. C. Wofsy, B. P. Fehlau, E. W. Gottlieb, J. W. Elkins, G. S. Dutton, and S. A. Montzka, Urban/industrial pollution for the New York City—Washington, D. C. corridor, 1996-1998: providing independent verification of CO and PCE emissions inventories, J. Geophys. Res., in submission.

Barnes, D. H., S. C. Wofsy, B. P. Fehlau, E. W. Gottlieb, J. W. Elkins, G. S. Dutton, and S. A. Montzka, Urban/industrial pollution for the New York City—Washington, D. C. corridor, 1996-1998: a study of the efficacy of the Montreal Protocol and other regulatory measures, J. Geophys. Res., in submission.

Barnes, D. H., S. C. Wofsy, B. P. Fehlau, E. W. Gottlieb, J. W. Elkins, G. S. Dutton, and P. C. Novelli, Hydrogen in the atmosphere: observations above a forest canopy in a polluted environment, J. Geophys. Res., in submission.

Potosnak, M. J., S. C. Wofsy, A. S. Denning, T. J. Conway, J. W. Munger, and D. H. Barnes, ‘Influence of biotic exchange and combustion sources on atmospheric CO2 concentrations in New England from observations at a forest flux tower,’ J. Geophys. Res., 104: (D8) 9561-9569, 27 April 1999.

Proceedings

Barnes, D. H., J. W. Elkins, and S. C. Wofsy, ‘Urban/Industrial Emissions of Hydrogen,’ Proceedings of American Geophysical Union Fall Meeting Proceedings, 12 December 1999.

Barnes, D. H. and S. C. Wofsy, ‘Evaluation of greenhouse and ozone-depleting gases in rural New England: A prelude to mitigation,’ Proceedings of Ninth Annual Harvard Forest Ecology Symposium, 11 March 1998.

References


Bakwin, P. S., D. F. Hurst, P. P. Tans, and J. W. Elkins, Anthropogenic sources of halocarbons, sulfur hexafluoride, carbon monoxide, and methane in the southeastern United States, J. Geophys. Res., 102, 15915-15925, 1997.

Biraud, S., P. Ciais, M. Ramonet, P. Simmonds, V. Kazan, P. Monfray, S. O’Doherty, T. G. Spain, and S. G. Jennings, European greenhouse gas emissions estimated from continuous atmospheric measurements and radon 222 at Mace Head, Ireland, J. Geophys. Res., 105, 1351-1366, 2000.

Derwent, R. G., P. G. Simmonds, S. O’Doherty, and D. B. Ryall, The Impact of the Montreal Protocol on concentrations in northern hemisphere baseline and European air masses at Mace Head, Ireland over a ten year period from 1987-1996, Atmospheric Environment, 32, 3689-3702, 1998a.

Derwent, R. G., P. G. Simmonds, S. O’Doherty, and D. B. Ryall, European source strengths and northern hemisphere baseline concentrations of radiatively active trace gases at Mace Head, Ireland, Atmospheric Environment, 32, 3703-3715, 1998b.

Environmental Protection Agency, Locating and Estimating Air Emissions from Sources of Perchloroethylene and Trichloroethylene, 1989.

Environmental Protection Agency, Protection of Stratospheric Ozone, Significant New Alternatives Policy Final Rule, rep. 59 (53), pp. 13044, Washington, D. C., March 18, 1994.

Environmental Protection Agency, National Air Pollutant Emission Trends, 1900-1996, EPA-454/R-97-011, 1997.

EPA emissions by county.

Fraser, P., D. Cunnold, F. Alyea, R. Weiss, R. Prinn, P. Simmonds, B. Miller, and R. Langenfelds, Lifetime and emission estimates of 1,1,2-trichlorotrifluorethane (CFC-113) from daily global background observations June 1982-June 1994, J. Geophys. Res., 101, 12585-12599, 1996.

Fraser, P. J., P. Hyson, R. A. Rasmussen, A. J. Crawford, and M. A. K. Khalil, Methane, carbon monoxide and methyl chloroform in the southern hemisphere, J. Atmos. Chem, 4, 3-42, 1986.

Fraser, P. J., D. E. Oram, C. E. Reeves, S. A. Penkett, and A. McCulloch, Southern Hemispheric halon trends (1978-1998) and global halon emissions, J. Geophys. Res., 104, 15985-15999, 1999.

McCulloch, A. and P. M. Midgley, The production and global distribution of emissions of trichloroethene, tetrachloroethene and dichloromethane over the period 1988-1992, Atmospheric Environment, 30, 601-608, 1996.

McCulloch, A., P. M. Midgley, and D. A. Fisher, Distribution of emissions of chlorofluorocarbons (CFCs) 11, 12, 113, 114, and 115 among reporting and non-reporting countries in 1986, Atmospheric Environment, 28, 2567-2582, 1994.

McCulloch, A., M. L. Aucott, T. E. Graedel, G. Kleiman, P. M. Midgley, and Y.-F. Li, Industrial emissions of trichloroethene, tetrachloroethene and dichloromethane: Reactive chlorine emissions inventory, J. Geophys. Res., 104, 8417-8427, 1999.

Midgley, P. M., The production and release to the atmosphere of 1,1,1-trichloroethane (methyl chloroform), Atmospheric Environment, 23, 2663-2665, 1989.

Midgley, P. M.,The production and release to the atmosphere of industrial halocarbons, Ber. Bunsenges. Phys. Chem., 96(3), 293-296, 1992.

Midgley, P. M. and A. McCulloch, The production and global distribution of emissions to the atmosphere of 1,1,1-trichloroethane (methyl chloroform), Atmospheric Environment, 29, 1601-1608, 1995.

Montzka, S. A., J. H. Butler, R. C. Myers, T. M. Thompson, T. H. Swanson, A. D. Clarke, L. T. Lock, and J. W. Elkins, Decline in the tropospheric abundance of halogen from halocarbons:  Implications for stratospheric ozone depletion, Science, 272, 1318-1322, 1996.

Montzka, S. A., J. H. Butler, J. W. Elkins, T. M. Thompson, A. D. Clarke, and L. T. Lock, Present and future trends in the atmospheric burden of ozone-depleting halogens, Nature, 398, 690-694, 1999.

Montzka, S. A., C. M. Spivakovsky, J. H. Butler, J. W. Elkins, L. T. Lock, and D. J. Mondeel, New observational constraints for atmospheric hydroxyl on global and hemispheric scales, Science, in press, 2000.

United Nations Environmental Programme: 1985 Vienna Convention for the Protection of the Ozone Layer; 1987 Montreal Protocol to Reduce Substances that Deplete the Ozone Layer Report, Final Report (New York); 1990 London Amendment; 1992 Copenhagen Amendment; 1997 Production and Consumption of Ozone Depleting Substances, 1986-1995.