Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Volume 13, issue 21
Atmos. Chem. Phys., 13, 10633–10644, 2013
https://doi.org/10.5194/acp-13-10633-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 13, 10633–10644, 2013
https://doi.org/10.5194/acp-13-10633-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 04 Nov 2013

Research article | 04 Nov 2013

The variability of methane, nitrous oxide and sulfur hexafluoride in Northeast India

A. L. Ganesan1, A. Chatterjee2, R. G. Prinn1, C. M. Harth3, P. K. Salameh3, A. J. Manning4, B. D. Hall5, J. Mühle3, L. K. Meredith1, R. F. Weiss3, S. O'Doherty6, and D. Young6 A. L. Ganesan et al.
  • 1Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
  • 2Environmental Sciences Section, Bose Institute, Kolkata, India
  • 3Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
  • 4Atmospheric Dispersion Group, Met Office, Exeter, UK
  • 5NOAA Earth System Research Laboratory, Boulder, Colorado, USA
  • 6Atmospheric Chemistry Research Group, University of Bristol, Bristol, UK

Abstract. High-frequency atmospheric measurements of methane (CH4), nitrous oxide (N2O) and sulfur hexafluoride (SF6) from Darjeeling, India are presented from December 2011 (CH4)/March 2012 (N2O and SF6) through February 2013. These measurements were made on a gas chromatograph equipped with a flame ionization detector and electron capture detector, and were calibrated on the Tohoku University, the Scripps Institution of Oceanography (SIO)-98 and SIO-2005 scales for CH4, N2O and SF6, respectively. The observations show large variability and frequent pollution events in CH4 and N2O mole fractions, suggesting significant sources in the regions sampled by Darjeeling throughout the year. By contrast, SF6 mole fractions show little variability and only occasional pollution episodes, likely due to weak sources in the region. Simulations using the Numerical Atmospheric dispersion Modelling Environment (NAME) particle dispersion model suggest that many of the enhancements in the three gases result from the transport of pollutants from the densely populated Indo-Gangetic Plains of India to Darjeeling. The meteorology of the region varies considerably throughout the year from Himalayan flows in the winter to the strong south Asian summer monsoon. The model is consistent in simulating a diurnal cycle in CH4 and N2O mole fractions that is present during the winter but absent in the summer and suggests that the signals measured at Darjeeling are dominated by large-scale (~100 km) flows rather than local (<10 km) flows.

Publications Copernicus
Download
Citation