H. C. Pumphrey, et al.
Tropical tape recorder observed in HCN
Geophysical Research Letters, 35(5), L05801, 2008; doi: 10.1029/2007GL032137
HCN Middle atmosphere Troposphere Remote sensing HCN tropical stratosphere


[1] The tropical tape recorder is an effect in which a seasonal cycle in the mixing ratio of a gas is imposed on air entering the stratosphere and is then transported upwards by the Brewer-Dobson circulation. We report the observation of this effect in the mixing ratio of HCN, as measured by two satellite instruments: MLS on Aura and ACE-FTS on SCISAT-1. The cycle does not repeat every year; the data so far suggest that the dominant period is about two years. The reason for this periodicity is not yet fully understood. Comparisons with MODIS fire-count data suggest that it may be connected to inter-annual variations in biomass burning in Indonesia and the surrounding region.


  author = "H. C. Pumphrey and C. Boone and K. A. Walker and P. Bernath and N. J. Livesey",
  title = "Tropical tape recorder observed in HCN",
  year = 2008,
  journal = "Geophysical Research Letters",
  volume = 35,
  number = 5,
  pages = "L05801",
  month = "Mar",
  keywords = "HCN, Middle atmosphere, Troposphere, Remote sensing, HCN, tropical, stratosphere",
  doi = "10.1029/2007GL032137",
  url = ""
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