Tropospheric ozone layers observed during PEM-Tropics B


  • Valérie Thouret,

  • John Y. N. Cho,

  • Mathew J. Evans,

  • Reginald E. Newell,

  • Melody A. Avery,

  • John D. W. Barrick,

  • Glen W. Sachse,

  • Gerald L. Gregory


In this paper we analyze distinct layers seen in the tropospheric ozone and water vapor profiles taken during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission in the Tropical Pacific (PEM-Tropics) Phase B campaign. In summary, fewer layers were observed in this campaign than during the PEM-Tropics A campaign. However, of those layers found, there were relatively more ozone-rich-water-vapor-poor layers (68% versus 52%). The percentage of the sampled troposphere occupied by layers during PEM-Tropics B was less than half of that found during PEM-Tropics A (8% versus 20%). The differences between these two campaigns suggest a seasonal variation in the occurrence of layers. This is confirmed using measurements made by the Southern Hemisphere Additional Ozonesondes (SHADOZ) network.