Mass fluxes of O3, CH4, N2O and CF2Cl2 in the lower stratosphere calculated from observational data


  • Andrew Gettelman,

  • James R. Holton,

  • Karen H. Rosenlof


Trace gas mixing ratio data from the Upper Atmosphere Research Satellite (UARS) are combined with a radiatively derived transformed Eulerian mean (TEM) stream function to estimate the net ozone (O3) mass flux from the stratosphere to the troposphere and to investigate the net fluxes of methane (CH4), nitrous oxide (N2O), and CFC-12 (CF2Cl2) into the lower stratosphere. The mass fluxes of ozone and long-lived tracers such as nitrous oxide, methane, and CFC-12 in the lower stratosphere can be estimated from data obtained by the cryogenic limb array etalon spectrometer (CLAES), the microwave limb sounder (MLS) for ozone, and the Halogen Occultation Experiment (HALOE) for ozone and methane. The flux of ozone from the stratosphere to the troposphere is estimated to be 510 Tg of ozone per year with a range of 450 to 590 Tg O3/yr. Net fluxes into the stratosphere are estimated as 27 Tg of methane per year, 8 Tg/yr of N in nitrous oxide, and 0.08 Tg/yr of CF2Cl2. There is good agreement with previous estimates within the range of uncertainty of these calculations.