EQUATORIAL KELVIN WAVES AND CORRESPONDING TRACER OSCILLATIONS IN THE LOWER STRATOSPHERE AS SEEN IN LIMS DATA

We have analyzed data from the Limb Infrared Monitor of the Stratosphe re (LIMS) instrument on board the Nimbus 7 to investigate equatorial K elvin waves and dynamically wave-induced variations in the tracer fiel ds such as ozone and water vapor in the lower stratosphere. Temperatur e anomalies of zonal wavenumber one, progressing eastward and having a period of 12-15 days, are clearly observed below 7 hPa for April and May 1979. Vertical phase structure with a wavelength of about 15 km pr ogresses downward in the zonal flow being about -16 ms(-1) averaged fr om 50 to 10 hPa. At the same time; disturbances in the ozone field due to the Kelvin waves are observed: the amplitude is maximum at 30 hPa where vertical gradient of zonal mean ozone is largest and the longitu dinal structure is in-phase with that of temperature. These features a re in good agreement with linear Kelvin wave theory. In the water vapo r field, at 50 hPa, we have also detected wavenumber one eastward prog ressing waves being in-phase with temperature though the spatial struc ture is not as clear as in the ozone field.