Observations of the 2-day wave in UARS MLS temperature and ozone measurements

Mesospheric ozone and temperature data obtained by the Microwave Limb Sound er (MLS) on board the Upper Atmosphere Research Satellite (UARS) have been analyzed to elucidate quasi-two day wave activity. Data from January 1993 w ere analyzed to investigate the evolution and structure of the two day wave . During this period, the wave amplitude in ozone attained its maximum valu e in late January near 30 degrees in the summer hemisphere. The evolution o f the wave amplitude indicates a shift of the peak amplitude to higher lati tudes with increasing height. Correlation of the two day wave phase observe d in MLS ozone and temperature measurements indicates that the perturbation s are out of phase. During the same period, the amplitudes of the perturbat ions in temperature and ozone were positively correlated. The results sugge st that the variations in ozone are photochemically driven in the mesospher e region via changes in reaction rates that are strongly temperature depend ent.