Inter-comparison of 11-year solar cycle response in mesospheric ozone and temperature obtained by HALOE satellite data and HAMMONIA model

Abstract

To investigate the effects of decadal solar variability on ozone and temperature in the MLT region, data obtained from the Halogen Occultation Experiment (HALOE) aboard Upper Atmospheric Research Satellite (UARS) during the period 1992-2004 are analyzed using a multifunctional regression model. The experimental results are compared with results from the 3-D chemistry climate model HAMMONIA (Hamburg Model of Neutral and Ionized Components). The simulated and observed responses of temperature and ozone profiles to the 11-year solar cycle show many similarities. The inferred annual-mean solar signal in ozone is found to be insignificant in the lower mesosphere whereas it is of the order of 5%/100 sfu (solar flux units; units of 10.7 cm radio flux) in the upper mesosphere for both low and mid latitudes. Results indicate a hemispheric symmetry in the tropics but not at midlatitudes for the ozone response. The inferred annual mean temperature response is found to be of the order of 0.5-1 K/100 sfu. There is better agreement between the HALOE derived and model simulated responses in the tropics than at midlatitudes, both in temperature and ozone. Results obtained in the present study are also compared with the results obtained by other models.