Impacts of the January 2005 solar particle event on noctilucent clouds and water at the polar summer mesopause 1Institut für Umweltphysik, Universität Bremen, Bremen, Germany
28 Jun 2012
2Fachbereich Physik, Universität Osnabrück, Osnabrück, Germany
3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA
4Instituto de Astrofísica de Andalucía – CSIC, Granada, Spain
Received: 13 Dec 2011 – Published in Atmos. Chem. Phys. Discuss.: 12 Jan 2012 Abstract. The response of noctilucent clouds to the solar particle event in January
2005 is investigated by means of icy particle and ion chemistry simulations.
It is shown that the decreasing occurrence rate of noctilucent clouds derived
from measurements of the SCIAMACHY/Envisat instrument can be reproduced by
one-dimensional model simulations if temperature data from the MLS/Aura
instrument are used.
The model calculations indicate that the sublimation of noctilucent clouds leads to
significant changes of the water distribution in the mesopause region.
These model results are compared with H2O measurements from the
MLS and the MIPAS/Envisat satellite instruments.
The pronounced modelled water enhancement below the icy particle layer
and its decrease during the SPE are not observed by the satellite instruments.
At altitudes >85 km the satellite measurements show an increase
of H2O during the SPE in qualitative agreement with the model predictions.
The discrepancies between model H2O and observations at lower altitudes
be attributed to the one-dimensional model approach which
in particular neglects inhomogeneities and horizontal transport processes.
is revealed that the water depletion due to reactions of proton hydrates
during the considered solar particle event has only a minor impact on the icy
Revised: 26 Jun 2012 – Accepted: 26 Jun 2012 – Published: 28 Jun 2012
Citation: Winkler, H., von Savigny, C., Burrows, J. P., Wissing, J. M., Schwartz, M. J., Lambert, A., and García-Comas, M.: Impacts of the January 2005 solar particle event on noctilucent clouds and water at the polar summer mesopause, Atmos. Chem. Phys., 12, 5633-5646, doi:10.5194/acp-12-5633-2012, 2012.