Observations and analysis of polar stratospheric clouds detected by POAM III and SAGE III during the SOLVE II/VINTERSOL campaign in the 2002/2003 Northern Hemisphere winter J. Alfred1, M. Fromm2, R. Bevilacqua2, G. Nedoluha2, A. Strawa3, L. Poole4, and J. Wickert5 1Computational Physics Inc., Springfield VA, USA 2Naval Research Lab, Remote Sensing Division, Washington D.C., USA 3NASA Ames Research Center, Atmospheric Physics Branch, Moffett Field CA, USA 4Science Systems & Applications Inc., Hampton VA, USA 5GeoForschungsZentrum, Dept. Geodesy and Remote Sensing, Potsdam, Germany
Abstract. The Polar Ozone and Aerosol Measurement and Stratospheric Aerosol and Gas
Experiment instruments both observed high numbers of polar stratospheric
clouds (PSCs) in the polar region during the second SAGE Ozone Loss and
Validation (SOLVE II) and Validation of INTERnational Satellites and Study
of Ozone Loss (VINTERSOL) campaign, conducted during the 2002/2003 Northern
Hemisphere winter. Between 15 November 2002 (14 November 2002) and 18 March
2003 (21 March 2003) SAGE (POAM) observed 122 (151) aerosol extinction
profiles containing PSCs. PSCs were observed on an almost daily basis, from
early December through 15 January, in both instruments. No PSCs were
observed from either instrument from 15 January until 4 February, and from
then only sparingly in three periods in mid- and late February and mid-March.
In early December, PSCs were observed in the potential temperature range
from roughly 375 K to 750 K. Throughout December the top of this range
decreases to near 600 K. In February and March, PSC observations were
primarily constrained to potential temperatures below 500 K. The PSC
observation frequency as a function of ambient temperature relative to the
nitric acid-trihydrate saturation point (using a nitric acid profile prior
to denitrification) was used to infer irreversible denitrification. By late
December 38% denitrification was inferred at both the 400–475 K and
475–550 K potential temperature ranges. By early January extensive levels of
denitrification near 80% were inferred at both potential temperature
ranges, and the air remained denitrified at least through early March.
Citation: Alfred, J., Fromm, M., Bevilacqua, R., Nedoluha, G., Strawa, A., Poole, L., and Wickert, J.: Observations and analysis of polar stratospheric clouds detected by POAM III and SAGE III during the SOLVE II/VINTERSOL campaign in the 2002/2003 Northern Hemisphere winter, Atmos. Chem. Phys., 7, 2151-2163, doi:10.5194/acp-7-2151-2007, 2007.