8.3
A cold pool reference frame for analyzing polar stratospheric clouds and tropospheric forcing
Michael D. Fromm, NRL, Washington, DC; and J. M. Alfred
The dominance of synoptic scale tropospheric forcing as a driver for Arctic PSC existence has been established for a single season [Teitelbaum et al., 2001, J. Geophys. Res.] and over the entire SAM II, POAM II, POAM III era [Fromm et al. 2003, J. Geophys. Res.]. Here we analyze POAM III and SAGE III PSC observations in a new geospatial context: the cold pool reference frame (CPRF). Our focal point will be the cold, cloudy December 2002--during the SOLVE II/VINTERSOL campaigns.
We present a CPRF using the canonical nitric acid trihydrate (NAT) saturation isotherm as the boundary, with isotherms for liquid ternary aerosol condensation and the water-ice frost point for inner PSC-composition “latitudes.” The temperature minimum and the longitude of the temperature minimum mark the pole and axis of the CPRF, respectively. The CPRF also incorporates the air flow through the cold pool with the Montgomery stream function. With such information, we relate SAGE and POAM occurrence of PSCs with respect to the cold pool axis and the upwind/downwind PSC-composition latitude belts. The CPRF model, and a justification based on monthly average December 2002 meteorological analyses, is presented. To illustrate, we show the case of 19 December 2002 and monthly PSC results.
Session 8, Stratospheric Ozone and Tropospheric Weather-II
Thursday, 24 January 2008, 11:00 AM-12:15 PM, 230
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