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Long-range transport of ozone from the Los Angeles Basin: A case study. A.O. Langford 1 , C. J. Senff 2 , R.J Alvarez 1 II, R. M. Banta 1 , R.M. Hardesty 1 1 Chemical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA
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Long-range transport of ozone from the Los Angeles Basin: A case study A.O. Langford1, C. J. Senff2, R.J Alvarez1 II, R. M. Banta1, R.M. Hardesty1 1Chemical Sciences Division,Earth System Research Laboratory, NOAA, Boulder, Colorado, USA 2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, and Chemical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA
Pre-CalNex flights coincided with highest ozone in SCAB during all of 2009 27 of 31 days in July exceeded NAAQS in South Coast Air Basin
2009 High ozone episode18 July: 1-hr 150 ppbv 8-hr 128 ppbv* * 2009 high value
UCLA SMOG ModelLu, Turco, and Jacobson 1994-1996 Integrated model with: • Mesoscale meteorology • Boundary layer physics • Tracer advection • Convection and diffusion • Photochemistry • Aerosol microphysics and chemistry • Solar and terrestrial radiative transfer
UCLA SMOG ModelLu, Turco, and Jacobson 1994-1996 • 85 x 55 grid cell meteorological domain • 51 x 31 grid cell tracer chemistry domain • Horizontal resolution ~0.05° (~5 km) • 20 non-uniform vertical layers
Synoptic Background 00 UT 18 July 2009 00 UT 27 August 1987 1000 hPa
Synoptic Background 00 UT 18 July 2009 00 UT 27 August 1987 700 hPa
Where does the ozone go?48 h HYSPLIT forward trajectories 24 hours later
Where does the ozone go?48 h HYSPLIT forward trajectories 48 hours later
How often does this occur? What about 19 July 2009
Synoptic Background 00 UT 18 July 2009 00 UT 20 July 2009 1000 hPa
Synoptic Background 00 UT 18 July 2009 00 UT 20 July 2009 700 hPa
Questions for CalNex • What conditions are needed for “Mountain Chimney Effect”? • What conditions favor long range transport from the Los Angeles Basin? • How well can WRF/Chem reproduce these observations?