CHEM2D-OPP: A new linearized gas-phase ozone photochemistry parameterization for high-altitude NWP and climate models J. P. McCormack1, S. D. Eckermann1, D. E. Siskind1, and T. J. McGee2 1E. O. Hulburt Center for Space Research, Naval Research Laboratory (NRL), Washington DC, USA 2NASA Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
Abstract. The new CHEM2D-Ozone Photochemistry Parameterization (CHEM2D-OPP) for
high-altitude numerical weather prediction (NWP) systems and climate models
specifies the net ozone photochemical tendency and its sensitivity to
changes in ozone mixing ratio, temperature and overhead ozone column
based on calculations from the CHEM2D interactive middle atmospheric
photochemical transport model.
We evaluate CHEM2D-OPP performance using both short-term (6-day) and long-term (1-year)
stratospheric ozone simulations with the prototype high-altitude
NOGAPS-ALPHA forecast model. An inter-comparison of NOGAPS-ALPHA 6-day ozone hindcasts for
7 February 2005 with ozone photochemistry parameterizations currently used in operational
NWP systems shows that CHEM2D-OPP yields the best overall agreement with
both individual Aura Microwave Limb Sounder ozone profile measurements
and independent hemispheric (10°–90° N) ozone analysis fields.
A 1-year free-running NOGAPS-ALPHA simulation using CHEM2D-OPP
produces a realistic seasonal cycle in zonal mean ozone throughout
the stratosphere. We find that the combination of
a model cold temperature bias at high latitudes in winter and
a warm bias in the CHEM2D-OPP temperature climatology
can degrade the performance of the linearized ozone
photochemistry parameterization over seasonal time scales
despite the fact that the parameterized temperature dependence is weak
in these regions.
Citation: McCormack, J. P., Eckermann, S. D., Siskind, D. E., and McGee, T. J.: CHEM2D-OPP: A new linearized gas-phase ozone photochemistry parameterization for high-altitude NWP and climate models, Atmos. Chem. Phys., 6, 4943-4972, doi:10.5194/acp-6-4943-2006, 2006.