Tuesday, 13 January 2004
Prognostic ozone in NOGAPS
Room 4AB
The current operational Navy Operational Global Atmospheric
Prediction System (NOGAPS) forecast model uses a zonal mean ozone
climatology to assess the radiative effects of ozone in the
troposphere and stratosphere. Evaluation is underway of
a new prognostic ozone field in a high-altitude (top at 0.005 mb)
test version of NOGAPS. Initialized with offline assimilated data,
the ozone is passively advected using the model's spectral transport
scheme. Results are shown for a case study in September 2002, when
anomalously large planetary-scale wave forcing in the upper
troposphere caused the splitting of the Antarctic polar vortex.
The NOGAPS ozone forecast compares favorably with satellite
measurements from the Total Ozone Mapping Spectrometer (TOMS)
and with offline assimilated ozone fields. The radiative effects
of using the advected ozone rather than the ozone climatology are
addressed by examining the forecast temperatures and offline
radiation calculations. Plans for introducing parameterized
ozone photochemistry into the model are discussed as well as
plans for future assimilation of satellite ozone observations.
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