2003 Antarctic Match campaign

1
Comparison of Observations During the First
Antarctic Match Campaign with a 3D CTM W. Feng1,
M.P. Chipperfield1 School of Earth and
Environment, University of Leeds, UK

• 2003 Antarctic Match campaign
• June-Oct 2003
• nine Ozonesonde stations
• Measure Chemical O3 loss rate
• SLIMCAT 3D CTM
• Ozone and loss rate comparison
• Correction factors

Acknowledgments H.K. Roscoe2, M. Rex3, P. von
der Gathen3, M. Streibel3, F.Goutail4, G.
Konig-Langlo3, T. Deshler5, B. Johnson6, J.
Easson7, M. Yela8, P. Taalas9, K. Sato10
Supported by NERC and SCOUT-O3 project
2
SLIMCAT/TOMCAT 3D CTM

• Off-line chemical transport model Chipperfield,
  JGR, 1999
• Extends to surface using hybrid ?-? levels
  (SLIMCAT version). Variable horizontal/vertical
  resolution.
• Horizontal winds and temperatures from analyses
  (e.g. UKMO, ECMWF (ERA-40 or operational)).
• Vertical motion from diagnosed heating rates or
  divergence.
• Tropospheric physics convection, PBL mixing
  etc.
• Chemistry Full stratospheric chemistry scheme
  (41 species, 160 reactions) with heterogeneous
  chemistry on liquid/solid aerosols/PSCs and an
  equilibrium denitrification scheme.
• NAT-based denitrification scheme included.
• http//www.env.leeds.ac.
  uk/slimcat

3
Arctic Ozone loss versus VPSC
New T42 run
Obs
New T15 run
Old T15 run
Chipperfield M.P., W. Feng and M. Rex(GRL, 2005)
SLIMCAT now gives a realistic representation of
ozone and inferred ozone loss for Arctic winters
under different meteorological conditions
4
Comparison with Observation
425K
460K
495K
Good agreement between Ozonesondes measurements
and SLIMCAT
5
Ozone loss rate at 450K
Match
SLIMCAT
CLAMS
FMI
Models reproduce the observed O3 loss rate very
well
Reprobus
6
The Mean and correction factors
Correction factors
Mean ratio

• SLIMCAT is very consistence with observations
  between 400-650K but gives too much O3 below 400K
• SLIMCAT can be used as a transfer standard to
  expose systematic differences between
  observations from the different ozonesonde sites
  and can provide corrections between them.