COST 723 kick-off workshop, ESTEC, Nordwijk, Assimilation of space and air borne measurements in a tropospheric chemistry transport model by 4D-var H. Elbern, A. Strunk Rhenish Institute for Environmental Research at the University of Cologne

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt2 Contents Introduction: why 4D-var Assimilation of flight campaign data Assimilation of satellite data

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt3 Design of the case study CTM and adjoint CTM (symmetric operator split): –RADM2 gas phase: 61 species –4th order Bott advection, horiz. & vert. –Implicit diffusion (Thomas algorithm) Grid: 125/54 km horiz. spacing, 100 hPa – large grid: 77 x 67 x 26 (refined tropopause:  z ~1 km) Meteorological fields by MM5 Case studies: – CONTRACE: 14. November 2001 –SPURT: January 2002

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt4 Design of the assimilation experiment assimilation interval 00:00-16:00 UTC( max), optimisation: –SPURT: chemical state variables –CONTRACE: chemical state variables + emission rates isotrop. background error covariance matrix (BECM) L-BFGS (quasi-Newton) minimisation Preconditioning by square root (BECM)

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt5 4D-var configuration Mesoscale EURAD 4D-var data assimilation system meteorological driver MM5 meteorological driver MM5 EURAD emission model EEM emission 1. guess EURAD emission model EEM emission 1. guess direct CTM emission rates Initial values Initial values minimisation adjoint CTM adjoint CTM observations analysis gradient fore- cast

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt6 SPURT SPURT: Trace gas Transport in the Tropopause Region Coord.: A. Engel, Univ Frankfurt Jan a.m. 17. p.m. 17. a.m. 18. p.m. 18. a.m. 19. p.m. 19. Original project objectives: to analyse transport signatures in terms of chemical ages in the mixing region of troposphere and stratosphere However: not suitable for a limited area data assimilation set-up. Hence, find chemical states, correlation length. Find chem state at 00:00 UTC to best match daytime observations UTC 12 assimilation interval

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt7 SPURT SPURT Jan 17, guess assimilation result observations flight height [km] O3O3 CO

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt8 SPURT SPURT Jan 18, guess assimilation resultobservationsflight height [km] am: Canary Isl.  Casablancapm: Casablanca  Hamburg O3O3 CO

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt9 SPURT SPURT Jan 19, 2002 O3O3 CO 1. guess assimilation resultobservationsflight height [km] am: Hamburg  North Capepm: North Cape  Hamburg

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt10 SPURT SPURT Jan 19, 2002

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt11 CONTRACE CONTRACE Convective Transport of Trace Gases into the upper Troposphere over Europe: Budget and Impact of Chemistry Coord.: H. Huntrieser, DLR flight path Nov. 14, 2001

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt12 CONTRACE CONTRACE Nov. 14, 2001, southbound 1. guess assimilation result observations flight height [km] O3O3 H2O2H2O2 CO NO HCHO

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt13 CONTRACE CONTRACE Nov. 14, 2001 north (= home) bound O3O3 H2O2H2O2 CO NO 1. guess assimilation resultobservationsflight height [km]

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt14 Assimilated data types in situ –surface observations –radio sondes –aircraft –tethered balloons Satellites: GOME –tropospheric NO2 columns –tropospheric NN derived ozone profiles (  h=1km)

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt15 Assimilation of GOME NO 2 tropospheric columns, GOME NO 2 columns: Courtesy of A. Richter, IFE, U. Bremen # molec./cm 2 post assimilation forecast started: :00 UTC # molec./cm 2 NOAA ch 3 (near infrared) # molec./cm 2 forecast without assimilation GOME NO 2 columns: Courtesy of A. Richter, IFE, U. Bremen

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt16 GOME ozone profile assimilation ( ) Data: Neuronal Network retrieval (Müller et al., 2003) + NN ozone retrieval

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt17 GOME ozone profile assimilation II ( ) GOME ozone profile assimilation II ( ) Data: Neuronal Network retrieval (Müller et al., 2003) + NN ozone retrieval

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt18 Assimilation of GOME NO 2 tropospheric columns, GOME NO 2 columns: Courtesy of A. Richter, IFE, U. Bremen # molec NO 2 /cm 2 NOAA ch 3 (near infrared) # molec NO 2 /cm 2 post assimilation forecast started: :00 UTC forecast without assimilation

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt19 Conclusions: successful UTLS data assimilation in a mixing regime requires readiness to identify different chemical regimes locally: –strat. intrusions, free troposphere, updrafts problem of first guess with phase shifts (e.g. streamers must be captured correctly) smoother algorithms give qualitative indication on the ability to simulate observations

COST 723 kick-off workshop, ESTEC, Nordwijk, cost04.ppt20 Acknowledgments Data provision –CONTRACE: Dr. H. Huntrieser and project, –SPURT: Dr. C. Schiller and group, ICG-I, FZ Jülich; Dr. H. Fischer and group, MPI-C, Mainz Funding by BMBF ZAM, FZ Jülich for computational facilities