Institut für Physik der Atmosphäre Institut für Physik der Atmosphäre Climate-Chemistry Interactions - User Requirements Martin Dameris DLR-Institut für Physik der Atmosphäre Oberpfaffenhofen

Institut für Physik der Atmosphäre Modelling of climate-chemistry interactions - Why? Climate change detected (e.g. IPCC, 2001). Changes in atmospheric composition observed (e.g. WMO, 2003). Coupling of chemical processes in climate models. Climate-Chemistry Models (CCMs) have been employed to examine the feedback between dynamical, physical and chemical processes.

Institut für Physik der Atmosphäre Modelling of climate-chemistry interactions - Why? The primary goals of CCMs are to support analyses of (long-term) observations of trace gases and aerosols, evaluate emission control measures, determine and quantify underlying dynamical, physical and chemical processes, and their feedback, explain recent changes (variability), assess possible future trends.

Institut für Physik der Atmosphäre Modelling of climate-chemistry interactions - scientific applications or problems Tropospheric air quality (chemical weather). The effect of surface pollution (including traffic), aviation and natural factors on chemical, radiative and dynamical (e.g. long-range transport) processes in the upper troposphere and stratosphere. How do climate change impact atmospheric chemistry (composition) and vice versa? A key science issue is to determine the timing of ozone recovery and future ultraviolet radiation at the surface.

Institut für Physik der Atmosphäre Development of CCMs - general progress in recent years about 15 years ago first coupling of climate models (GCMs) to simplified chemistry (e.g. Cariolle et al., 1990). about 7 years ago off-line climate-chemistry models (CCMs) with complex chemistry (e.g. Steil et al., 1998); first results regarding ozone recovery (e.g. Dameris et al.,1998; Shindell et al., 1998). today interactively coupled CCMs available (e.g. Hein et al., 2001); investigations of feedback between dynamical, physical, and chemical processes (e.g. Schnadt et al., 2002; Austin et al., 2003).

Institut für Physik der Atmosphäre The CCM E39/C - Description of model system Surface, aircraft, lightning NO x Emissions [Tg N/a] Radiation Long-wave Short-wave Chemical Boundary Conditions Atmosphere: CFCs, at 10 hPa: ClX, NO y, Surface: CH 4, CO Chemistry (CHEM) Methane oxidation Heterogeneous Cl reactions PSC I, II, aerosols Dry/wet deposition Photolysis Feedback O 3, H 2 O, CH 4, N 2 O, CFCs Prognostic variables (vorticity, divergence, temperature, specific humidity, log-surface pressure, cloud water), hydrological cycle, diffusion, gravity wave drag, transport of tracers, soil model, boundary layer; sea surface temperatures. T30, 39 layers, top layer centred at 10 hPa Dynamics (ECHAM) Hein et al., 2001

Institut für Physik der Atmosphäre Application of CCMs for process studies Investigation of chemical composition and climate variability (change), tropospheric and stratospheric coupling, especially in order to determine and quantify feedback processes.

Institut für Physik der Atmosphäre Comparison - E39/C vs. MSU: temperature anomalies ( ), km, global mean

Institut für Physik der Atmosphäre Comparison - E39/C vs. NCEP analysis: zonal mean temperature (80°N, 30 hPa) NCEP E39/C Type I PSC Type II PSC Hein et al., 2001 E19/C Type I PSC

Institut für Physik der Atmosphäre Comparison - E39/C vs. NCEP analysis: zonal mean wind (60°N, 30 hPa) E39/C NCEP Hein et al., 2001 E19/C

Institut für Physik der Atmosphäre Comparison - E39/C vs. GOME: ozone columns [in DU] Gome data provided by DLR-DFD, Dr. M. Bittner

Institut für Physik der Atmosphäre Comparison - E39/C vs. ground based and TOMS-data: climatological mean values of total ozone and trends Model Observations Hein et al., 2001; Schnadt et al., 2002 Latitude McPeters et al.,

Institut für Physik der Atmosphäre Comparison - E39/C vs. GOME: NO 2 tropospheric columns (July) E39/C (1990) GOME ( ) Lauer et al., 2001; GOME-data provided by IUP, A. Richter and J. Burrows

Institut für Physik der Atmosphäre Comparison - E39/C vs. GOME: NO 2 tropospheric columns, annual cycle over Africa Lauer et al., 2001; Matthes, 2003 ECHAM4/CHEM ECHAM4/CBM (G.-J. Roelofs, Utrecht) GOME

Institut für Physik der Atmosphäre Comparison - E39/C vs. GOME: NO 2 tropospheric columns, annual cycle over Africa and Europe Lauer et al., 2001; Matthes, 2003 ECHAM4/CHEM ECHAM4/CBM (G.-J. Roelofs, Utrecht) GOME

Institut für Physik der Atmosphäre Application of CCMs for sensitivity studies E.g., assessments of future chemical composition, climate change, feedback processes in the lower stratosphere, in particular with respect to ozone.

Institut für Physik der Atmosphäre E39/C - predictions Southern / Northern Hemisphere spring time adapted from Schnadt et al., 2002

Institut für Physik der Atmosphäre E39/C and others - predictions Austin, Schnadt, Dameris, et al., 2003 SH: ozone recovery expected to begin within the range 2001 to 2008 TOMSE39/C NH: ozone recovery expected to begin within the range 2004 to 2019

Institut für Physik der Atmosphäre Evaluation of CCMs - user requirements Satellite data products are required for validation of CCMs! Global coverage (hor. resolution: 50*50 km 2 ). Long-term observation of spatial-temporal variability (inter- annual, seasonal, diurnal) of dynamical, physical and chemical parameters, in particular temperature, wind, cloud cover, H 2 O, CH 4, O 3, CO, OH, NO x, HNO 3,N 2 O, aerosol microphysics. Profiles (vert. resolution: 1 km; troposphere: at least 2-3 independent pieces of height resolved information, with one point in the boundary layer). Temporally high-resolution sampling (troposphere: 60 min.; stratosphere: 3 hours).

Institut für Physik der Atmosphäre Evaluation of CCMs - user requirements Geostationary platforms are required! (3-5 missions necessary to get global coverage)

Institut für Physik der Atmosphäre The End. Thank you!