Transcript Chemistry-Climate Interactions: user requirements

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?
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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.
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Physik der Atmosphäre
Modelling of climate-chemistry interactions - Why?
The primary goals of CCMs are to
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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.
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Physik der Atmosphäre
Modelling of climate-chemistry interactions scientific applications or problems
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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.
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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).
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The CCM E39/C - Description of model system
NOx Emissions [Tg N/a]
Surface, aircraft, lightning
Photolysis
Dynamics (ECHAM)
T30, 39 layers, top layer centred at 10 hPa
Chemistry (CHEM)
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.
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Methane oxidation
Heterogeneous Cl reactions
PSC I, II, aerosols
Dry/wet deposition
Radiation
Chemical Boundary Conditions
Long-wave
Short-wave
Atmosphere: CFCs, at 10 hPa: ClX, NOy,
Surface: CH4, CO
Hein et al., 2001
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.
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Comparison - E39/C vs. MSU:
temperature anomalies (1979-1990), 13-21 km, global mean
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Comparison - E39/C vs. NCEP analysis:
zonal mean temperature (80°N, 30 hPa)
NCEP
E39/C
Type I PSC
Type II PSC
E19/C
Type I PSC
Hein et al., 2001
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Physik der Atmosphäre
Comparison - E39/C vs. NCEP analysis:
zonal mean wind (60°N, 30 hPa)
E39/C
NCEP
E19/C
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Physik der Atmosphäre
Hein et al., 2001
Comparison - E39/C vs. GOME:
ozone columns [in DU]
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Gome data provided by DLR-DFD, Dr. M. Bittner
Comparison - E39/C vs. ground based and TOMS-data:
climatological mean values of total ozone and “trends”
1990
1990 - 1980
Latitude
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-26
-6
-24
McPeters et al., 1996
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Physik der Atmosphäre
Hein et al., 2001; Schnadt et al., 2002
Comparison - E39/C vs. GOME:
NO2 tropospheric columns (July)
E39/C (1990)
GOME (1996 - 2000)
Lauer et al., 2001;
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Physik der Atmosphäre
GOME-data provided by IUP, A. Richter and J. Burrows
Comparison - E39/C vs. GOME: NO2 tropospheric columns,
annual cycle over Africa
ECHAM4/CHEM
ECHAM4/CBM (G.-J. Roelofs, Utrecht)
GOME
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Physik der Atmosphäre
Lauer et al., 2001;
Matthes, 2003
Comparison - E39/C vs. GOME: NO2 tropospheric columns,
annual cycle over Africa and Europe
ECHAM4/CHEM
ECHAM4/CBM (G.-J. Roelofs, Utrecht)
GOME
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Lauer et al., 2001;
Matthes, 2003
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.
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E39/C - predictions
Southern / Northern Hemisphere spring time
1990
2015
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adapted from Schnadt et al., 2002
E39/C and others - predictions
SH: ozone recovery expected
to begin within the range
2001 to 2008
NH: ozone recovery expected
to begin within the range
2004 to 2019
TOMS
E39/C
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Physik der Atmosphäre
Austin, Schnadt, Dameris, et al., 2003
Evaluation of CCMs - user requirements
Satellite data products are required for validation of CCMs!
 Global coverage (hor. resolution: 50*50 km2).
 Long-term observation of spatial-temporal variability (interannual, seasonal, diurnal) of dynamical, physical and chemical
parameters, in particular temperature, wind, cloud cover, H2O,
CH4, O3, CO, OH, NOx, HNO3,N2O, 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).
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Physik der Atmosphäre
Evaluation of CCMs - user requirements
Geostationary platforms are required!
(3-5 missions necessary to get global coverage)
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Physik der Atmosphäre
The End.
Thank you!
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Physik der Atmosphäre