Upper-Air Inter-Comparison Experiment Update Presented By Philippe Peylin on behalf of Christopher...
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Transcript of Upper-Air Inter-Comparison Experiment Update Presented By Philippe Peylin on behalf of Christopher...
Upper-Air Inter-Comparison Experiment
Update
Presented By Philippe Peylin
on behalf of
Christopher Pickett – Heaps &
Peter Rayner
Purpose of the experiment…
An inter-comparison of forward transport using a common CO2 flux field
Use of non-surface CO2 data in the cross-validation of atmospheric CO2 inversion models
• Focus on differences in forward simulations
Methodology…
Single (common) CO2 flux field generated from the
Baker et al. 2006 inter-comparison study
inserted in the ATMs
Model CO2 concentration field sampled appropriately
to compare to available CO2 measurements
Available CO2 measurements…
Non-Surface CO2 Airborne Data Archive : Consists of measurements from 39 aircraft campaigns
• 27 short, intensive campaignsE.G. COBRA 2000, 2003, 2004 (Gerbig et al. 2003, Lin et al. 2006 and others),
PEM-WEST A/B (Anderson et al. 1996, Hoell et al. 1997), PEM-TROPICS A/B (Hoell et al. 1999, Raper et al. 2001), BIBLE A (Machida et al. 2003) ), CRYSTAL (Xueref et al. 2004) and others
• 12 long-term, regular campaignsE.G. Matsueda et al. (1999), NOAA/GMA profile data (Stephens et al. in press),
Cape Grim profile data (Pak 2000, Langenfelds et al. 1996, 1999), CARIBIC (Brenninkmeijer et al. 2005) and others
Available CO2 measurements…
Non-Surface CO2 Airborne Data Archive
• Temporal Coverage: 1987 – 2004• Surface Lower Stratosphere
– Majority of data within the free troposphere
• Reasonable Global Coverage– Data concentrated over the Pacific Ocean and North
America
Altitude Variation (surf - ~21km)
Surf 21,6 km
Inter-comparison project: Current Status…
All participating models required to:
Re-grid flux fields onto respective model grids
Run a forward simulation with analysed meteorology from 1988 – 2003 (or part thereof)• Use of ‘real winds’
Sample the model CO2 conc. field at specified spatio-temporal locations
Inter-comparison project: Current Status…
Currently there are 4 participating ATMs
• LSCE: LMDz (P. Bousquet)
• CSIRO: CCAM (C. Pickett – Heaps & R. Law)
• NIES: CCSR (P. Patra) (Not used yet !)
• JMA: CTDM (T. Maki)
• Colorado State Univ. will hopefully become a future participant
Current results are very preliminary (further analysis planed for this year)
Inter-comparison results to date…
Analysis to date based on profile data:
Cape Grim Profile Data– Monthly vertical profiles over Cape Grim from 1991 – 2000,
surface - ~7000m CAR Profile Data
– Weekly vertical profiles flown over CAR from 1992 – 2002, surface - ~7000m
For each profile…• RMS error and mean model bias (average
residual) are calculated
ANNUAL MEAN (TRANSCOM mean flux)RMS ERROR (ppm) RESIDUALS (ppm)Mean SD Mean SD
CCAM 1.34 0.82 -0.06 1.07LMDz 1.28 0.76 -0.69 0.81CTDM-JMA 1.92 0.98 1.46 1.41
DJF MEAN CCAM 1.03 0.51 -0.05 0.83LMDz 1.11 0.53 -0.76 0.64CTDM-JMA 1.55 0.65 1.22 0.85
MAM MEAN CCAM 1.19 0.71 0.45 0.87LMDz 1.09 0.54 -0.59 0.67CTDM-JMA 2.29 1.01 1.97 1.10
JJA MEAN CCAM 1.76 0.96 0.12 1.34LMDz 1.74 0.9 -0.74 1.18CTDM-JMA 2.39 1.2 1.77 1.45
SON MEAN CCAM 1.32 0.79 -0.68 0.77LMDz 1.11 0.74 -0.65 0.58CTDM-JMA 1.45 0.50 0.94 0.69
CCAMLMDzCTDM
CCAMLMDzCTDM
Inter-comparison Results: RMS error/Model Bias average statistics & time-seriesCAR
Inter-comparison Results: RMS error/Resid seasonality CAR
NOTE: Strong seasonality in RMS error in all forward simulations
RMS vs. Mt
0
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0 2 4 6 8 10 12Mth
RM
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CCAM
LMDz
CTDM
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LMDz
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RMS error vs. Month Bias vs. Month
CCAMLMDzCTDM
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Jan Dec Jan Dec
Inter-comparison Results: Seasonal Mean Residual Profiles CAR
CI: Confidence Interval of mean model bias for different levels of the atmosphere
NOTE: Seasonal errors in the vertical gradient during summer (June – August)
CCAMCI
LMDzCI
CTDMCI
-5
Jun-Jul-AugDec-Jan-Feb
5-4 4
ANNUAL MEAN (TRANSCOM mean flux)RMS ERROR (ppm) RESIDUALS (ppm)Mean SD Mean SD
CCAM 0.63 0.27 -0.06 0.46LMDz 0.38 0.18 -0.13 0.23CTDM-JMA 0.84 0.54 -0.50 0.78
DJF MEAN CCAM 0.55 0.18 -0.13 0.25LMDz 0.38 0.12 -0.08 0.25CTDM-JMA 0.76 0.45 -0.57 0.55
MAM MEAN CCAM 0.76 0.27 -0.49 0.32LMDz 0.26 0.09 -0.04 0.12CTDM-JMA 1.03 0.47 -0.91 0.52
JJA MEAN CCAM 0.63 0.33 -0.01 0.49LMDz 0.47 0.25 -0.19 0.28CTDM-JMA 1.01 0.77 -0.66 0.95
SON MEAN CCAM 0.62 0.28 0.26 0.44LMDz 0.38 0.19 -0.19 0.20CTDM-JMA 0.67 0.39 -0.04 0.70
Inter-comparison Results: RMS error/Model Bias average statistics & time-seriesCAPE GRIM
CCAMLMDzCTDM
CCAMLMDzCTDM
Inter-comparison Results: RMS error/Resid seasonality Cape Grim
NOTE: Strong seasonality in model bias within CCAM/CTDM fwd simul. but reduced seasonality in the LMDz fwd simul.
-3
-2.5
-2
-1.5
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Pro
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CCAM
LMDz
CTDM
Bias vs. MonthRMS error vs. Month
CCAMLMDzCTDM
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Jan Dec Jan Dec
Inter-comparison Results: Seasonal Mean Residual Profiles Cape Grim
CCAMCI
LMDzCI
CTDMCI
Jun-Jul-Aug
Dec-Jan-Feb Mar-Apr-Mai
Sep-Oct-Nov
Inter-comparison Results: Variation across four modelsNon-Surface CO2 Airborne Data Archive (VERY PRELIMINARY(VERY PRELIMINARY!)
RANGE: 0.05ppm – >1.7ppm (9,000m – 12,000m)
RANGE: 0.04ppm – >2ppm (6000m – 9000m)
Future Plans…
Solve current problems in sampling conc. field with certain ATMs• Inclusion of results from more models
Extend inter-comparison to the entire upper-air archive
Perform extensive analysis of the Non-Surface CO2 Airborne Data Archive
• Statistical/Climatological analysis
THANKS TO:
The LSCE & CMAR• Dr Peter Rayner, Dr Rachel Law, Dr
Philippe Ciais, Dr Philippe Bousquet & Dr Philippe Peylin
All inter-comparison participants All measurement campaign PIs who have
contributed to the data archive
AND… sincere apologies that I am not able to attend the TRANSCOM meeting this year