Transcript AIM Combining Surface, Aircraft & Satellite Measurements

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 crossvalidation 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 campaigns
E.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 campaigns
E.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
Inter-comparison Results: RMS error/Model Bias average
statistics & time-series
CAR
ANNUAL MEAN (TRANSCOM mean flux)
RMS ERROR (ppm)
Mean
SD
CCAM
LMDz
CTDM-JMA
RESIDUALS (ppm)
CCAM
CCAM
Mean
SD
LMDz
1.34
1.28
1.92
0.82
0.76
0.98
-0.06
-0.69
1.46
CCAM
LMDz
CTDM-JMA
1.03
1.11
1.55
0.51
0.53
0.65
-0.05
-0.76
1.22
0.83
0.64
0.85
MAM MEAN CCAM
LMDz
CTDM-JMA
1.19
1.09
2.29
0.71
0.54
1.01
0.45
-0.59
1.97
0.87
0.67
1.10
JJA MEAN
CCAM
LMDz
CTDM-JMA
1.76
1.74
2.39
0.96
0.9
1.2
0.12
-0.74
1.77
1.34
1.18
1.45
SON MEAN CCAM
LMDz
CTDM-JMA
1.32
1.11
1.45
0.79
0.74
0.50
-0.68
-0.65
0.94
0.77
0.58
0.69
DJF MEAN
1.07 LMDz
CTDM
0.81
CTDM
1.41
Inter-comparison Results: RMS error/Resid seasonality
CAR
6
CCAM
6
LMDz
CTDM
6
6
RMS vs. Mt
CCAM
LMDz
CTDM
5
4
4
2
Prof. mean resid
RMS
3
0
3
2
0
0
2
4
6
8
10
12
-2
1
0
CCAM
LMDz
CDTM
-4
0
0
Jan
2
4
6 Mth
8
10
Dec
RMS error vs. Month
12
-6
-6
Jan
Mth
Bias vs. Month
 NOTE: Strong seasonality in RMS error in
all forward simulations
Dec
Inter-comparison Results: Seasonal Mean Residual Profiles
CAR
Dec-Jan-Feb
Jun-Jul-Aug
CCAM
CI
LMDz
CI
CTDM
CI
-4
4
-5
CI: Confidence Interval of mean model bias for
different levels of the atmosphere
 NOTE: Seasonal errors in the vertical
gradient during summer (June – August)
5
Inter-comparison Results: RMS error/Model Bias average
statistics & time-series
CAPE GRIM
ANNUAL MEAN (TRANSCOM mean flux)
RMS ERROR (ppm)
Mean
SD
CCAM
LMDz
CTDM-JMA
RESIDUALS (ppm)
CCAM
Mean
SD
LMDz
0.46
CTDM
0.23
0.78
0.63
0.38
0.84
0.27
0.18
0.54
-0.06
-0.13
-0.50
DJF MEAN CCAM
LMDz
CTDM-JMA
0.55
0.38
0.76
0.18
0.12
0.45
-0.13
-0.08
-0.57
0.25
0.25
0.55
MAM MEAN CCAM
LMDz
CTDM-JMA
0.76
0.26
1.03
0.27
0.09
0.47
-0.49
-0.04
-0.91
0.32
0.12
0.52
JJA MEAN
CCAM
LMDz
CTDM-JMA
0.63
0.47
1.01
0.33
0.25
0.77
-0.01
-0.19
-0.66
0.49CCAM
0.28
LMDz
0.95
SON MEAN CCAM
LMDz
CTDM-JMA
0.62
0.38
0.67
0.28
0.19
0.39
0.26
-0.19
-0.04
0.44
0.20
0.70
CTDM
Inter-comparison Results: RMS error/Resid seasonality
Cape Grim
CCAM
LMDz
CTDM
3
1.5
3
CCAM
LMDz
CTDM
2.5
CCAM
LMDz
CTDM
1
0.5
0
0
Prof. resid
Profile RMS
2
0
2
4
6
8
10
12
-0.5
1.5
1.5
1
-1
-1.5
-2
0.5
-2.5
0
0
0
Jan
2
4
6
Mth
8
10
Dec
RMS error vs. Month
12
-3
-3
Mth
Jan
Bias vs. Month
 NOTE: Strong seasonality in model bias within
CCAM/CTDM fwd simul. but reduced seasonality
in the LMDz fwd simul.
Dec
Inter-comparison Results: Seasonal Mean Residual Profiles
Cape Grim
Mar-Apr-Mai
Dec-Jan-Feb
CCAM
CI
LMDz
CI
CTDM
CI
Jun-Jul-Aug
Sep-Oct-Nov
Inter-comparison Results: Variation across four models
Non-Surface CO2 Airborne Data Archive (VERY PRELIMINARY!)
RANGE: 0.04ppm – >2ppm (6000m – 9000m)
RANGE: 0.05ppm – >1.7ppm (9,000m – 12,000m)
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 NonSurface 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