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Validation of TES Methane with HIPPO Observations. For Use in Adjoint Inverse Modeling. Kevin J. Wecht. TES Science Team Meeting. 17 June 2010. Special thanks to: Annmarie Eldering Daniel JacobSteve Wofsy Susan Kulawik Lin ZhangEric Kort - PowerPoint PPT Presentation
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Validation of TES Methane with HIPPO Observations
For Use in Adjoint Inverse Modeling
Kevin J. Wecht17 June 2010TES Science Team Meeting
Special thanks to:Annmarie Eldering Daniel Jacob
Steve WofsySusan Kulawik Lin Zhang
Eric KortGreg Osterman Christopher Pickett-HeapsVivienne Payne
Adjoint Inverse Modeling of Methane Sources
Adjoint inverse analysis
OPTIMIZATION OF SOURCES
GEOS-Chem CTM
ValidationHIPPO
Methane(Wofsy, Kort)
Apriori Sources
GEOS-Chem Adjoint
EDGAR v4, Kaplan, GFED 2, Yevich and Logan [2003]
HIPPO Methane provides:• Large number of profiles• Wide latitudinal coverage• Remote from sources
(reduces collocation error)
TES Methane (Worden, Kulawik)
HIPPOHIPPO I HIPPO II
January 9-30, 2009 October 22 - November 20, 2009
138 vertical profiles 147 vertical profiles
HIAPER Pole-to-Pole Observation Program
• Five missions:- Jan, Nov 2009- April 2010, June & Aug 2011
• > 700 vertical profiles by finish- 80% surface – 330 hPa- 20% surface – < 200 hPa
• Methane Instrument Properties- Frequency: 1 Hz- Accuracy/Precision: 1.0/0.6 ppb
Flight pathVertical Profile
Flight pathVertical Profile
Photos courtesy: S. Wofsy
HIPPO vs. TES by Latitude
RTVM
R [
ppb]
RTVM
R [
ppb]HIPPO I
Jan 9-30,2009
HIPPO IIOct 22 – Nov 20,
2009
TES observation operator is applied to all profiles unless explicitly stated.Positive bias and significant noise, but latitudinal gradient is captured.
TES
HIPPO w/ TES op.HIPPO 250-450 hPa
HIPPO vs. TES by Latitude
RTVM
R [
ppb]
RTVM
R [
ppb]HIPPO I
Jan 9-30,2009
HIPPO IIOct 22 – Nov 20,
2009
HIPPO I: bias = 73.6 ppb, residual error = 41.1 ppb n = 129HIPPO II: bias = 61.0 ppb, residual error = 44.8 ppb n = 147
TES over landTES over ocean
Mean Bias
Distribution of Residual ErrorHIPPO I
Errors are normally distributed, important for derivation of inversion cost function.
HIPPO II also shows Gaussian residual error.
Histograms ofHIPPO – TES difference
All Observations
Land ObservationsOcean Observations
mean = 73.6σ = 41.1n = 129
mean = 78.0σ = 37.3n = 90
mean = 63.7σ = 47.8n = 39
Mean and standard deviation in units [ppb]
Collocation Error
Mean Bias
Quantify observation, representation error. Error and bias differ for HIPPO I and II.
HIPP
O I
HIPP
O II
Residual ErrorTES bias and residual error vs. size of coincidence window
Observation error
[ppb
][p
pb]
Distance [km]125 250 375 500
Distance [km] Distance [km]
40
120
80
0
40
120
80
0
# Observations24 hour12 hour
Model ComparisonTES and GEOS-Chem along HIPPO I flight track
TES and GEOS-Chem averaged over the Pacific during the HIPPO I period
HIPPO IJan 9-30,
2009
RTVM
R [
ppb]
RTVM
R [
ppb]
Consistency with HIPPO
GEOS-Chem w/ TES op.TES
HIPPO w/ TES op.
Model Comparison
RTVM
R [
ppb]
RTVM
R [
ppb]
Consistency with HIPPO
HIPPO IIOct 22 – Nov 20,
2009
TES and GEOS-Chem along HIPPO II flight track
TES and GEOS-Chem averaged over the Pacific during the HIPPO II period
GEOS-Chem w/ TES op.TES
HIPPO w/ TES op.
Model Comparison – NOAA GMD2008 Annual Average
• GEOS-Chem provides good simulation in the annual average• Seasonality to inter-hem. gradient• Missing northern hemisphere sources? Natural gas production?
[ppb]
GEOS-Chem and GMD surface methane
GE
OS
-Che
m [p
pb]
NOAA GMD [ppb]
[ppb
]Latitude
GEOS-Chem is a good platform inter-comparison of data sets such as TES methane.
[ppb
]
GEOS-ChemNOAA GMD
Model Comparison – TES2009 Annual Average
• TES captures variability in GEOS-Chem, with large residual error.• Interpretation of latitudinal profile complicated by latitudinal structure of DOFS • Model overestimate around equator.
Diff
eren
ce
[ppb
]R
TVM
R [
ppb]
GE
OS
-Che
m w
/ TE
S o
pera
tor
RTV
MR
GEOS-ChemGEOS-Chem w/ TES op.TES
Model ComparisonTES RTVMR w/
mean TES – GEOS-Chem difference subtracted
GEOS-Chem RTVMR
[ppb]
Difference: GEOS-Chem – TES
[ppb]
TES a priori RTVMR
Quantitative source attribution of differences requires inverse modeling.
GEOS-ChemGEOS-Chem w/ TES op.TES
Adjoint Inverse Modeling of Methane Sources
Adjoint inverse analysis
OPTIMIZATION OF SOURCES
GEOS-Chem CTM
ValidationHIPPO
Methane(Wofsy, Kort)
Apriori Sources
GEOS-Chem Adjoint
EDGAR v4, Kaplan, GFED 2, Yevich and Logan [2003]
TES Methane (Kulawik, Osterman)
4D-Var assimilation of TES data:• Optimize emissions on
– 2x2.5 horizontal grid– monthly temporal res.
• Evaluate results with HIPPO, NOAA GMD
• Incorporation of additionalsatellite products
Thank You!
• TES captures latitudinal gradient in HIPPO data• TES is biased high but residual instrument error is within self-reported range
– 73.6 ± 41.1 ppb during HIPPO I– 61.0 ± 44.8 ppb during HIPPO II
• Pending prognosis of TES instrument, will validate again with HIPPO IV & V• Enabling Inverse Modeling:
– Time period: TES provides useful information through the end of HIPPO II.– Quantification of bias, observation error, and representation error.– Error normally distributed.– Robust latitudinal gradient with greater coverage than surface stations
• HIPPO and NOAA GMD will be used to evaluate inversion results.• Future incorporation of additional satellite products.