validation of tes methane with hippo observations
DESCRIPTION
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 PresentationTRANSCRIPT
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.