saber h 2 o retrieval: current status and future plans
DESCRIPTION
SABER H 2 O RETRIEVAL: CURRENT STATUS AND FUTURE PLANS. A.G. Feofilov 1,2 , A.A. Kutepov 1,2 , W.D. Pesnell 1 , R.A. Goldberg 1. 1 - NASA GSFC, Greenbelt, MD 2 – Catholic University of America, Washington, DC. SABER Team Meeting, June 15,16, 2009, Hampton, VA. Outline. H 2 O non-LTE model - PowerPoint PPT PresentationTRANSCRIPT
SABER H2O RETRIEVAL: CURRENT STATUS AND FUTURE PLANS
A.G. Feofilov1,2, A.A. Kutepov1,2,
W.D. Pesnell1, R.A. Goldberg1
SABER Team Meeting, June 15,16, 2009, Hampton, VA
1 - NASA GSFC, Greenbelt, MD2 – Catholic University of America, Washington, DC
Outline
• H2O non-LTE model
• Sensitivity study
• New validation approach
• Obstacles: “up-down” differences in radiance and temperature profiles
• Updated non-LTE model
• H2O VMR retrievals
• Conclusions and future plans
Non-LTE model of H2O
radiative transitionsV-V, V-T processes
O1D
Oxygen photochemical scheme
[Yankovsky & Manuilova, 2006]
Quantum yield of O2(X,v=1) production per one act of O3 photodissociation
H2O radiance in 6.3µm band: LTE and NLTE
Non-LTE
LTE
Best case scenario
H2O non-LTE model Pressure, temperature,VMRs of other constituents
6.6 m radiance
Retrieved H2O VMR
Real life
H2O non-LTE model Sensitivity study
Comparisons with correlative H2O dataset
6.6 m radiance
Set of parameters to be validated
Retrieved H2O VMR
Updated H2O non-LTE model
Pressure, temperature,VMRs of atmospheric gases
Validation,correction
Validation,correction
Sensitivity study
• V-T rates• V-V rates• Net quantum yield for O2(X,v=1) pumping from O3 photolysis• Temperature
• 5 test atmospheres (polar/midlatitude summer/winter + tropics)• Varying the single rate, comparing the population of H2O(010) to its reference value• Selecting the most important rates and processes
Sensitivity study for midlatitude winter case
Ready for non-LTE model validation?
• Three most important V-V and V-T rates: OK
• Updated quantum yield for O2(X,v=1) production: OK
• Radiances, temperatures, other gases: ???
“Up-down” differences in radiance and temperature
Only downward scans were selected
Validating the H2O non-LTE model
Selecting the correlative H2O dataset (ACE-FTS)
Finding the simultaneous common volume measurements
Using the ACE-FTS H2O VMRin forward radiance calculation
with different sets of non-LTE model parameters63 variants x 40 test atmospheres = 2520 runs
Comparing the calculated SABERradiance with measured radiance
Selecting the set that provide the minimal deviation of radiance
in 60-85km altitude range
Updating the H2O non-LTE model
Minimum 2 corresponds to:
kV-V{H2O-O2}=1.2 x 10-12 cm3s-1
kV-T{O2-O}=3.3 x 10-12 cm3s-1
kV-T{H2O-M}=1.4 x current rates
This is our updated H2O model.It might change after T,P, and radiances are corrected.
Retrievals with updated non-LTE model
Comparisons in numbers
MLS, HALOE, and WVMS at Lauder (45°S) and Mauna Loa (19.5°N)
Microwave monitoring systemat ALOMAR (69.2°N)
Conclusions
• The methodology for non-LTE model validationhas been developed.
• Gain switching effects have been found in temperature and H2O channels of SABER that resulted in re-analysisof Level 0/1 data performed by SABER team.
• The H2O non-LTE model has been validated for downward scans using the overlapping measurements performed by ACE-FTS and SABER.
• The H2O VMRs retrieved with the updated non-LTE model are in agreement with other measurements.
Future plans
• Obtain new T, P, and radiances with gain switching issues fixed.
• Re-do the non-LTE model update using the 2 minimum search approach. Use ACE-FTS data possibly supplemented by other H2O dataset (suggestions?).
• Implement updated non-LTE H2O model to SOPC
• Begin H2O VMR retrievals