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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
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SABER H2O RETRIEVAL: CURRENT STATUS AND FUTURE PLANS A.G. Feofilov1,2, A.A. Kutepov1,2,W.D. Pesnell1, R.A. Goldberg1 1 - NASA GSFC, Greenbelt, MD2 – Catholic University of America, Washington, DC SABER Team Meeting, June 15,16, 2009, Hampton, VA
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 transitions V-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 e
H2O radiance in 6.3µm band: LTE and NLTE Non-LTE LTE
Best case scenario Pressure, temperature,VMRs of other constituents H2O non-LTE model 6.6 m radiance Retrieved H2O VMR
Real life H2O non-LTE model Sensitivity study Set of parameters to be validated Comparisons with correlative H2O dataset Updated H2O non-LTE model 6.6 m radiance Pressure, temperature,VMRs of atmospheric gases Validation,correction Validation,correction Retrieved H2O VMR
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
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 calculationwith 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 radiancein 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.
Comparisons in numbers Microwave monitoring systemat ALOMAR (69.2°N) MLS, HALOE, and WVMS at Lauder (45°S) and Mauna Loa (19.5°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