OH A-X in Mesospheric Limb Spectra: OH A-X in Mesospheric Limb Spectra Databases OSIRIS – OH A-X ACE-FTS – H2O HALOE – H2O SORCE – Lyman α MSIS, ECMWF Presented at the LIMB Workshop Montreal, April 2006


OH A-X Initiatives: OH A-X Initiatives Derive OH Densities Diurnal and Seasonal Latitude and Longitude OH as H2O Proxy in Upper Mesosphere OSIRIS Data from November, 2001 to Present OH in PMC’s (?)


OSIRIS Limb Spectra: OSIRIS Limb Spectra OH 0-0 Band at 308 nm OH 1-1 Band at 314 nm Background Subtracted Band Shape Comparisons OK


OH Limb Radiance to OH Density : OH Limb Radiance to OH Density OH Forward Model Iterative Approximation Collisional Deactivation, Self Extinction MAHRSI ‘g’ Factors Noise Estimates


Error Sources: Error Sources Electron Noise in Rayleigh Plus OH Electron Noise in Rayleigh Reference Error in Baseline Fitting at Anchor Points Anchors on Either Side of Target Band 3 or More Pixels in Each Anchor Region Errors Combined as Root Sum Square Does NOT Include Systematic Errors (<15%) Note : Correct for NO Bands Avoid PMC’s Avoid N2 Second Positive Auroral Signature at 317 nm


Derived OH Profiles: Derived OH Profiles April 20-21 2005 70º North Latitude HALOE H2O Input Photochemical Model 16:45 SLT 08:05 SLT Average of 15 Profiles


Model OH Diurnal Variation at 80 km: Model OH Diurnal Variation at 80 km HOX Removed at Night. Recovers Slowly in Morning Major Source is Solar Lyman α on H2O Results Below for Early June at 60º North Range of H2O Mixing Ratios


Extended OSIRIS Limb Spectra : Extended OSIRIS Limb Spectra 4 June 2005 59º N 183º E 68º SZA 17:40 LT (Late Afternoon) OH 1-0 at 282 nm


OSIRIS Limb Minus Rayleigh Background: OSIRIS Limb Minus Rayleigh Background 4 June 2005 59º N 183º E 68º SZA 17:40 LT (Late Afternoon)


OSIRIS OH Density Profiles – Late Spring: OSIRIS OH Density Profiles – Late Spring 4 June 2005 59º N 183º E 68º SZA 17:40 LT (Late Afternoon) High H2O Mixing Ratio at 80 km


Select Bright OH Scans: Select Bright OH Scans To Improve Band Ratio Measurements Detected Bright Early Morning OH Scan Profile Not Typical Source ?? Typical Truncated


(ACE-FTS H2O + Model) vs (OSIRIS OH) : (ACE-FTS H2O + Model) vs (OSIRIS OH) ACE-FTS H2O ACE-FTS H2O + Model vs OSIRIS OH


OSIRIS OH vs Model OH: OSIRIS OH vs Model OH ‘Validate’ OSIRIS OH Use ACE-FTS H2O with Model Latitude within 2º Local Time within 30 minutes


OSIRIS OH and PMC’s : OSIRIS OH and PMC’s Compare OH X Density Maps with PMC Maps OH as Proxy for Water Vapour via Lyman α May, June, July, August 2005 Both for 83 km (OH X Horizontal Slice) Correlation ? Anti-correlation ? Also July 2002, 2003


PMC Index Definition: PMC Index Definition Wavelength for PMC Index is 312 nm, Clear of OH Checked OK for 290 nm and 300 nm PMC Index is Loge [Backscatter Ratio (BSR)] Index > 0.3 is Definitive PMC Signature Maximum Index Clipped at 3.0 to Enhance Faint Events Note : Maximum Observed PMC BSR ~ 30 BSR Reference 76 km and 90 km, Underestimates


OH Spring Summer 2005 PM 83 km : OH Spring Summer 2005 PM 83 km 24 Mar 2005 06 Aug 2005 27 May 2005 02 Jul 2005 29 Apr 2005 12 Sep 2005


PMC’s North 2005 PM 83 km : PMC’s North 2005 PM 83 km 04 June 2005 02 July 2005 27 May 2005 15 Aug. 2005 28 July 2005 03 Sept. 2005


OH and PMC’s 2005 PM: OH and PMC’s 2005 PM 23 June 2005 PM OH PMC 02 July 2005 PM


OH and PMC’s 23 June 2005 PM: OH and PMC’s 23 June 2005 PM OH and PMC’s Anti-correlated ?? Sanity Check on OH !! Spectra OK ?? Considerable Background ‘Noise’ Increase Extinction < 3% (at 300 nm, 100/cc, 50 nm Radius, Mie, BSR 30) Faint PMC 77N 130E Bright PMC 76N 037E


OH and PMC’s 02 July 2005 PM : OH and PMC’s 02 July 2005 PM Faint PMC 77N 092E Bright PMC 79N 015E


OH and PMC’s 2005 AM : OH and PMC’s 2005 AM 23 June 2005 AM OH PMC 02 July 2005 AM


OH and PMC’s 2002 2003 PM : OH and PMC’s 2002 2003 PM 02 July 2002 PM OH PMC 01 July 2003 PM


OH and PMC’s 2002 2003 AM : OH and PMC’s 2002 2003 AM 02 July 2002 AM OH PMC 01 July 2003 AM


Infer Total H2O from OH + PMC: Infer Total H2O from OH + PMC OH  (H2O)0.5 from Photochemical Model (Figure Below) HALOE Maximum H2O ~ 4 ppmv from PMC Ice (Hervig et al.) HALOE Latitude Range 65ºN to 70ºN OSIRIS PMC Index 70ºN to 82ºN > 2 x (Index 65ºN to 70ºN) Assume Maximum H2O ~ 8 ppmv from PMC Ice H2O Vapour (OH) H2O Ice (PMC) H2O Total H2O OH


Total H2O 23 June 2005 : Total H2O 23 June 2005 H2O Vapour (OH) H2O Ice (PMC) 83 km Afternoon OH  (H2O)0.5 Ice Max. 8 ppmv


Total H2O 02 July 2005 : Total H2O 02 July 2005 H2O Vapour (OH) H2O Ice (PMC) 83 km Afternoon OH  (H2O)0.5 Ice Max. 8 ppmv


Total H2O 02 July 2002 : Total H2O 02 July 2002 H2O Vapour (OH) H2O Ice (PMC) 83 km Afternoon OH  (H2O)0.5 Ice Max. 8 ppmv


Total H2O 01 July 2003 : Total H2O 01 July 2003 H2O Vapour (OH) H2O Ice (PMC) 83 km Afternoon OH  (H2O)0.5 Ice Max. 8 ppmv


PMC Tentative Conclusions: PMC Tentative Conclusions OSIRIS Bright OH and Strong PMC Signals Anti-correlated Considerable Spatial Variability in Total H2O (Sum of Two Sources) Tests vs PMC Models Essential – Require Colocated T(K) The End