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Revision of Spectral Parameters for the B- and γ-Bands of Oxygen and their Validation using Atmospheric Spectra with the Sun as Source 66 th International.

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Presentation on theme: "Revision of Spectral Parameters for the B- and γ-Bands of Oxygen and their Validation using Atmospheric Spectra with the Sun as Source 66 th International."— Presentation transcript:

1 Revision of Spectral Parameters for the B- and γ-Bands of Oxygen and their Validation using Atmospheric Spectra with the Sun as Source 66 th International Symposium on Molecular Spectroscopy The Ohio State University June 2011 Geoffrey C. Toon Jet Propulsion Laboratory Laurence S. Rothman, Iouli E. Gordon Harvard-Smithsonian Center for Astrophysics

2 Importance of Molecular Oxygen Parameters in HITRAN  Uniformly mixed gas in terrestrial atmosphere  Bands in many spectral regions  Examples of remote-sensing applications - Satellite missions: OCO, GOSAT, SCIAMACHY, ACE... - Disentangling chlorophyll fluorescence from atmospheric scattering effects - Cloud-top height measurements - Wind measurements from space  Spectroscopic difficulties - Bands are inherently weak (magnetic dipole, electric quadrupole) - Line-shape issues - Collision Induced Absorption

3 a 1  g X 3 Σ g - b 1 Σ + g v = 1 B-band, 0.69 µm v = 0 A-band, 0.76 µm 1.27 µm γ-band, 0.63 µm v = 1 v = 0 v = 2 v = 3 Low-lying Vibronic States of Molecular Oxygen in HITRAN

4 447-m WLEF tower FTS near Tall Tower in Park Falls WI Total Column Carbon Observing Network (TCCON)

5 Comparison between HITRAN and Ground-based FTS observations for Oxygen B-band Experiment by G. Toon, at Wisconsin tower site Wavenumber (cm -1 ) RMS = 2.176% Recorded 22 Dec 2004

6 Comparison between New Analysis and Ground-based FTS observations for Oxygen B-band Wavenumber (cm -1 ) RMS = 0.868%

7 Kitt Peak National Solar Observatory (near Tucson Arizona)

8 Kitt Peak Fourier Transform Spectrometer

9 Residuals for γ-band using: a) HITRAN2008; b) HITRAN2008 supplemented by missing 2 lines at band head; and c) new line list

10 Parameter (cm -1 ) This workAlbritton et al a Cheah et al b Phillips et al c Naus et al d T1T (12) (17) (26) (12) B1B (72) (10) (22) (18) D1D (93) × (10) × (42) × (50) ×10 -6 T2T (27) (16) (32) (3) B2B (23) (11) (38) (2) D2D (36) ×10 -6 Number of lines used in this work per band MW: 85; Raman: 94; b 1 Σ g + (v=1)  a 1 Δ g (v=0): 29; a 1 Δ g  X 3 Σ g − : 199; b 1 Σ g + (v=1)  X 3 Σ g − (v=0): 72; b 1 Σ g + (v=2)  X 3 Σ g − (v=0): 49 Spectroscopic parameters of the v = 1 and 2 levels of the b 1 Σ g + state of 16 O 2 a. Albritton DL, Harrop WJ, Schmeltekopf AL, Zare RN, J Mol Spectrosc 1973;46: b. Cheah S-L, Lee Y-P, Ogilvie JF, JQSRT 2000;64: c. Phillips AJ, Peters F, Hamilton PA, J Mol Spectrosc 1997;184:162-6 d. Naus H, Navaian K, Ubachs W, Spectrochimica Acta Part A 1999;55:

11 Parameter (cm -1 ) This work Babcock and Herzberg Naus et alHITRAN T1T (257) (3) B1B (35) (3) D1D (92) × (8) × T2T (207) B2B (36)1.279 D2D2 5.37(123) × ×10 -6 Number of lines used in this work per band MW: 85; b 1 Σ g + (v=1)  X 3 Σ g − (v=0): 72; b 1 Σ g + (v=2)  X 3 Σ g − (v=0): 49 Parameter (cm -1 )This work Babcock and Herzberg Naus et al T1T (20) (2) B1B (15) (15) D1D (21) × (2) ×10 -6 Spectroscopic parameters of the v= 1 and 2 levels of the b 1 Σ g + state of 16 O 18 O Spectroscopic parameters of the v=1 level of the b 1 Σ g + state of 16 O 17 O

12 Intensity Corrections Applied to B- and γ -bands of Oxygen in HITRAN  Global correction: All intensities in both bands were multiplied by All intensities in both bands were multiplied by to remove the long standing programming error. to remove the long standing programming error. ( line / band ) 3  B-band: Intensities were multiplied by 1.02 to make them more consistent Intensities were multiplied by 1.02 to make them more consistent with CRDS measurements by Lisak et al with CRDS measurements by Lisak et al Phys Rev A (2010). 16 O 17 O intensities had to be further multiplied by 1.5  γ -band: HITRAN intensities, which were based on HITRAN intensities, which were based on Mélières et al JQSRT (1985), were found to be underestimated by 20%. Interestingly, the intensities in Miller et al JQSRT (1976) were exactly 20% higher and therefore became our choice.

13 B-band improvements for the 16 O 17 O isotopologue

14 Self-broadened half widths in the B-band

15 Pressure shifts in the B-band

16 Improvements of Parameters for O 2  A-, B-, and γ -Bands ( level) - Positions and intensities of transitions - Self- and air-broadened half widths - Pressure shifts - Isotopologues ( 16 O 18 O, 16 O 17 O) b 1 Σ + g  Singlet-Delta bands ( level) - Positions and intensities of transitions - Self- and air-broadened half widths - Pressure shifts - Quadrupole transitions a 1  g  Microwave lines ( ground state) - Positions - Intensities of high-rotational transitions - Self- and air-broadened half widths - Isotopologues ( 16 O 18 O, 16 O 17 O) X 3 Σ g -

17 Future Improvements of Parameters for O 2  Line-coupling  Line shape deviations from Voigt  More laboratory controlled observations - High sensitivity, higher rotational levels - High sensitivity, higher rotational levels  Theory: refine relative line strength formulae  Atmospheric δ -Band ( 3 ← 0 vibration at.59 μm)  Add hot band (2-1) b 1 Σ + g X 3 Σ g -

18 SAO HITRAN team members Kelly Chance Iouli Gordon Gang Li Cyril Richard Cameron Mackie Acknowledgments Joseph Hodges Daniel Lisak Linda Brown Caroline Nowlan Funding Support NASA Earth Observing System NASA Planetary Atmospheres Program Cooperative Research Development Foundation

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20 NASA’s Aura mission EOS Aura is the last of the three main NASA EOS missions Aura was launched from Vandenberg Air Force base in July 2004 carrying four instruments High Resolution Dynamics Limb Sounder (HIRDLS) – An infra-red radiometer for sounding the stratosphere, mesosphere and upper troposphere (heritage from LIMS, SAMS, ISAMS) Microwave Limb Sounder (MLS) A microwave radiometer for sounding the stratosphere, mesosphere and upper troposphere (heritage from UARS) Ozone Monitoring Instrument (OMI) Measures column O 3, N 2 O, SO 2 and other species from UV/Visible solar backscatter (heritage from TOMS) Tropospheric Emission Spectrometer (TES) An infrared limb and nadir viewing Fourier transform spectrometer for measuring tropospheric O 3, CO and other species


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