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New Line List of Magnetic Dipole and Electric Quadrupole Transitions in the Band of Oxygen

This paper discusses the development of a new line list for magnetic dipole and electric quadrupole transitions in the oxygen band. It explores the use of remote sensing for accurate measurements of greenhouse gases and the calibration of oxygen mixing. The paper also addresses challenges and improvements for future updates.

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New Line List of Magnetic Dipole and Electric Quadrupole Transitions in the Band of Oxygen

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  1. - a1Dg — X 3Sg Towards New Line List of Magnetic Dipole and Electric Quadrupole Transitions in the Band of Oxygen Iouli E. Gordon Laurence S. Rothman Samir Kassi Alain Campargue Geoffrey C. Toon HITRAN Conference,Cambridge MA, USA June, 2010

  2. b 1Σ+ b 1Σ+ g - X 3Σg Lowest electronic states of O2 0.76 µm M1- Magnetic dipole E2- Electric quadrupole M1>> E2 E2 • Remote sensing in relation to high-accuracy measurements of atmospheric greenhouse gases such as CO2 and CH4 • Uniform mixing of oxygen provides calibration and removes systematic errors • ASCENDSmission • Nightglow in planetary atmospheres 1.27 µm a 1g M1, E2 M1, E2

  3. FTS in Park Falls

  4. Problems in HITRAN 2000-2008 • Intensities are derived in the pure case (b) coupling case, which leads to several percent error for transitions with low rotational quantum numbers. • An additional error in programming intensities. Intensities need to be multiplied by a factor of (line/ band origin)3. • Line positions are based on the precise MW constants of the excited state and unpublished term value of Brault for principal isotopologue, however for the 16O18O species outdated constants from Herzberg and Herzberg are used. • Two lines of the16O18O were missing.

  5. Orr-Ewing et al. line list and HITRAN update in November 2009 • Intensities for the 16O2 were recalculated by Prof. Orr-Ewing using correct formalism based on the intensity measurements by Newman et al (J Phys Chem A 2000;104:9467-80) • Additional corrections are described in Washenfelder et al. (Journal of Geophysical Research (Atmospheres) 2006;111:22305) and include introduction of empirical corrections of Yang et al (JQSRT 2005;90:309-21) air broadened half-widths and their temperature dependencies. Later update included line shifts from Robichaud et al measured in the A band divided by 2.

  6. - X 3Σg Lowest electronic states of O2 0.76 µm M1- Magnetic dipole b 1Σ+ g E2- Electric quadrupole M1>> E2 E2 1.27 µm a 1g M1, E2 M1, E2 F2 (J=N+S-1) F1 (J=N+S) F3 (J=N-S)

  7. Quadrupole transitions J=±2 J=±1 J=0 J e 12 Notation of branches: ΔN(N'')ΔJ(J'') 11 f 10 e 9 f e 8 7 f e 6 O(9)O(9) R(9)R(9) P(9)P(9) Q(9)Q(9) S(9)S(9) P(9)Q(8) Q(9)R(8) Q(9)P(10) N(9)O(8) S(9)R(10) O(9)P(8) R(9)Q(10) R(9)S(8) P(9)O(10) T(9)S(10) 9 f F2 N=9 F1 10 e 8 e F3

  8. threshold Laser OFF 100 -50 0 50 6nm/diode 30 DFB diodes Laser diode Lambdameter n=f(T,I) Optical isolator Coupler AO Modulator laser ON Photodiode CRDS measurements in Grenoble Large dynamic range of the measured intensities: absorption coefficients from 10-5to 10-10cm-1 are measured on a single spectrum Routine sensitivity: 10-10 cm-1,ie 1 % absorbance for 300 km path length

  9. CRDS measurements in Grenoble • 16 quadrupole transitions were measured

  10. Quadrupole line list calculation Details of the calculations are given in Gordon et al (JQSRT 111 (2010) 1174–1183)

  11. Inclusion of quadrupole J = ±2 transitions

  12. J=0,±1 and J=±2 J=0,±1 J=±2

  13. Complete set of CRDS measurements Measurements in 16O, 18O and 17O enriched mixtures!!! Leshchishina et al JQSRT (accepted)

  14. Hyperfine Structure

  15. Things to do in the next update • Use correct line strengths formulas derived for the mixed coupling case. Use new CRDS data as the input. Especially important for 16O18O. • Add electric quadrupole transitions. • Remove correlation between magnetic dipole and electric quadrupole transitions. • Recalculate line positions for all isotopologues using new CRDS data. Leshchishina et al JQSRT (accepted). • Add 16O17O (0-0) and 16O2 (1-1) transitions that have similar intensities to the quadrupole band. • Lineshape parameters, new measurements needed.

  16. Quadrupole transitions J=±2 J=±1 J=0 J e 12 Notation of branches: ΔN(N'')ΔJ(J'') 11 f 10 e 9 f e 8 7 f e 6 O(9)O(9) R(9)R(9) P(9)P(9) Q(9)Q(9) S(9)S(9) P(9)Q(8) Q(9)R(8) Q(9)P(10) N(9)O(8) S(9)R(10) O(9)P(8) R(9)Q(10) R(9)S(8) P(9)O(10) T(9)S(10) 9 f F2 N=9 F1 10 e 8 e F3

  17. Acknowledgements • J.-F. Blavier, R. Washenfelder, P. Wennberg • O. Leshchishina, L. Wang • A. Orr-Ewing • R. W. Field • S. Yu • NASA and ANR “IDEO”

  18. CRDS vs HITRAN (2009 update)

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