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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.

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Presentation on theme: "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."— Presentation transcript:

1 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 a 1  g — X 3  g -

2 Lowest electronic states of O 2 a 1  g X 3 Σ g - M1- Magnetic dipole E2- Electric quadrupole M1, E2 E2 Remote sensing in relation to high-accuracy measurements of atmospheric greenhouse gases such as CO 2 and CH 4 –Uniform mixing of oxygen provides calibration and removes systematic errors –ASCENDS mission Nightglow in planetary atmospheres M1>> E2 1.27 µm 0.76 µm b 1 Σ + g

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 Line positions are based on the precise MW constants of the excited state and unpublished term value of Brault for principal isotopologue, however for the 16 O 18 O species outdated constants from Herzberg and Herzberg are used. Two lines of the 16 O 18 O were missing.

5 Orr-Ewing et al. line list and HITRAN update in November 2009 Intensities for the 16 O 2 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 Lowest electronic states of O 2 b 1 Σ + a 1  g X 3 Σ g - M1- Magnetic dipole E2- Electric quadrupole M1, E2 E2 M1>> E2 F 1 (J=N+S) F 2 (J=N+S-1) F 3 (J=N-S) 1.27 µm 0.76 µm g

7 Quadrupole transitions 8 9 10 8 9 11 7 6 12 e f e f f e e e f e J=±2J=±2  J=±1  J=0 T(9)S(10) R(9)S(8) P(9)O(10) S(9)S(9) O(9)O(9) N(9)O(8)S(9)R(10) R(9)R(9)P(9)P(9) O(9)P(8)R(9)Q(10) Q(9)Q(9) P(9)Q(8) J N=9 F1F1 F2F2 F3F3 Q(9)R(8) Q(9)P(10) Notation of branches: ΔN(N'')ΔJ(J'')

8 CRDS measurements in Grenoble laser ON -50050 100 Laser diode Photodiode Lambdameter Optical isolatorCoupler AO Modulator Laser OFF threshold =f(T,I) 6nm/diode 30 DFB diodes Routine sensitivity: 10 -10 cm -1, ie 1 % absorbance for 300 km path length Large dynamic range of the measured intensities: absorption coefficients from 10 -5 to 10 -10 cm -1 are measured on a single spectrum

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=±2J=±2  J=0,±1  J=0,±1 and J=±2J=±2J=±2J=±2

13 Complete set of CRDS measurements Measurements in 16 O, 18 O and 17 O 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 16 O 18 O. 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 16 O 17 O (0-0) and 16 O 2 (1-1) transitions that have similar intensities to the quadrupole band. Lineshape parameters, new measurements needed.

16 Quadrupole transitions 8 9 10 8 9 11 7 6 12 e f e f f e e e f e J=±2J=±2  J=±1  J=0 T(9)S(10) R(9)S(8) P(9)O(10) S(9)S(9) O(9)O(9) N(9)O(8)S(9)R(10) R(9)R(9)P(9)P(9) O(9)P(8)R(9)Q(10) Q(9)Q(9) P(9)Q(8) J N=9 F1F1 F2F2 F3F3 Q(9)R(8) Q(9)P(10) Notation of branches: ΔN(N'')ΔJ(J'')

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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