Cl
O = C <F
Of statospheric & tropospheric interest !
The ν1, ν2, and ν3 bands of carbonyl
chlorofluoride (COFCl) at 5.3 µm, 9.1 µm, and
13.1 µm:.
JQSRT 112, p1266 (2011)
Agnès Perrin, LISA, Créteil France
Spectroscopy
Jean Demaison PhLAM, Villeneuve d’Ascq
Ab Initio
Hans Bürger, University of Wuttertal
FTS spectra for COFCl
Geoffrey Toon, JPL, Pasadena, USA
Atmosphere
O=C
Cl
<F
(see the talk of Jean-Pierre Pommereau on
yesterday !!)
• Carbonyl chlorofluoride (COFCl) is an important reservoir of
chlorine and fluorine in the Earth’s atmosphere
• Major source of atmospheric COFCl is CFC-11 (CCl3F).
• Although CFC-12 (CCl2F2) is the most abundant fluorinecontaining source gas, it most likely breaks down to form
COF2 instead of COFCl.
• This is because CFC's oxidation in the stratosphere occurs
by breaking of the C-Cl bonds before any C-F bond is
cleaved
O=C
Cl
<F
No COFCl linelist available in HITRAN or
GEISA
In the 1990’s….
The (medium resolution)
COFCl linelist for ATMOS
(Linda Brown)
COFCl: a (medium resolution) line list was
generated specifically for the ATMOS
experiment (1987 & 1996)
ν3
ν1
ν2
COFCl
?
?
strongest
•
•
???
COF35Cl
v.s.
COF37Cl
No rotational
assignments
(no E’’)
Brown L R, Framer C B, Rinsland C P, Toth R A. Molecular line parameters for the atmospheric
trace molecule spectroscopy experiment (ATMOS) . ApplOpt 1987;26:5154–82.
Brown L R, Atmospheric trace molecule spectroscopy (ATMOS) linelist. Appl Opt
1996;35:2828–48.
In the 2000’s….
We undertaken 2 high
resolution spectroscopic
studies of COFCl
2001 & 2003
High resolution FTS spectra recorded in Wuppertal
for COF35Cl & for natural COFCl
(Hans Bürger , Univ. Wuppertal) uneasy
synthesis !!!
[1] Perrin, Flaud, H.Bürger, Pawelke, Sander & Willner: First
high resolution analysis of the six fundamental bands ν1,
ν2, ν3, ν4, ν5 and ν6 of COF35Cl . J Mol Spectrosc
2001;209:122.
[2] Demaison, Perrin, & H.Bürger: “Ab Initio Anharmonic Force
Field and Equilibrium Structure of COFCl,
COF37Cl: ν3 band .
J Mol Spectrosc 2003;221:47-56.
In the 2007’s….
COFCl is retrieved by ACEFTS…
In 2007
Satellite-based remote sensing measurements
performed by the Atmospheric Chemistry
Experiment Fourier transform spectrometer
(ACE-FTS) have been used to achieve
retrievals of COFCl during 2004-2007 period
using …
the 1990’s ATMOS medium resolution
linelist
¤ Nassar, Bernath , Boone, Clerbaux, Coheur, Dufour, Froidevaux. Mahieu ,
McConnell, McLeod, Murtagh, Rinsland, Semeniuk, Skelton, Walker, and
Zander. J Geophys Res 2006;111:D22312.
¤ Rinsland CP, Nassar R, Boone CD, Bernath PF, Chiou L, Weisenstein DK,
Mahieu E, and Zander R. Spectroscopic detection of COClF in the tropical and
mid-latitude lower stratosphere. JQSRT 2007;105:467–475
In the 2011
Geoffrey Toon (JPL,
Pasadena) asked us a new
and more accurate and
complete linelist COFCl
O=C
Cl
<F
O=C
Cl
<F
??
??
??
O=C
Cl
<F
1873.8
1094.8
??
408
666
Intensities ???
2011
2001
• High resolution FTS
spectra recorded in
Wuppertal (H.Bürger) for
COF35Cl & natural
COFCl
• The ν1, ν2 & ν3 bands of
COF35Cl (2001)
• Analysis of the ν2 & ν3 band
of COF37Cl
• Estimation of the ν1 COF37Cl
• The A/B intensity pattern for
the ν1, ν2 and ν3 bands of
COFCl
• Ab initio studies
(J.Demaison)
• Prediction of the « absolute
intensities
• For COF37Cl : Prediction of the
band centers and of the A, B
and C rotational constants
The ν3 band of COF37Cl & COF35Cl
The ν2 band of CO35FCl & COF37Cl
The ν1 bands of COF35Cl & COF37Cl
r
a
h
An
ni
o
m
e
r
c
e
c
an
n
so
s
In 2011: Atmospheric applications
Geoffrey Toon, JPL lab
Evaluation using MkIV balloon spectra of the
ATMOS (1990’s) and new (2011) linelists
ν3
Integrated line intensity :
ATMOS 1996,
ν1
?
?
?
COFCl
ATMOS 1996
ν2
ν3
Integrated line intensity
: Perrin & Demaison 2011
COF35Cl
COF37Cl
Perrin & Demaison
2010-09-30
ν1
Evaluation using MkIV
balloon spectra
with the new list
ν2
ν3
ν1
With
the ATMOS
list
Evaluation
using MkIV
balloon spectra
with the ATMOS list
ν2
Absent in the ATMOS list
ν3
ν1
Evaluation using MkIV
balloon spectra
relative to the COFCl
retrievals using the
new list in the ν2
region
ν3
ν2
ν1
The COFCl linelists; (Perrin & Demaison) and ATMOS
have been evaluated using JPL MkIV balloon
spectra.
⇒ Band-to-band consistency of retrieved COFCl
763 cm-1
1095 cm-1
1875 cm-1
Linelist
(ν3)
(ν2)
0.81±
±0.02 N/A
ATMOS
(Brown, ‘96)
New linelist
2011
(ν1)
1.25±
±0.01
25% of
error !!!
0.96±
±0.02 1.00±
±0.01 1.04±
±0.01
Impact of new COFCl spectroscopy for
HCOOH
Retrieval of atmospheric
HCOOH performed using the
ν6 band centered at 1105 cm1.
with and without the new
COFCl linelist (ν
ν2 band of
COFCl).
In the absence of the ν2 COFCl
linelist , the retrieved
HCOOH vmr is overestimated by 20% in the 1525km altitude range.
Note also that the blue error bars are
slightly smaller than the red due to the
better spectral fits.
MIPAS spectrum at 13 µm (J.Orphal, IMK, private
Portion of thecommunication)
MIPAS spectrum at 21.7 km
J.Orphal, Michael Hoepfner Gaby Stiller , IMK Germany
Cl-35
Cl-37
No COFCl
With COFCl
Conclusion
• A new COFCl linelist for the ν1, ν2 and ν3 bands of COF35Cl
and COF37Cl was generated using high resolution spectra
recorded in Wuppertal
• Absolute intensities were achieved from ab initio
calculations
• This list has been evaluated using MkIV balloon spectra
(JPL)
• Retrieved profiles of COFCl are improved by nearly a factor
2 in terms of their uncertainties compared with the ATMOS
• It improves
linelist also the HCOOH retrievals
• COFCl is easily observable in the MIPAS spectra: in
the 13 µm region, both the 35Cl and 37Cl signature
are observable
ATMOS
Retrieved COFCl profiles
New
linelist
errors
The ν3 band of COF37Cl & COF35Cl
Portion of the MIPAS spectrum at 21.7 km
J.Orphal, Michael Hoepfner Gaby Stiller , IMK Germany
Cl-35
Cl-37
No COFCl
With COFCl
ν1 Band Comparison
ν2 Band Comparison
Absent from ATMOS linelist
ν3 Band Comparison
References
Perrin, A., J.-M. Flaud, H. Burger, G. Pawelke, S. Sander,z and H. Willnerz, First HighResolution Analysis of the Six Fundamental Bands ν1, ν2,ν3, ν4, ν5, and ν6 of COF35Cl
in the 340- to 2000-cm-1 Region, Journal of Molecular Spectroscopy 209, 122–132 (2001)
Demaison, A. J., A. Perrin, and H. Burger, Ab initio anharmonic force field and equilibrium
structure of carbonyl chlorofluoride, Journal of Molecular Spectroscopy 221 (2003) 47–56
Rinsland, C. P., Ray Nassar, Chris D. Boone, Peter Bernath, Linda Chiou, Debra K.
Weisenstein, Emmanuel Mahieu, Rodolphe Zander, Spectroscopic detection of COClF in
the tropical and mid-latitude lower stratosphere, JQSRT, 105 (2007) 467–475
Fu, D., Chris D.Boone, Peter F.Bernath, Debra K.Weisenstein, Curtis P.Rinsland, Gloria
L.Manney, Kaley A.Walker, First global observations of atmospheric COClF from the
Atmospheric Chemistry Experiment mission, JQSRT, 110 (2009) 974–985
Anderson, W. D., M. C. L. Gerry, and C. J. Marsden, "The Microwave Spectrum, Harmonic
Force Field, and Structure of Carbonyl Chlorofluoride, OCClF," J. Mol. Spectr. 114, 70
(1985)
Brown LR, Farmer CB, Rinsland CP, Toth RA. Molecular line parameters for the atmospheric
trace molecule spectroscopy experiment. Appl Opt 1987;26:5154–82.
Brown LR, Gunson MR, Toth RA, Irion FW, Rinsland CP, Goldman A. 1995 atmospheric trace
molecule spectroscopy (ATMOS) linelist. Appl Opt 1996;35:2828–48