ACE Linelist Needs for the Linelist Needs for the Atmospheric Chemistry Atmospheric Chemistry

ExperimentExperiment

Chris Boone and Peter BernathChris Boone and Peter Bernath

Univ. of Waterloo, Waterloo, Ontario, Univ. of Waterloo, Waterloo, Ontario, CanadaCanada

HITRAN 2006 ConferenceHITRAN 2006 Conference

June 27, 2006June 27, 2006

ACE

Atmospheric Chemistry Atmospheric Chemistry ExperimentExperiment

Satellite mission for remote sensing of Satellite mission for remote sensing of the Earth’s atmosphere, with a primary the Earth’s atmosphere, with a primary focus on Arctic ozonefocus on Arctic ozone

Developed by the Canadian Space Developed by the Canadian Space AgencyAgency

Launched August 2003, science Launched August 2003, science operations began February 2004operations began February 2004

Operating well, no major problems yet.Operating well, no major problems yet. Currently funded through April 2007.Currently funded through April 2007.

ACESolar OccultationSolar Occultation

ACE

InstrumentsInstruments

Infrared Fourier Transform Spectrometer Infrared Fourier Transform Spectrometer operating between 2 and 13 microns with a operating between 2 and 13 microns with a resolution of 0.02 cmresolution of 0.02 cm-1-1 ( ( 25 cm MPD) 25 cm MPD)

2-channel visible/near infrared Imagers, 2-channel visible/near infrared Imagers, operating at 0.525 and 1.02 micronsoperating at 0.525 and 1.02 microns

UV / Visible spectrometer (MAESTRO) 0.285 UV / Visible spectrometer (MAESTRO) 0.285 to 1.03 microns, resolution ~1-2 nmto 1.03 microns, resolution ~1-2 nm

SuntrackerSuntracker StartrackerStartracker

ACE

ACE-FTS (ABB-Bomem)ACE-FTS (ABB-Bomem)

Interferometer-side Input optics-side

ACEExcellent SNR PerformanceExcellent SNR Performance

Sig

nal t

o N

oise

Rat

io

IRD Requirement

Note: after detector decontamination

ACEHH22OO

ss2617, 10.6 km, HITRAN 2004

0

0.2

0.4

0.6

0.8

1

1214.6 1214.7 1214.8 1214.9 1215 1215.1 1215.2 1215.3

wavenumber (cm-1)

tran

smit

tan

ce

obs

calc

-0.04-0.02

00.020.040.06

1214.6 1214.8 1215 1215.2

wavenumber (cm-1)

ob

s-c

alc

ss2617, 10.6 km, HITRAN 2006

0

0.1

0.2

0.3

0.40.5

0.6

0.7

0.8

0.9

1214.6 1214.7 1214.8 1214.9 1215 1215.1 1215.2 1215.3

wavenumber (cm-1)

tran

smit

tan

ce

obs

calc

-0.04-0.02

00.020.040.06

1214.6 1214.7 1214.8 1214.9 1215 1215.1 1215.2 1215.3

wavenumber (cm-1)

ob

s-c

alc

sr2617, 10.6 km, DLR H2O

00.10.20.30.40.50.60.70.80.9

1214.6 1214.7 1214.8 1214.9 1215 1215.1 1215.2 1215.3

wavenumber (cm-1)

tran

smit

tan

ce

obs

calc

-0.04-0.02

00.020.040.06

1214.6 1214.7 1214.8 1214.9 1215 1215.1 1215.2 1215.3

wavenumber (cm-1)

ob

s-ca

lc

HITRAN 2004: 7.746e-24, 0.06954

HITRAN 2006: 7.746e-24, 0.0768

DLR: 7.75e-24, 0.0768

ACE

Occultation with less Occultation with less waterwater

sr10063 H2O retrieval, 12.5 km

0.4

0.5

0.6

0.7

0.8

0.9

1

1987.2 1987.25 1987.3 1987.35 1987.4 1987.45wavenumber (cm-1)

tra

ns

mit

tan

ce

obs

HITRAN 2004

-0.02-0.01

00.010.02

1987.2 1987.25 1987.3 1987.35 1987.4 1987.45

res

idu

als

sr10063 H2O retrieval, 12.5 km

0.4

0.5

0.6

0.7

0.8

0.9

1

1987.2 1987.25 1987.3 1987.35 1987.4 1987.45

wavenumber (cm-1)

tra

ns

mit

tan

ce

obs

HITRAN 2006

-0.02-0.01

00.010.02

1987.2 1987.25 1987.3 1987.35 1987.4 1987.45

res

idu

als

The H2O lineshape problems only occur when working with high water levels (but not high enough for self-broadening parameters to be significant). When one has pressure broadening with lower water levels, the recently determined H2O broadening parameters give improved residuals.

ACEHH22O lineshapeO lineshape

Major problems at low altitudes, Major problems at low altitudes, makes it difficult to perform some makes it difficult to perform some retrievals in the lower troposphere.retrievals in the lower troposphere.

Voigt lineshape inappropriate?Voigt lineshape inappropriate? Variations along the line of sight Variations along the line of sight

playing some role?playing some role? HITRAN 2006 HHITRAN 2006 H22O parameters seem O parameters seem

to improve fitting (to improve fitting (22 decreases by 4 - decreases by 4 - 10%)10%)

ACECFC-113CFC-113

-0.05

0

0.05

1116 1117 1118 1119 1120 1121 1122

wavenumber (cm-1)

ob

s-c

alc

window containing CFC-113, sr10063, 9.1 km

-0.20

0.20.40.60.8

1116 1117 1118 1119 1120 1121 1122

wavenumber (cm-1)

tran

smit

tan

ce

obscalc

Bad water residual

Even in the low water case, large residuals from water lines complicate retrievals that need to go deep into the troposphere

ACEVersion 2.2 OzoneVersion 2.2 Ozone

Validation results: ACE-FTS ozone ~5% low Validation results: ACE-FTS ozone ~5% low near the profile peak compared to other near the profile peak compared to other measurements.measurements.

Microwindows in two wavenumber regions:Microwindows in two wavenumber regions:

“Cleaner” region given greater weight and pulled the fit.

Large residuals in the other region (compared to SNR)

ACE

Version 2.2 O3 microwindows

020406080

100

1000 1200 1400 1600 1800 2000 2200

wavenumber (cm-1)

alti

tud

e (k

m)

"O3 update" microwindows

020406080

100

950 1000 1050 1100 1150

wavenumber (cm-1)

alti

tud

e (k

m)

ACEOO33

sr10063 retrieved O3

0

20

40

60

80

100

0 2 4 6 8 10

volume mixing ratio (ppm by volume)

alt

itu

de

(k

m)

version 2.2 O3

O3 update

~3-4% increase between 15 and 50 km, leading to better agreement with other measurements.

ACEOO33 parameters parameters

Likely a ~4% discrepancy between Likely a ~4% discrepancy between the ozone line strength parameters in the ozone line strength parameters in the two wavenumber regions.the two wavenumber regions.

Results from the lower wavenumber Results from the lower wavenumber region agree better with validation region agree better with validation data; suggests a problem with the data; suggests a problem with the higher wavenumbers.higher wavenumbers.

ACEHNOHNO33

HNO3 (15 occultations averaged)

5101520253035

0 2 4 6 8 10 12volume mixing ratio (ppb by volume)

alt

itu

de

(k

m)

1700 cm-1 band

900 cm-1 band

Improved consistency with the HITRAN 2004 linelist (compared to previous versions), but there remains a significant discrepancy between the two wavenumber regions.

ACENN22

N2, HITRAN 2004

25

27

29

31

33

35

0.5 0.6 0.7 0.8 0.9volume mixing ratio

alti

tud

e (k

m) S7

S8S9S10S11S12expectations

N2, new parameters

25

27

29

31

33

35

0.5 0.6 0.7 0.8 0.9volume mixing ratio

alti

tud

e (k

m)

S7

S8

S9

S10

S11

S12

expectations

N2, new parameters and scaled

25

27

29

31

33

35

0.5 0.6 0.7 0.8 0.9volume mixing ratio

alti

tud

e (k

m) S7

S8

S9

S10

S11

S12

expectations

Improved N2 parameters from Aaron Goldman (see his poster for more details).

ACECC22HH66

Q-branch

Unidentified spectral features in C2H6 fitting microwindow

ACECC22HH66

C2H6 Q-branches returned to the linelist, but of poorer quality than the feature near 2976.8 cm-1

ACECOClFCOClF

Lab spectrum from Kitt Peak, courtesy of Curtis Rinsland

ACECOClF in ACE spectraCOClF in ACE spectra

Region containing COClF, sr10063, 21.27 km

0.60.650.7

0.750.8

0.850.9

0.951

1.05

1864.9 1865 1865.1 1865.2 1865.3 1865.4 1865.5 1865.6 1865.7 1865.8 1865.9

wavenumber (cm-1)

tran

smit

tan

ce

obs

calc

-0.015-0.01

-0.0050

0.0050.01

1864.9 1865.1 1865.3 1865.5 1865.7 1865.9

wavenumber (cm-1)

ob

s-ca

lc

? ?

ACE

Sparse Cross-Section Sparse Cross-Section DataData

HNOHNO44: 1 cross-section file, difficult to : 1 cross-section file, difficult to perform a retrievalperform a retrieval

PAN: 2 files (2 different frequency PAN: 2 files (2 different frequency regions)regions)

HCFC-142b: 3 measurements (253, 270, HCFC-142b: 3 measurements (253, 270, and 287 K). Ideally, the data would go and 287 K). Ideally, the data would go lower in T for atmospheric worklower in T for atmospheric work

CHCH33CN: 3 measurements (276.1, 298.7, CN: 3 measurements (276.1, 298.7, and 324.1 K). Again, ideally lower T.and 324.1 K). Again, ideally lower T.

ACEConclusionsConclusions

Strong push into troposphere:Strong push into troposphere:– Improved waterImproved water– CFCs and HCFCsCFCs and HCFCs– Hydrocarbons (e.g., acetone, propane,…)Hydrocarbons (e.g., acetone, propane,…)

The listed errors on COThe listed errors on CO22 line intensities line intensities are 2-5%. The accuracy of everything are 2-5%. The accuracy of everything ties back to COties back to CO22 (through pressure and (through pressure and temperature). It would be nice to have temperature). It would be nice to have smaller errors.smaller errors.