Atmospheric Chemistry Experiment (ACE):

Recent ResultsPeter Bernath (and ACE team)

Department of Chemistry, University of York

Heslington, York, UK

and

Department of Chemistry, University of Waterloo, Waterloo, ON, Canada

ACE Satellite

See http://www.ace.uwaterloo.ca

Solar Occultation

Advantages: Radiance of sun gives higher S/N than emissionLimb view gives longer path length ~500 km (lower detection limits) than nadir“Self-calibrating” so excellent long-term accuracy and precisionDisadvantages: Modest global coverageSamples only free troposphere

Timeline Jan. 1998 Proposal to CSA Feb. 2001 FTS and Imager CDR Mar. 2001 MAESTRO CDR Jun. 2001 Bus CDR Sept. 2002 S/C integration & test Mar. 2003 Instrument test (Toronto) May 2003 Final integration (DFL) Aug. 2003 Launch Sept. 2003 Commissioning Feb. 2004 Routine operations Mar. 2004 Arctic campaign Feb. 2005 Arctic campaign Feb. 2006 Arctic campaign Feb. 2007 Arctic campaign Feb. 2008 Arctic campaign

First ACE data Feb. 2004, mission currently approved to March 2010. Mission had a 2-year lifetime – fifth anniversary Aug. 2008.

Instruments

Infrared Fourier Transform Spectrometer operating between 2 and 13 microns with a resolution of 0.02 cm-1

2-channel visible/near infrared Imagers, operating at 0.525 and 1.02 microns (cf., SAGE II)

Suntracker keeps the instruments pointed at the sun’s radiometric center.

UV / Visible spectrometer (MAESTRO) 0.4 to 1.03 microns, resolution ~1-2 nm

StartrackerBernath et al. GRL, 32, L15S01 (2005)

SCISAT-1 Spacecraft (Bristol)

Optical Layout (ABB-Bomem)

Secondaymirror (6)

Field stop (5)

IR Filter(7)

Suntrackermirror (1)

Aperturestop (4)

PV MCTDetector

(18)

Glare stop(16)

Coolerwindow (17)

Outputcondenser

(14)

INTcorner-cubemirror (10)

End mirror(13)

INTcorner-cubemirror (11)

(12)

(9)

(12): Reflective coating(9): B/S coating

Beamsplit ter/compensatorassembly (8)

Primary mirror (3)

Fold mirror(22)

Lenses(23)

0.525 mimager (28)

1.02 mimager (26)

Dichroic(24)

Solarinput

Compensator

VIS/NIR-Quad CellDichroic

Quad Cell(21)

Lenses(20)

LaserMetrologyDetection

1.02 mfilter (25)

0.525 mfilter (27)

Beam splitter

Foldmirror(15) Laser Metrology Insertion

MAESTROInterface (2)

PV InSbDetector

Lens

Lens Glare stop

Dichroic

1.55 mfilter (19)

MAESTRO

Dual concave grating spectrograph, 1-2 nm resolution

MAESTRO PI:T. McElroy, MSC

Global Occultation Distribution

FTS – Decontamination Results

After 6 months operationAfter decontamination

Ryan Hughes

Occultation sequence

ACE-FTS Species Measured

Baseline species (version 2.2):

H2O, O3, N2O, CO, CH4, NO, NO2, HNO3, HF, HCl, N2O5, ClONO2, CCl2F2, CCl3F, as well as pressure and temperature from CO2 lines

Other routine species:

COF2, CHF2Cl, CF4, CH3Cl, C2H6, SF6, OCS, HCN

Research species:

CCl4, HOCl, H2O2, HO2NO2, CCl2FCClF2, CH3CClF2, ClO, C2H2, C2H6, COFCl, COCl2, CH3OH, HCOOH, H2CO, N2 and additional isotopologues

CO2 line near 61 km

Typical ACE-FTS fitting results

Note: results are plotted on the raw measurement grid

Boone et al. Appl. Opt. 44, 7218 (2005)

Temperature Retrievals-CO2

90 km

15 km

Schwartz et al. JGR, 113, D15S11 (2008)

Stratospheric Chlorine Budget

Mean ClTOT (ppbv) slope (ppbv/km) Northern high latitudes 3.74 ± 0.12 0.010 ± 0.001 Northern midlatitudes 3.65 ± 0.09 0.007 ± 0.001 Tropics 3.62 ± 0.11 0.009 ± 0.001 Southern midlatitudes 3.65 ± 0.09 0.007 ± 0.001 Southern high latitudes 3.71 ± 0.16 0.014 ± 0.001

Northern Midlatitudes

Southern Midlatitudes

Current HALOE value 3.3 ppb

Nassar et al.

WMO Ozone Report 2006

JGR, 111, D22312 (2006)

CFC-11, CFC-12 , HCFC-22, CCl4, CH3Cl, CF4, CFC-113, HCFC-142b, HFC134a, F2CO, ClFCO,

Cl2CO

Asian Monsoon Anticyclone

Park et al., ACP, 8, 757 (2008)

Global Distribution of Phosgene, Cl2CO

Latitude (in Degrees)

Alt

itu

de

(in

Km

)

2004-2005-2006 COCl2 Volume Mixing Ratio (in pptv)

-80 -60 -40 -20 0 20 40 60 800

5

10

15

20

25

30

35

40

0

10

20

30

40

50

60

Fu et al. GRL, 34, L17815 (2007) (Toon et al.’s calculated linelist for ν5 near 850 cm-1)

-10 0 10 20 30 400

5

10

15

20

25

30

Volume Mixing Ratio (in pptv)

Alt

itu

de

(in

km

)

85oS-60oS

60oS-30oS

30oS-30oN

30oN-60oN

60oN-90oNWilson et al. 1988Kindler et al. 1995

50oN-80oN

0o-90oN

0o-85oS

Cl ClC

Oװ

Distribution of COClF

•Carbonyl chlorofluoride is a product of chlorofluorocarbon (CFC-11 mainly) decomposition

•Previously studied by aircraft (5 - 12 km)

•First global picture obtained from ACE-FTS

•Spectroscopy based on Brown’s ATMOS linelist created from Kitt Peak spectra, with rough intensities.

D. Fu et al., to be submitted

Effect of Lightning (HNO3)

Lightning produces NO, which is oxidized to HNO3.

Need to have 6 Tg N/yr from lightning to match ACE observations of tropospheric HNO3 (Martin et al. JGR, 112, D09309 (2007))

ACE solar spectrum (F. Hase): 224782 spectra added, improvement over ATMOS, no telluric lines, but 0.02 cm-1 vs 0.01 cm-1 resolution (resolution largely determined by width of solar lines) and 750-4400 cm-1 vs 600-4800 cm-1.

CO, Δv=1

OH

CO Δv=2

CH, NH, OHACE Solar Spectrum

ATMOS Spacelab-3, 1985

ATMOS ATLAS-3, 1994

ACE, 2008

New atomic and molecular assignments (ACE linelist) by L. Wallace (NOAO); improved spectroscopic data for CH, NH and OH.

For OH, Reg Colin (ULB) finds v=4 can be improved.

Air Quality and Biomass Burning

Biomass Burning in Brazil

MODIS Fire Counts26 Sept. 200427 Sept. 200428 Sept. 2004

5

6

7

8

9

10

11

12

13

14

15

16

17

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

ss6139 - v2.1 CO*0.01 O

3*0.01

HCN C

2H

6

vmr (ppbv)

altit

ude

(km

)

CH3OH contribution to the spectrum

Dufour et al. ACP, 6, 3463 (2006); data from Xu et al. 2004

Global Methanol

Dufour et al. ACP, 7, 6119, 2007

LDMz-INCA model

(D. Hauglustaine)

ACE is an upper tropospheric “air quality” mission measuring global CH4, CH3OH, HCN, C2H2, C2H6, H2O2, HCOOH, H2CO, plus likely PAN and acetone.

Young Biomass Burning Plume

Coheur et al. ACP, 7, 547, 2007

PAN, Peroxyacetyl nitrate, etc.

Coheur et al. (Brussels), PAN from a biomass plume near East Africa

HCHO spectroscopy: new linelist

Use of HCHO line intensities calculated by A. Perrin

2831,6 2831,7 2831,8 2831,9 2832,0 2832,1 2832,2

0,0

0,2

0,4

0,6

0,8

1,0

Perrin, Jacquemart, Kwabia-Tchana & Lacome

1 22

1 22-21

1 21

1 21

3 18-20

3 175 8

0 8-8

1 7

Obs-Calc New Calc

Calc with HITRAN*1.28

Calc New calc

Obs

Tra

nsm

itta

nce

Wavenumber in cm-1

Missing lines

Error with multiplets

Dufour et al.

HCHO contribution to the spectrum

0,0

0,2

0,4

0,6

0,8

-0,05

0,00

0,05

2778,0 2778,2 2778,4 2778,6 2778,8

-0,05

0,00

0,05

Observed spectrum

without HCHO HCHO contribution

HCHO contributionwith HCHO

0,0

0,2

0,4

0,6

0,8

-0,10-0,050,000,050,10

2780,8 2780,9 2781,0 2781,1 2781,2 2781,3 2781,4 2781,5 2781,6-0,10-0,050,000,050,10

Observed spectrum

HCHO contributionwithout HCHO

HCHO contributionwith HCHO

6 spectral windows selected in 6 spectral windows selected in the range 2735 - 2830 cmthe range 2735 - 2830 cm-1-1 ::

2739.85 ; 2765.65 ; 2778.4 ; 2739.85 ; 2765.65 ; 2778.4 ; 2781.2 ; 2812.25 ; 2826.672781.2 ; 2812.25 ; 2826.67

0,2

0,4

0,6

0,8

-0,05

0,00

0,05

2826,2 2826,4 2826,6 2826,8 2827,0-0,05

0,00

0,05

Observed spectrum

HCHO contributionwithout HCHO

HCHO contributionwith HCHO

3 years of HCHO measurements with ACE-FTS

Preliminary comparisons with CTMs

MAM04 JJA04 SON04 DJF05 MAM05 JJA05 SON05 DJF06 MAM06 JJA06 SON06

10

20

30

40

50

60

70

80

90

100

110

120

MAM04 JJA04 SON04 DJF05 MAM05 JJA05 SON05 DJF06 MAM06 JJA06 SON06

102030405060708090

100110120130140150

MAM04 JJA04 SON04 DJF05 MAM05 JJA05 SON05 DJF06 MAM06 JJA06 SON06

30

40

50

60

70

80

90

100

HC

HO

vm

r (p

ptv)

LMDz-INCA ACE-FTS GEOS-CHEM

North Americar = 0.96r = 0.93

HC

HO

vm

r (p

ptv)

Europe-Russiar = 0.98r = 0.93

HC

HO

vm

r (p

ptv)

South Tropicsr = 0.0r = 0.38

8.5 kmComparison with 2 state-of-the-art models (LMDz-INCA and GEOS-Chem) that use different emissions inventories.North Hemisphere: seasonality of UT HCHO well reproduced intensity of the maximum not always reproduced

South Hemisphere: LMDz-INCA systematically smaller

South Tropics: small impact of biomass burning larger variability in the models

ACE Partners (Selected)

Canada- K. Walker, J. Drummond, K. Strong, J. McConnell, W. Evans, T. McElroy, I. Folkins, R. Martin, J. Sloan, T. Shepherd, etc.

USA- NASA launched ACE: C. Rinsland, L. Thomason (NASA-Langley), C. Randall (U. Colorado), B. Bojkov (NASA-Goddard), M. Santee, L. Froidevaux, G. Manney (JPL), etc.

Belgium- supplied CMOS imager chips: R. Colin, P.-F. Coheur, M. Carleer (ULB), D. Fussen, M. DeMaziere (IASB), M. Mahieu, R. Zander (Liege), etc.

UK- J. Remedios (Leicester), P. Palmer (Edinburgh), M. Chipperfield (Leeds)

France- C. Camy-Peyret, C. Clerbaux, C. Brogniez, G. Dufour, D. Hauglustaine (Paris)

Japan- M. Suzuki, Y. Kasai (JAXA) Sweden- G. Witt (Stockholm)

Sunset over Kitt Peak, AZ