1. The Atmospheric Chemistry Experiment (ACE): Latest Results Peter Bernath Department of Chemistry, University of York Heslington, York, UK and Department of Chemistry, Old Dominion University, Norfolk, VA (Aug. 2011)

2. The Shambles, Medieval York, UK Norfolk Harbor, Norfolk, Virginia

3. ACE Mission is Applied Spectroscopy Second edition now includes line strength formulas and their derivation for microwave (JPL), infrared (HITRAN) and electronic transitions plus light scattering.

4. ACE Goals To investigate the chemical and dynamical processes that control the distribution of ozone in the stratosphere and upper troposphere with a particular focus on the Arctic winter stratosphere. To accomplish this,  Temperature and pressure will be measured.  ACE will measure the concentrations of more than 30 molecules as a function of altitude.  Aerosols will be measured and quantified.

5. ACE Satellite Bernath et al., GRL, 32, L15S01 (2005) http://www.ace.uwaterloo.ca/

6. Solar Occultation Advantages: 1.Radiance of sun gives higher S/N than emission 2.Limb view gives longer path length ~500 km (lower detection limits) than nadir (but lower horizontal resolution) 3.“Self-calibrating” so excellent long-term accuracy and precision Disadvantages: 1.Modest global coverage 2.Samples only free troposphere (>5 km or so)

7. Timeline (“faster, cheaper”)  Jan.1998Proposal to Can. Space Agency (CSA)  Feb. 2001FTS and Imager CDR  Mar. 2001MAESTRO CDR  Jun. 2001Bus CDR  Sept. 2002S/C integration & test  Mar. 2003Instrument test (Toronto)  May 2003 Final integration (DFL)  Aug. 2003Launch  Sept.2003 Commissioning  Feb.2004Routine operations First ACE data Feb. 2004, mission currently approved to March 2012. Mission had a planned 2- year lifetime – eighth anniversary Aug. 2011. Curtis Rinsland

8. Instruments  Infrared Fourier Transform Spectrometer operating between 2 and 13 microns (750-4400 cm -1 ) 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  Startracker

9. Optical Layout (ABB-Bomem)

10. ACE-FTS (ABB-Bomem) Interferometer-sideInput optics-side

11. Integration to S/C Bus (DFL, Ottawa)

12. Pegasus XL Launch Vehicle (Aug. 12, 2003)

13. ACE Orbit- Global Coverage 650 km, 74° inclined circular orbit

14. Global Occultation Distribution

15. FTS – Decontamination Results After 6 months operation After decontamination Ryan Hughes 750-4400 cm -1 SNR>300 in 2 s scan

16. Occultation Sequence NB: retrieved tangent height

17. ACE-FTS Version 3 Species Tracers: H 2 O, O 3, N 2 O, NO, NO 2, HNO 3, N 2 O 5, H 2 O 2, HO 2 NO 2, N 2 Halogen-containing gases: HCl, HF, ClONO 2, CFC-11, CFC-12, CFC- 113, COF 2, COCl 2, COFCl, CF 4, SF 6, CH 3 Cl, CCl 4, HCFC-22, HCFC- 141b, HCFC-142b Carbon-containing gases: CO, CH 4, CH 3 OH, H 2 CO, HCOOH, C 2 H 2, C 2 H 4, C 2 H 6, OCS, HCN as well as pressure and temperature from CO 2 lines Isotopologues: H 2 18 O, H 2 17 O, HDO, O 13 CO, OC 18 O, OC 17 O, O 13 C 18 O, 18 OO 2, O 18 OO, O 17 OO, N 15 NO, 15 NNO, N 2 18 O, N 2 17 O, 13 CO, C 18 O, C 17 O, 13 CH 4, CH 3 D, OC 34 S, O 13 CS Research species: ClO, acetone, PAN, HFC-23, etc. Retrievals are entirely dependent on lab spectroscopy: HITRAN.

18. Climate Change The Independent 21 Dec. 2006

19. Greenhouse Gases (IPCC) 1.CO 2 2.CH 4 3.N 2 O 4.Halocarb. 5.Trop. O 3 6.Strat. H 2 O “Indirect Greenhouse Gases (GHGs)” 1.CO 2.NO X 3.VOCs All can be measured by solar occultation IR spectroscopy.

20. ACE-FTS CO 2 line near 61 km Note: results are plotted on the raw measurement grid (unapodized). ACE-FTS measures CO 2, main greenhouse gas, but… Temperature from relative CO 2 line intensities; pressure from CO 2 line absorption, assuming a constant CO 2 concentration.

21. CO 2 Profiles from ACE-FTS Normal ACE retrieval uses constant CO 2 VMR to get T, p and tangent heights. Use N 2 continuum instead and then retrieve CO 2 VMR in 5- 25 km altitude range. Foucher et al., ACP 9, 2873 (2009) Lafferty et al., Appl. Opt. (1996)

23. ACE-FTS results for the 40°N- 60°N latitude band Foucher et al., ACP 11, 2455 (2011) ACE 9-10 km (red) CARIBIC (blue)

24. CO 2 Profiles from ACE for the 50°N- 60°N latitude band May 2006 July 2006 ACE (red) Carbontracker (blue) Flexpart (purple)

25. ACE CO 2 trend 50°N-60°N latitude

26. Helpful to add observed CO 2 profile information to total column observations.

27. Atmospheric CCl 4 G From Geoff Toon; Note line mixing in CO 2 Q-branch CO 2 line mixingH 2 O non-Voigt line shapes

28. First Global CCl 4 Distribution N. Allen et al., ACP 9, 7449 (2009) CCl 4 produces Cl 2 CO peak in stratosphere

29. Atmospheric Phosgene, Cl 2 CO Toon et al., GRL 28, 2835 (2001) ν 5 (C-Cl antisymmetic stretching mode) at 849 cm -1 observed with MkIV balloon-borne FTS.

30. Global Distribution of Phosgene, Cl 2 CO D. Fu et al., GRL 34, L17815 (2007) Cl C O װ

31. Halogen Budget and Trends Species Global Warming Potential (20 year time horizon) Carbon Dioxide1 Methane72 Nitrous Oxide289 CFC - 116,730 CFC - 1211,000 CFC - 1136,540 Carbon Tetrachloride2,700 HCFC - 225,160 HCFC - 141b2,250 HCFC - 142b5,490 HFC - 134a3,830 Sulphur Hexafluoride16,300 Carbon Tetrafluoride (PFC - 14) 5,210 Retrievals v. 3.0: CFC-11, CFC-12, CFC-113, HCFC- 22, HCFC-141b, HCFC-142b, CCl 4, CH 3 Cl, CF 4, SF 6, (HFC-134a), F 2 CO, ClFCO, Cl 2 CO, HCl, HF, ClONO 2, (ClO) A. Brown and C. Boone

32. SF 6 HCFC-142b (CH 3 CClF 2 ) HCFC-22 (CHClF 2 ) CFC-12 (CCl 2 F 2 )

33. 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, OH ACE Solar Spectrum http://www.ace.uwaterloo.ca/ Used in Leicester for IASI CO retrievals

34. Confusion Limit OH v=2-1 P 1 (2.5) OH v=1-0 P 1 (6.5) Every bump is an atomic or molecular line: confusion limit!

35. IR NH Spectra Lab: Hollow cathode emission ACE Solar ATMOS Solar Improved vibration- rotation and pure rotation IR spectroscopy: OH, Bernath & Colin JMS 257, 20 (2009) NH, Ram & Bernath JMS 260, 115 (2010) CH, Colin & Bernath JMS 263, 120 (2010)

36. Air Quality and Biomass Burning

37. VOCs and Air Quality Volatile Organic Compounds (VOCs) lead to the production of tropospheric ozone, a pollutant & GHG.

38. Formaldehyde in the Troposphere  Directly emitted: biomass burning, incomplete combustion, industrial emissions, emissions from vegetation  Secondary product: oxidation of most anthropogenic and biogenic hydrocarbons (including methane and isoprene)  Important role in HOx and NOy radical cycling  Influence the oxidative capacity of the atmosphere  Effect on the tropospheric O 3 budget  Important test species in evaluating our mechanistic understanding of tropospheric oxidation reactions  Surface, aircraft, and satellite measurements  HCHO tropospheric columns (GOME, SCIAMACHY, OMI, GOME-2) used for inferring isoprene emissions

39. HCHO contribution to the spectrum 6 spectral windows selected in the range 2735 - 2830 cm -1 : 2739.85 ; 2765.65 ; 2778.4 ; 2781.2 ; 2812.25 ; 2826.67 Perrin et al., JQSRT 110, 700 (2009) Dufour et al., ACP 9, 3893 (2009)

40. Formaldehyde Seasonal Zonal Means

41. Atmospheric Dynamics: Asian Summer Monsoon Anticyclone At 13.5 km in altitude, HCN is high over Tibet because of rapid lofting of polluted air from India and China during summer; it is lower over the Pacific Ocean because of deposition and destruction in the ocean. Randel et al., Science 328, 611 (2010). (model)(Obs)

43. Fox News

44. Molecular Spectroscopy Facility at Rutherford Appleton Lab Bruker IFS 125 HR, with short path and long path coolable cells

45. Ethane, Propane and Acetone (3 micron region) Harrison et al., JQSRT 111, 357 (2010) Harrison & Bernath, JQSRT 111, 1282 (2010) Harrison et al., JQSRT, 112, 53 (SW region) and 457 (LW region)(2011)

46. Harrison et al., JQSRT (2011) Acetone Measurements ν 5 and ν 16 1365 cm -1 CH 3 deform. bands ~195 K ~197 K

47. ↑ acetone Methane Near Acetone Q-branch at 1365 cm -1 ACE spectrum near 15 km for occultation sr10063. Residuals for all of the measurements in the occultation between 8 and 25 km are shown on a common plot. The bottom panel plots the residuals when a combination of line mixing and speed dependence is used for the CH 4 lines.

48. Acetone Retrievals (Boone) Narrow microwindow 1364.7 - 1367.1 cm -1 covering the Q- branch. Line mixing and speed-dependent Voigt parameters derived from ACE spectra.

49. ACE Partners (Selected) Canada- K. Walker, J. Drummond, K. Strong, J. McConnell, W. Evans, T. McElroy, I. Folkins, R. Martin, J. Sloan, T. Shepherd, T. Llewellyn, etc. USA- NASA launched ACE: C. Rinsland, L. Thomason (NASA-Langley), C. Randall (U. Colorado), M. Santee, L. Froidevaux, G. Toon, 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), etc. France- C. Camy-Peyret, C. Clerbaux, C. Brogniez, G. Dufour, D. Hauglustaine (Paris) Japan- M. Suzuki (JAXA), Y. Kasai Sweden- G. Witt (Stockholm) Funding: CSA, NSERC, NERC,...

50. ESA-NASA ExoMars Trace Gas Orbiter JPL will send a “copy” of ACE-FTS (called MATMOS) to Mars in 2016 to look for organic signatures of life (e.g., methane).