ATMOSPHERIC CHEMISTRY EXPERIMENT (ACE) Some recent highlights Peter Bernath1,2, Chris Boone2, Hugh Pumphrey3 1Old Dominion University, Norfolk, VA 2University of Waterloo, Waterloo, ON 3University of Edinburgh, Scotland

HITRAN Special Issue (JQSRT) Submissions now closed; nearly 50 papers in total; important for next ACE-FTS version 4.0 retrievals The HITRAN2016 Molecular Spectroscopic Database, I. E. Gordon, L. S. Rothman, C. Hill, R. V. Kochanov, Y. Tan, P. F. Bernath, M. Birk, et al. Ames-2016 Line Lists for 13 Isotopologues of CO2: Updates, Consistency, and Remaining Issues X. Huang Validation of ozone intensities at 10 microns with THz spectrometry B. Drouin Measurement of air-broadening line shape parameters and temperature dependence parameters of H2O lines in the spectral ranges 1850 – 2280 cm-1 and 2390 – 4000 cm-1 J. Loos High resolution infrared spectra of the 16O16O17O and the 16O17O16O ozone isotopic species. The 5 and 10 micron spectral ranges revisited. E. Starikova Measurements and modeling of N2-broadening coefficients for the ν6 band of CH3F, comparison with CH3Cl and CH3Br molecules A. B. Ramchani Measurements and modeling of 16O12C17O spectroscopic parameters at 2 µm K. Sung Semi-empirical calculations of line-shape parameters and their temperature dependences for parallel bands of monodeuterated methane perturbed by nitrogen J. Buldyreva Accurate line intensities for water transitions in the infrared: comparison of theory and experiment J. Tennyson Recommended acetylene line list in the 20 − 240 cm–1 and 400 − 630 cm–1 regions: new measurements and global modeling D. Jacquemart Measurement of positions, intensities and self-broadening line shape parameters of H2O lines in the spectral ranges 1850 – 2280 cm-1 and 2390 – 4000 cm-1 J. Loos Room temperature linelists for CO2 asymmetric isotopologues with ab initio computed intensities ACE is a spectroscopy mission

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

ACE-FTS Version 3.5/3.6 Species Tracers: H2O, O3, N2O, NO, NO2, HNO3, N2O5, H2O2, HO2NO2, N2 Halogen-containing gases: HCl, HF, ClONO2, CFC-11, CFC-12, CFC-113, COF2, COCl2, COFCl, CF4, SF6, CH3Cl, CCl4, HCFC-22, HCFC-141b, HCFC-142b Carbon-containing gases: CO, CH4, CH3OH, H2CO, HCOOH, C2H2, C2H6, OCS, HCN, [CO2] as well as pressure and temperature from CO2 lines Isotopologues: H218O, H217O, HDO, O13CO, OC18O, OC17O, O13C18O, 18OO2, O18OO, O17OO, N15NO, 15NNO, N218O, N217O, 13CO, C18O, C17O, 13CH4, CH3D, OC34S, O13CS Research species: ClO, acetone, PAN, HFC-23, acetonitrile, HFC-134a, etc. ACE is now in its 14th year on orbit. This longevity makes trend analysis feasible (with care). The change in atmospheric composition is the primary driver of climate change.

Near-Real Time Processing, Version 3.6 ACE-FTS Version 3.5 data (UNIX Sun/Solaris): Feb. 2004 to Mar. 2013. ACE-FTS Version 3.6 (Linux): Nov. 2012 to present. Overlap period: Nov. 2012 to Mar. 2013, v. 3.6 mixed with v. 3.5 Version 4.0 includes many lost occultations. Near-real time processing by Waterloo: Level 2 data available with 2-day delay (remarkable for a small science mission) Daily Validation Check by Waterloo O3 N2O

Occultation Finder Tool

HCN and Fires Curtis Rinsland Enhanced HCN emitted from fires.

HCN 450-ppt Isosurface in July 2004 HCN budget from ACE data by Lupu et al., Atmos. Chem. Phys., 9, 4301 (2009) Emission 1.3 Tg N/yr Ocean uptake 1.2 Oxidation by OH 0.1 Atmospheric burden 0.5 Tg N Atmospheric lifetime 5 mon

Atmospheric Dynamics: Asian Summer Monsoon Anticyclone (Obs) (model) 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).

El Niño/Southern Oscillation (ENSO) “MLS measurements of stratospheric hydrogen cyanide during the 2015-16 El Niño event” by Hugh Pumphrey et al. (in preparation) 2015-2016 During an El Niño event, the Eastern Pacific sea surface temperature is warmer than normal. The atmospheric circulation changes; Australia and Indonesia tend to have droughts and increased fire activity. 1997-1998

HCN from Ground-based FTSs at Mauna Loa, Jungfraujoch and Kitt Peak P(8) line of ν1 band at 3287.25 cm-1; Rinsland et al., JGR 105, 24235 (2000)

ACE HCN Spectra R(5) line of ν1 band at 3328.77 cm-1 H2O HCN 33.6 km

Tropical HCN from MLS, MIPAS and ACE Time series of tropical HCN anomalies. Notice the striped effect particularly in the ACE data. Strong enhancement of HCN in 2016 is due to extensive fires in Indonesia. MIPAS MIPAS MIPAS ACE ACE ACE

Tropical HCN from MLS, MIPAS and ACE

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