ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-10621-2010 Peroxy radical partitioning during the AMMA radical intercomparison exercise Andrés-Hernández M. D. 1 Stone D. 2 3 Brookes D. M. 4 Commane R. 2 9 Reeves C. E. 5 Huntrieser H. 6 Heard D. E. 2 7 Monks P. S. 4 Burrows J. P. 1 Schlager H. 6 Kartal D. 1 Evans M. J. 3 Floquet C. F. A. 2 Ingham T. 2 7 Methven J. 8 Parker A. E. 4 Institute of Environmental Physics, University of Bremen, Bremen, Germany School of Chemistry, University of Leeds, Leeds, UK School of Earth and Environment, University of Leeds, Leeds, UK Department of Chemistry, University of Leicester, Leicester, UK School of Environmental Sciences, University of East Anglia, Norwich, UK Institute of Atmospheric Physics, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany National Centre for Atmospheric Science, University of Leeds, Leeds, UK Department of Meteorology, University of Reading, Reading, UK now at: School of Engineering and Applied Science, Harvard University, Cambridge, USA 11 11 2010 10 21 10621 10638 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/10621/2010/acp-10-10621-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/10621/2010/acp-10-10621-2010.pdf

Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis) campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO<sub>2</sub> by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE) and total peroxy radicals (RO<sub>2</sub>* = HO<sub>2</sub>+ΣRO<sub>2</sub>, R = organic chain) by two similar instruments based on the peroxy radical chemical amplification (PeRCA) technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO<sub>2</sub>, NO<sub>y</sub>, O<sub>3</sub> and a wider range of VOCs were collected simultaneously. <br></br> Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO<sub>2</sub>* data available agree quite reasonably within the instrumental errors. The [RO<sub>2</sub>*]/[HO<sub>2</sub>] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

 References Andrés-Hernández, M. D., Burkert, J., Reichert, L., Stöbener, D., Meyer-Arnek, J., Burrows, J. P., Dickerson, R. R., and Doddridge, B.: Marine boundary layer peroxy radical chemistry during the AEROSOLS99 campaign: measurements and analysis, J. Geophys. Res., 106(D18), 20833–20846, 2001. Andrés-Hernández, M. D., Kartal, D., Reichert, L., Burrows, J. P., Meyer Arnek, J., Lichtenstern, M., Stock, P., and Schlager, H.: Peroxy radical observations over West Africa during AMMA 2006: photochemical activity in the outflow of convective systems, Atmos. Chem. Phys., 9, 3681–3695, doi:10.5194/acp-9-3681-2009, 2009. Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J., Troe, J., and IUPAC Subcommittee: Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species, Atmos. Chem. Phys., 6, 3625–4055, doi:10.5194/acp-6-3625-2006, 2006. Bechara, J., Borbon, A., Jambert, C., Colomb, A., and Perros, P. E.: Evidence of the impact of deep convection on reactive volatile organic compounds in the upper tropical troposphere during the AMMA experiment in West Africa, Atmos. Chem. Phys. Discuss., 9, 20309–20346, doi:10.5194/acpd-9-20309-2009, 2009. Brookes, D.: Characterisation of a PeRCA instrument and measurements of peroxy radicals during the West African Monsoon~2006, Ph.D thesis, University of Leicester, UK, https://lra.le.ac.uk/handle/2381/8328, 2009. Brough, N., Reeves, C. E., Penkett, S. A., Stewart, D. J., Dewey, K., Kent, J., Barjat, H., Monks, P. S., Ziereis, H., Stock, P., Huntrieser, H., and Schlager, H.: Intercomparison of aircraft instruments on board the C-130 and Falcon 20 over southern Germany during EXPORT 2000, Atmos. Chem. Phys., 3, 2127–2138, doi:10.5194/acp-3-2127-2003, 2003. Brune, W. H., Faloona, I. C., Tan, D., Weinheimer, A. J., et al.: Airborne in-situ OH and HO<sub>2</sub> observations in the cloud-free troposphere and lower stratosphere during SUCCESS, Geophys. Res. Lett., 25(10), 1701–1704, 1998. Burkert, J., Andrés-Hernández, M. D., Stöbener, D., Burrows, J. P., Weissenmayer, M., and Kraus, A.: Peroxy radical and related trace gas measurements in the boundary layer above the Atlantic Ocean, J. Geophys. Res., 106(6), 5457–5477, doi:10.1029/2000JD900613, 2001a. Burkert, J., Behmann, T., Andrés Hernández, M. D., Weißenmayer, M., Perner, D., and Burrows, J. P.: Measurements of peroxy radicals in a forested area in Portugal, Chemosphere, 3(3), 3327–3338, 2001b. Burkert, J. Andrés Hernández, M. D., Reichert, L., Stöbener, D., Meyer-Arnek, J., Burrows, J. P., Mühle, J., Zahn, A., Carsey, T., Dickerson, R. R., and Doddridge, B.: Trace gas and radical behaviour in the marine boundary layer during INDOEX~1999, J. Geophys. Res., 108(D8), 8000, doi:10.1029/2002JD002790, 2003. Cantrell, C. A., Shetter, R. E., and Calvert, J. G.: Dual-Inlet chemical amplifier for atmospheric peroxy radical measurements, Anal. Chem., 68, 4194–4199, 1996. Cantrell, C. A., Edwards, G. D., Stephens, S., Mauldin, L., et al.: Peroxy radical behaviour during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign as measured aboard the NASA~P-3B aircraft, J. Geophys. Res., 108(D20), 8797, doi:10.1029/2003JD003674, 2003a. Cantrell, C. A., Edwards, G. D., Stephens, S., Mauldin, L., Kosciuch, E., Zondlo, M., and Eisele, F.: Peroxy radical observations using chemical ionization mass spectrometry during TOPSE, J. Geophys. Res., 108(D6), 8371, doi:10.1029/2002JD002715, 2003b. Cantrell, C. A., Mauldin, L., Zondlo, M., Eisele, F., et al.: Steady free radical budgets and ozone photochemistry during TOPSE, J. Geophys. Res., 108(D4), 8361, doi:10.1029/2002JD002198, 2003c. Clemitshaw, K. C., Carpenter, L. J., Penkett S. A., and Jenkin, M. E.: A calibrated peroxy radical chemical amplifier for ground-based tropospheric measurements, J. Geophys. Res., 102(D21), 25–405, 1997. ommane, R., Floquet, C. F. A., Ingham, T., Stone, D., Evans, M. J., and Heard, D. E.: Observations of OH and HO<sub>2</sub> radicals over West Africa, Atmos. Chem. Phys., 10, 8783–8801, doi:10.5194/acp-10-8783-2010, 2010. Eisele, F. L., Mauldin, L., Cantrell, C., Zondlo, M., Apel, E., et al.: Summary of measurement intercomparisons during TRACE-P, J. Geophys. Res., 108(D20), 8791, doi:10.1029/ 2002JD003167, 2003. Emmerson, K. M. and Evans, M. J.: Comparison of tropospheric gas-phase chemistry schemes for use within global models, Atmos. Chem. Phys., 9, 1831–1845, doi:10.5194/acp-9-1831-2009, 2009. Gerbig, C., Schmitgen, S., Kley, D., Volz-Thomas, A., Dewey, K., and Haaks, D.: An improved fast-response vacuum-UV resonance fluorescence CO instrument, J. Geophys. Res., 104(D1), 1699–1704, 1999. Green, T. J., Brough, N., Reeves, C. E., Edwards, G. D., Monks, P. S., and Penkett, S. A.: Airborne measurements of peroxy radicals using the PeRCA technique, J. Environ. Monitor., 5, 75–83, 2003. Green, T. J., Reeves, C. E., Fleming, Z. L., Brough, N., Rickard, R. A., Bandy, B. J., Monks, P. S., and Penkett, S. A.: An improved dual channel PeRCA instrument for atmospheric measurements of peroxy radicals, J. Environ. Monitor., 8, 530–536, doi:10.1039/b514630e, 2006. Hanke, M., Uecker, J., Reiner, T., and Arnold, F.: Atmospheric peroxy radicals: ROXMAS, a new mass-spectrometric methodology for speciated measurements of HO<sub>2</sub> and $§igma$RO<sub>2</sub> and first results, Int. J. Mass Spectrom., 213(2–3), 91–99, 2002. Hastie, D. R., Weißenmayer, M., Burrows, J. P., and Harris, G. W.: Calibrated chemical amplifier for atmospheric RO<sub>x</sub> measurements, Anal. Chem., 63, 2048–2057, 1991. Hopkins, J. R., Lewis, A. C., and Read, K. A.: A two-column method for long-term monitoring of non-methane hydrocarbons (NMHCs) and oxygenated volatile organic compounds (o-VOCs), J. Environ. Monitor., 5(1), 8–13, 2003. Jaeglé, L., Jacob, D. J., Brune, W. H., and Wennberg, P. O.: Chemistry of HO<sub>x</sub> radicals in the upper troposphere, Atmos. Environ., 35, 469–489, 2001. Kartal, D.: Characterization and optimization optimisation of a dual channel PeRCA for the investigation of the chemistry of peroxy radicals in the upper troposphere, PhD thesis, University of Bremen, Germany, 2009. %Kartal, D., Andrés-Hernández, M. D., Reichert, L., Schlager, H., and %Burrows, J. P.: Technical Note: Characterisation of a DUALER instrument for %the airborne measurement of peroxy radicals during AMMA~2006, Atmos. Chem. %Phys., 10, 3047–3062, 2010. Kartal, D., Andrés-Hernández, M. D., Reichert, L., Schlager, H., and Burrows, J. P.: Technical Note: Characterisation of a DUALER instrument for the airborne measurement of peroxy radicals during AMMA 2006, Atmos. Chem. Phys., 10, 3047–3062, doi:10.5194/acp-10-3047-2010, 2010. Madronich, S. and Calvert, J. G.: Permutation reactions of organic peroxy radicals in the troposphere, J. Geophys. Res., 95, 5697–5715, doi:10.1029/JD095iD05p05697, 1990. %Martinez, M., Harder, H., Kubistin, D., Rudolf, M., Bozem, H., Eerdekens, G., %Fischer, H., Gurk, C., Klüpfel, T., Königstedt, R., Parchatka, U., %Schiller, C. L., Stickler, A., Williams, J., and Lelieveld, J.: Hydroxyl %radicals in the tropical troposphere over the Suriname rainforest: airborne %measurements, Atmos. Chem. Phys. Discuss., 8, 15491–15536, 2008. Martinez, M., Harder, H., Kubistin, D., Rudolf, M., Bozem, H., Eerdekens, G., Fischer, H., Klüpfel, T., Gurk, C., Königstedt, R., Parchatka, U., Schiller, C. L., Stickler, A., Williams, J., and Lelieveld, J.: Hydroxyl radicals in the tropical troposphere over the Suriname rainforest: airborne measurements, Atmos. Chem. Phys., 10, 3759–3773, doi:10.5194/acp-10-3759-2010, 2010. Mihele, C. M. and Hastie, D. R.: The sensitivity of the radical amplifier to ambient water vapour, Geophys. Res. Lett., 25, 1911–1913, 1998. Mihele, C. M., Mozurkewich, M., and Hastie, D. R.: Radical loss in a chain reaction of CO and NO in the presence of water: Implications for the radical amplifier and atmospheric chemistry, Int. J. Chem. Kinet., 31, 145–152, 1999. Monks, P. S.: Gas-phase radical chemistry in the troposphere, Chem. Soc. Rev., 34(5), 376–395, 2005. Murphy, J. G., Oram, D. E., and Reeves, C. E.: Measurements of volatile organic compounds over West Africa, Atmos. Chem. Phys. Discuss., 10, 3861–3892, 2010. Olson, J. R., Crawford, J. H., Chen, G., Fried, A., et al.: Testing fast photochemical theory during TRACE-P based on measurements of OH, HO<sub>2</sub> and CH<sub>2</sub>O, J. Geophys. Res., 109, D15S10, doi:101029/2003JD004278, 2004. Olson, J. R., Crawford, J. H., Chen, G., Brune, W. H., et al.: A reevaluation of airborne HO<sub>x</sub> observations from NASA field campaigns, J. Geophys. Res., 111, D10301, doi:101029/2005JD006617, 2006. Reeves, C. E., Formenti, P., Afif, C., Ancellet, G., Attié, J.-L., Bechara, J., Borbon, A., Cairo, F., Coe, H., Crumeyrolle, S., Fierli, F., Flamant, C., Gomes, L., Hamburger, T., Jambert, C., Law, K. S., Mari, C., Jones, R. L., Matsuki, A., Mead, M. I., Methven, J., Mills, G. P., Minikin, A., Murphy, J. G., Nielsen, J. K., Oram, D. E., Parker, D. J., Richter, A., Schlager, H., Schwarzenboeck, A., and Thouret, V.: Chemical and aerosol characterisation of the troposphere over West Africa during the monsoon period as part of AMMA, Atmos. Chem. Phys., 10, 7575–7601, doi:10.5194/acp-10-7575-2010, 2010. Reichert, L., Andrés Hernández, M. D., Stöbener, D., Burkert, J., and Burrows, J. P.: Investigation of the effect of water complexes in the determination of peroxy radical ambient concentrations: implications for the atmosphere, J. Geophys. Res., 108(D1), 4017–4032, 2003. Salisbury, G., Monks, P. S., Bauguitte, S., Bandy, B. J., and Penkett, S. A.: A Seasonal Comparison of the Ozone Photochemistry in Clean and Polluted Air Masses at Mace Head, Ireland, J. Atmos. Chem., 41, 163–187, 2002. Sander, S. P., Finlayson-Pitts, B. J., Friedl, R. R., Golden, D. M., Huie, R. E., Keller-Rudek, H., Kolb, C. E., Kurylo, M. J., Molina, M. J., Moortgat, G. K., Orkin, V. L., Ravishankara, A. R. and Wine, P. H., JPL Publication, 06–2, 2006. Sandu, A. and Sander, R.: Technical note: Simulating chemical systems in Fortran90 and Matlab with the Kinetic PreProcessor KPP-2.1, Atmos. Chem. Phys., 6, 187–195, doi:10.5194/acp-6-187-2006, 2006. Saunders, S. M., Jenkin, M. E., Derwent, R. G., and Pilling, M. J.: Protocol for the development of the Master Chemical Mechanism, MCM v3 (Part A): tropospheric degradation of non-aromatic volatile organic compounds, Atmos. Chem. Phys., 3, 161–180, doi:10.5194/acp-3-161-2003, 2003. Schlager, H., Konopka, P. Schulte, P., Schumann, U., Ziereis, H., Arnold, F., Klemm, M., Hagen, D., Whitefield, P., and Ovarlez, J.: In situ observations of air traffic emission signatures in the North Atlantic flight corridor, J. Geophys. Res., 102, 10739–10750, 1997. Schulte, P., Schlager, H., Schumann, U., Baughcum, S. L., and Deidwig, F.: NO$_\rm x$ emission indices of subsonic long-range jet aircraft at cruise altitude: In situ measurements and predictions, J. Geophys. Res., 102, 21431–21442, 1997. %Stewart, D. J., Taylor, C. M., Reeves, C. E., and McQuaid, J. B.: Biogenic %nitrogen oxide emissions from soils: impact on NO<sub>x</sub> and ozone over %west Africa during AMMA (African Monsoon Multidisciplinary Analysis): observational %study, Atmos. Chem. Phys., 8, 2285–2297, 2008. Stewart, D. J., Taylor, C. M., Reeves, C. E., and McQuaid, J. B.: Biogenic nitrogen oxide emissions from soils: impact on NOx and ozone over west Africa during AMMA (African Monsoon Multidisciplinary Analysis): observational study, Atmos. Chem. Phys., 8, 2285–2297, doi:10.5194/acp-8-2285-2008, 2008. %Stone, D., Evans, M. J., Commane, R., Ingham, T., Floquet, C. F. A., %McQuaid, J. B., Brookes, D. M., Monks, P. S., Purvis, R., Hamilton, J. %Hopkins, J., Lee, J., Lewis, A. C., Stewart, D., Murphy, J., Mills, G., %Oram, D., Reeves, C. E., and % Heard, D. E.: HO<sub>x</sub> observations over West Africa during AMMA: impact %of isoprene and NO$_x$, Atmos. Chem. Phys. Discuss., 10, 17029–17072, %2010. Stone, D., Evans, M. J., Commane, R., Ingham, T., Floquet, C. F. A., McQuaid, J. B., Brookes, D. M., Monks, P. S., Purvis, R., Hamilton, J. F., Hopkins, J., Lee, J., Lewis, A. C., Stewart, D., Murphy, J. G., Mills, G., Oram, D., Reeves, C. E., and Heard, D. E.: HO<sub>x</sub> observations over West Africa during AMMA: impact of isoprene and NO$_x$, Atmos. Chem. Phys., 10, 9415–9429, doi:10.5194/acp-10-9415-2010, 2010. Tyndall, G. S., Cox, R. A., Granier, C., Lesclaux, R., Moortgat, G. K., Pilling, M. J., Ravishankara, A. R., and Wallington, T. J.: Atmospheric chemistry of small organic peroxy radicals, J. Geophys. Res., 106, 12157–12182, 2001. Volz-Thomas, A., Lerner, A., Pfitz, H. W., Schultz, M., McKenna, D. S., Schmitt, R., Madronich, S., and Röth, E. P.: Airborne measurements of the photolysis frequency of NO<sub>2</sub>, J. Geophys. Res., 101(D13), 18613–18627, 1996. Zenker, T., Fischer, H., Nikitas, C., Parchatka, U., Harris, G. W., Mihelcic, D., Muesgen, P., Paetz, H. W., Schultz, M., Volz-Thomas, A., Schmitt, R., Behmann, T., Weissenmayer, M., and Burrows, J. P.: Intercomparison of NO, NO<sub>2</sub>, NO<sub>y</sub>, O<sub>3</sub> and RO<sub>x</sub> measurements during the OCTA campaign~1993 at Izaña, J. Geophys. Res., 103(D11), 13615–13634, 1998. Ziereis, H., Schlager, H., Schulte, P., van Velthoven, P., and Slemr, F.: Distributions of NO, NO<sub>x</sub>, and NO<sub>y</sub> in the upper troposphere and lower stratosphere between 28~and 61° N during POLINAT~2, J. Geophys. Res., 105, 3653–3664, 2000.