ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-12-6309-2012 Transport of short-lived species into the Tropical Tropopause Layer Ashfold M. J. 1 Harris N. R. P. 1 Atlas E. L. 2 Manning A. J. 3 Pyle J. A. 1 4 Department of Chemistry, University of Cambridge, Cambridge, UK Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA Met Office, Exeter, UK National Centre for Atmospheric Science, UK 19 07 2012 12 14 6309 6322 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/12/6309/2012/acp-12-6309-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/6309/2012/acp-12-6309-2012.pdf

We use NAME, a trajectory model, to investigate the routes and timescales over which air parcels reach the tropical tropopause layer (TTL). Our aim is to assist the planning of aircraft campaigns focussed on improving knowledge of such transport. We focus on Southeast Asia and the Western Pacific which appears to be a particularly important source of air that enters the TTL. We first study the TTL above Borneo in November 2008, under neutral El Niño/Southern Oscillation (ENSO) conditions. Air parcels (trajectories) arriving in the lower TTL (below ~15 km) are most likely to have travelled from the boundary layer (BL; <1 km) above the West Pacific. Few air parcels found above ~16 km travelled from the BL in the previous 15 days. We then perform similar calculations for moderate El Niño (2006) and La Niña (2007) conditions and find year-to-year variability consistent with the phase of ENSO. Under El Niño conditions fewer air parcels travel from the BL to the TTL above Borneo. During the La Niña year, more air parcels travel from the BL to the mid and upper TTL (above ~15 km) than in the ENSO-neutral year, and again they do so from the BL above the West Pacific. We also find intra-month variability in all years, with day-to-day differences of up to an order of magnitude in the fraction of an idealised short-lived tracer travelling from the BL to the TTL above Borneo. These calculations were performed as a prelude to the SHIVA field campaign, which took place in Borneo during November 2011. So finally, to validate our approach, we consider measurements made in two previous campaigns. The features of vertical profiles of short-lived species observed in the TTL during CR-AVE and TC4 are in broad agreement with calculated vertical profiles of idealised short-lived tracers. It will require large numbers of observations to fully describe the statistical distribution of short-lived species in the TTL. This modelling approach should prove valuable in planning flights for the long-duration aircraft now capable of making such measurements.

 References Aschmann, J., Sinnhuber, B.-M., Atlas, E. L., and Schauffler, S. M.: Modeling the transport of very short-lived substances into the tropical upper troposphere and lower stratosphere, Atmos. Chem. Phys., 9, 9237–9247, http://dx.doi.org/10.5194/acp-9-9237-2009doi:10.5194/acp-9-9237-2009, 2009. Butler, J H., King, D B., Lobert, J M., Montzka, S A., Yvon-Lewis, S A., Hall, B D., Warwick, N J., Mondeel, D J., Aydin, M., and Elkins, J W.: Oceanic distributions and emissions of short-lived halocarbons, Global Biogeochem. Cy., 21, GB1023, http://dx.doi.org/10.1029/2006GB002732doi:10.1029/2006GB002732, 2007. Carpenter, L. J., Wevill, D. J., O'Doherty, S., Spain, G., and Simmonds, P. G.: Atmospheric bromoform at Mace Head, Ireland: seasonality and evidence for a peatland source, Atmos. Chem. Phys., 5, 2927–2934, http://dx.doi.org/10.5194/acp-5-2927-2005doi:10.5194/acp-5-2927-2005, 2005. Davies, T., Cullen, M. J P., Malcolm, A J., Mawson, M H., Staniforth, A., White, A A., and Wood, N.: A new dynamical core for the Met Office's global and regional modelling of the atmosphere, Q. J. Roy. Meteorol. Soc., 131, 1759–1782, 2005. Dorf, M., Butler, J H., Butz, A., Camy-Peyret, C., Chipperfield, M P., Kritten, L., Montzka, S A., Simmes, B., Weidner, F., and Pfeilsticker, K.: Long-term observations of stratospheric bromine reveal slow down in growth, Geophys. Res. Lett., 33, L24803, http://dx.doi.org/10.1029/2006GL027714doi:10.1029/2006GL027714, 2006. FAO Fisheries and Aquaculture Department: The State of World Fisheries and Aquaculture 2010, Tech. rep., Food and Agriculture Organization of the United Nations, Rome, 2010. Flocke, F., Herman, R L., Salawitch, R J., Atlas, E., Webster, C R., Schauffler, S M., Lueb, R A., May, R D., Moyer, E J., Rosenlof, K H., Scott, D C., Blake, D R., and Bui, T P.: An examination of chemistry and transport processes in the tropical lower stratosphere using observations of long-lived and short-lived compounds obtained during STRAT and POLARIS, J. Geophys. Res., 104, 26625–26642, http://dx.doi.org/10.1029/1999JD900504doi:10.1029/1999JD900504, 1999. Fueglistaler, S., Wernli, H., and Peter, T.: Tropical troposphere-to-stratosphere transport inferred from trajectory calculations, J. Geophys. Res.-Atmos., 109, D03108, http://dx.doi.org/10.1029/2003JD004069doi:10.1029/2003JD004069, 2004. Fueglistaler, S., Dessler, A E., Dunkerton, T J., Folkins, I., Fu, Q., and Mote, P W.: Tropical Tropopause Layer, Rev. Geophys., 47, RG1004, http://dx.doi.org/10.1029/2008RG000267doi:10.1029/2008RG000267, 2009. Gettelman, A. and Forster, P. D F.: A Climatology of the Tropical Tropopause Layer, Journal of the Meteorological Society of Japan, 80, 911–924, 2002. Gettelman, A., Lauritzen, P H., Park, M., and Kay, J E.: Processes regulating short-lived species in the tropical tropopause layer, J. Geophys. Res.-Atmos., 114, D13303, http://dx.doi.org/10.1029/2009JD011785doi:10.1029/2009JD011785, 2009. Gostlow, B., Robinson, A. D., Harris, N. R. P., O'Brien, L. M., Oram, D. E., Mills, G. P., Newton, H. M., Yong, S. E., and A Pyle, J.: μDirac: an autonomous instrument for halocarbon measurements, Atmos. Meas. Tech., 3, 507–521, http://dx.doi.org/10.5194/amt-3-507-2010doi:10.5194/amt-3-507-2010, 2010. Heyes, W. J., Vaughan, G., Allen, G., Volz-Thomas, A., Pätz, H.-W., and Busen, R.: Composition of the TTL over Darwin: local mixing or long-range transport?, Atmos. Chem. Phys., 9, 7725–7736, http://dx.doi.org/10.5194/acp-9-7725-2009doi:10.5194/acp-9-7725-2009, 2009. Hosking, J. S., Russo, M. R., Braesicke, P., and Pyle, J. A.: Modelling deep convection and its impacts on the tropical tropopause layer, Atmos. Chem. Phys., 10, 11175–11188, http://dx.doi.org/10.5194/acp-10-11175-2010doi:10.5194/acp-10-11175-2010, 2010. Hossaini, R., Chipperfield, M. P., Monge-Sanz, B. M., Richards, N. A. D., Atlas, E., and Blake, D. R.: Bromoform and dibromomethane in the tropics: a 3-D model study of chemistry and transport, Atmos. Chem. Phys., 10, 719–735, http://dx.doi.org/10.5194/acp-10-719-2010doi:10.5194/acp-10-719-2010, 2010. Hoyle, C. R., Marécal, V., Russo, M. R., Allen, G., Arteta, J., Chemel, C., Chipperfield, M. P., D'Amato, F., Dessens, O., Feng, W., Hamilton, J. F., Harris, N. R. P., Hosking, J. S., Lewis, A. C., Morgenstern, O., Peter, T., Pyle, J. A., Reddmann, T., Richards, N. A. D., Telford, P. J., Tian, W., Viciani, S., Volz-Thomas, A., Wild, O., Yang, X., and Zeng, G.: Representation of tropical deep convection in atmospheric models – Part 2: Tracer transport, Atmos. Chem. Phys., 11, 8103–8131, http://dx.doi.org/10.5194/acp-11-8103-2011doi:10.5194/acp-11-8103-2011, 2011. Jones, A., Thomson, D., Hort, M., and Devenish, B.: The U.K. Met Office's Next-Generation Atmospheric Dispersion Model, NAME III, in: Air Pollution Modeling and Its Application XVII, edited by: Borrego, C. and Norman, A.-L., 580–589, Springer US, http://dx.doi.org/10.1007/978-0-387-68854-1_62doi:10.1007/978-0-387-68854-1_62, 2007. Krüger, K., Tegtmeier, S., and Rex, M.: Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter, Atmos. Chem. Phys., 8, 813–823, http://dx.doi.org/10.5194/acp-8-813-2008doi:10.5194/acp-8-813-2008, 2008. Krüger, K., Tegtmeier, S., and Rex, M.: Variability of residence time in the Tropical Tropopause Layer during Northern Hemisphere winter, Atmos. Chem. Phys., 9, 6717–6725, http://dx.doi.org/10.5194/acp-9-6717-2009doi:10.5194/acp-9-6717-2009, 2009. Laube, J. C., Engel, A., Bönisch, H., Möbius, T., Worton, D. R., Sturges, W. T., Grunow, K., and Schmidt, U.: Contribution of very short-lived organic substances to stratospheric chlorine and bromine in the tropics – a case study, Atmos. Chem. Phys., 8, 7325–7334, http://dx.doi.org/10.5194/acp-8-7325-2008doi:10.5194/acp-8-7325-2008, 2008. Lawrence, M G. and Rasch, P J.: Tracer Transport in Deep Convective Updrafts: Plume Ensemble versus Bulk Formulations, J. Atmos. Sci., 62, 2880–2894, http://dx.doi.org/10.1175/JAS3505.1doi:10.1175/JAS3505.1, 2005. Levine, J G., Braesicke, P., Harris, N. R P., Savage, N H., and Pyle, J A.: Pathways and timescales for troposphere-to-stratosphere transport via the tropical tropopause layer and their relevance for very short lived substances, J. Geophys. Res.-Atmos., 112, D04308, http://dx.doi.org/10.1029/2005JD006940doi:10.1029/2005JD006940, 2007. Levine, J. G., Braesicke, P., Harris, N. R. P., and Pyle, J. A.: Seasonal and inter-annual variations in troposphere-to-stratosphere transport from the tropical tropopause layer, Atmos. Chem. Phys., 8, 3689–3703, http://dx.doi.org/10.5194/acp-8-3689-2008doi:10.5194/acp-8-3689-2008, 2008. Liang, Q., Stolarski, R. S., Kawa, S. R., Nielsen, J. E., Douglass, A. R., Rodriguez, J. M., Blake, D. R., Atlas, E. L., and Ott, L. E.: Finding the missing stratospheric Bry: a global modeling study of CHBr<sub>3</sub> and CH<sub>2</sub>Br<sub>2</sub>, Atmos. Chem. Phys., 10, 2269–2286, http://dx.doi.org/10.5194/acp-10-2269-2010doi:10.5194/acp-10-2269-2010, 2010. Mata, T M., Martins, A A., and Caetano, N S.: Microalgae for biodiesel production and other applications: A review, Renewable and Sustainable Energy Reviews, 14, 217–232, http://dx.doi.org/10.1016/j.rser.2009.07.020doi:10.1016/j.rser.2009.07.020, 2010. Montzka, S A. and Reimann, S.: Ozone-Depleting Substances (ODSs) and Related Chemicals, vol. Scientific Assessment of Ozone Depletion: 2010, Global Ozone Research and Monitoring Project – Report No. 52, chap 1, World Meteorological Organization (WMO), Geneva, 2011. Morrison, N L. and Webster, H N.: An Assessment of Turbulence Profiles in Rural and Urban Environments Using Local Measurements and Numerical Weather Prediction Results, Bound.-Lay. Meteorol., 115, 223–239, http://dx.doi.org/10.1007/s10546-004-4422-8doi:10.1007/s10546-004-4422-8, 2005. O'Brien, L. M., Harris, N. R. P., Robinson, A. D., Gostlow, B., Warwick, N., Yang, X., and Pyle, J. A.: Bromocarbons in the tropical marine boundary layer at the Cape Verde Observatory – measurements and modelling, Atmos. Chem. Phys., 9, 9083–9099, http://dx.doi.org/10.5194/acp-9-9083-2009doi:10.5194/acp-9-9083-2009, 2009. Park, S., Jiménez, R., Daube, B. C., Pfister, L., Conway, T. J., Gottlieb, E. W., Chow, V. Y., Curran, D. J., Matross, D. M., Bright, A., Atlas, E. L., Bui, T. P., Gao, R.-S., Twohy, C. H., and Wofsy, S. C.: The CO<sub>2</sub> tracer clock for the Tropical Tropopause Layer, Atmos. Chem. Phys., 7, 3989–4000, http://dx.doi.org/10.5194/acp-7-3989-2007doi:10.5194/acp-7-3989-2007, 2007. Park, S., Atlas, E. L., Jiménez, R., Daube, B. C., Gottlieb, E. W., Nan, J., Jones, D. B. A., Pfister, L., Conway, T. J., Bui, T. P., Gao, R.-S., and Wofsy, S. C.: Vertical transport rates and concentrations of OH and Cl radicals in the Tropical Tropopause Layer from observations of CO<sub>2</sub> and halocarbons: implications for distributions of long- and short-lived chemical species, Atmos. Chem. Phys., 10, 6669–6684, http://dx.doi.org/10.5194/acp-10-6669-2010doi:10.5194/acp-10-6669-2010, 2010. Paul, C. and Pohnert, G.: Production and role of volatile halogenated compounds from marine algae, Natural Product Reports, 28, 186–195, 2011. Pfister, L., Selkirk, H B., Starr, D O., Rosenlof, K., and Newman, P A.: A meteorological overview of the TC4 mission, J. Geophys. Res., 115, D00J12, http://dx.doi.org/10.1029/2009JD013316doi:10.1029/2009JD013316, 2010. Pisso, I., Haynes, P. H., and Law, K. S.: Emission location dependent ozone depletion potentials for very short-lived halogenated species, Atmos. Chem. Phys., 10, 12025–12036, http://dx.doi.org/10.5194/acp-10-12025-2010doi:10.5194/acp-10-12025-2010, 2010. Pyle, J. A., Ashfold, M. J., Harris, N. R. P., Robinson, A. D., Warwick, N. J., Carver, G. D., Gostlow, B., O'Brien, L. M., Manning, A. J., Phang, S. M., Yong, S. E., Leong, K. P., Ung, E. H., and Ong, S.: Bromoform in the tropical boundary layer of the Maritime Continent during OP3, Atmos. Chem. Phys., 11, 529–542, http://dx.doi.org/10.5194/acp-11-529-2011doi:10.5194/acp-11-529-2011, 2011. Quack, B. and Wallace, D. W R.: Air-sea flux of bromoform: Controls, rates, and implications, Global Biogeochem. Cy., 17, 1023, http://dx.doi.org/10.1029/2002GB001890doi:10.1029/2002GB001890, 2003. Salawitch, R J., Weisenstein, D K., Kovalenko, L J., Sioris, C E., Wennberg, P O., Chance, K., Ko, M. K W., and McLinden, C A.: Sensitivity of ozone to bromine in the lower stratosphere, Geophys. Res. Lett., 32, L05811, http://dx.doi.org/10.1029/2004GL021504doi:10.1029/2004GL021504, 2005. Schauffler, S M., Atlas, E L., Blake, D R., Flocke, F., Lueb, R A., Lee-Taylor, J M., Stroud, V., and Travnicek, W.: Distributions of brominated organic compounds in the troposphere and lower stratosphere, J. Geophys. Res.-Atmos., 104, 21513–21535, 1999. Schofield, R., Fueglistaler, S., Wohltmann, I., and Rex, M.: Sensitivity of stratospheric Br$_\texty$ to uncertainties in very short lived substance emissions and atmospheric transport, Atmos. Chem. Phys., 11, 1379–1392, http://dx.doi.org/10.5194/acp-11-1379-2011doi:10.5194/acp-11-1379-2011, 2011. Toon, O B., Starr, D O., Jensen, E J., Newman, P A., Platnick, S., Schoeberl, M R., Wennberg, P O., Wofsy, S C., Kurylo, M J., Maring, H., Jucks, K W., Craig, M S., Vasques, M F., Pfister, L., Rosenlof, K H., Selkirk, H B., Colarco, P R., Kawa, S R., Mace, G G., Minnis, P., and Pickering, K E.: Planning, implementation, and first results of the Tropical Composition, Cloud and Climate Coupling Experiment (TC4), J. Geophys. Res., 115, D00J04, http://dx.doi.org/10.1029/2009JD013073doi:10.1029/2009JD013073, 2010. Tost, H., Lawrence, M. G., Brühl, C., Jöckel, P., The GABRIEL Team, and The SCOUT-O3-DARWIN/ACTIVE Team: Uncertainties in atmospheric chemistry modelling due to convection parameterisations and subsequent scavenging, Atmos. Chem. Phys., 10, 1931–1951, http://dx.doi.org/10.5194/acp-10-1931-2010doi:10.5194/acp-10-1931-2010, 2010. Warwick, N J., Pyle, J A., Carver, G D., Yang, X., Savage, N H., O'Connor, F M., and Cox, R A.: Global modeling of biogenic bromocarbons, J. Geophys. Res.-Atmos., 111, D24305, http://dx.doi.org/10.1029/2006JD007264doi:10.1029/2006JD007264, 2006. Yokouchi, Y., Hasebe, F., Fujiwara, M., Takashima, H., Shiotani, M., Nishi, N., Kanaya, Y., Hashimoto, S., Fraser, P., Toom-Sauntry, D., Mukai, H., and Nojiri, Y.: Correlations and emission ratios among bromoform, dibromochloromethane, and dibromomethane in the atmosphere, J. Geophys. Res.-Atmos., 110, D23309, http://dx.doi.org/10.1029/2005JD006303doi:10.1029/2005JD006303, 2005. Yung, Y L., Pinto, J P., Watson, R T., and Sander, S P.: Atmospheric Bromine And Ozone Perturbations In The Lower Stratosphere, J. Atmos. Sci., 37, 339–353, 1980. Zhou, Y., Mao, H T., Russo, R S., Blake, D R., Wingenter, O W., Haase, K B., Ambrose, J., Varner, R K., Talbot, R., and Sive, B C.: Bromoform and dibromomethane measurements in the seacoast region of New Hampshire, 2002–2004, J. Geophys. Res.-Atmos., 113, D08305, http://dx.doi.org/10.1029/2007JD009103doi:10.1029/2007JD009103, 2008.