ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-12-4185-2012 Climatological perspectives of air transport from atmospheric boundary layer to tropopause layer over Asian monsoon regions during boreal summer inferred from Lagrangian approach Chen B. 1 Xu X. D. 1 Yang S. 2 Zhao T. L. 3 State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China Laboratory of Cloud-Precipitation Physics and Severe Storms (LACS), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China Key Laboratory for Atmospheric Physics and Environment CMA-Nanjing University of Information Science & Technology, Nanjing, Jiangsu, 210044, China 06 02 2012 12 2 4185 4219 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-discuss.net/12/4185/2012/acpd-12-4185-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/12/4185/2012/acpd-12-4185-2012.pdf

The Asian Summer Monsoon (ASM) region has been recognized as a key region that plays a vital role in troposphere-to-stratosphere transport (TST), which can significantly impact the budget of global atmospheric constituents and climate change. However, the details of transport from the boundary layer (BL) to tropopause layer (TL) over this region, particularly from a climatological perspective, remains an issue of uncertainty. In this study, we present the climatological properties of BL-to-TL transport over the ASM region during boreal summer season (June-July-August) from 2001 to 2009. A comprehensive tracking analysis is conducted based on a large ensemble of TST-trajectories departing from the atmospheric BL and arriving at TL. Driven by the winds fields from the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) Global Forecast System, all TST-trajectories are selected from the high resolution datasets generated by the Lagrangian particle transport model FLEXPART using a domain-filling technique. Three key atmospheric boundary layer sources for BL-to-TL transport are identified with their contributions: (i) 38% from the region between tropical Western Pacific region and South China Seas (WP), (ii) 21% from Bay of Bengal and South Asian subcontinent (BOB), and (iii) 12% from the Tibetan Plateau, which includes the South Slope of the Himalayas (TIB). Controlled by the different patterns of atmospheric circulation, the air masses originating from these three source regions are transported along the different tracks into the TL. The spatial distributions of these three source regions remain similarly from year to year. The timescales of transport from BL to TL by the large-scale ascents range from 1 to 7 weeks, contributing up to 60–70% of the overall TST; whereas the transport governed by the deep convection overshooting becomes faster, with timescales of 1–2 days and contributions of 20–30%. These results provide clear policy implications for the control of very short lived substances, especially for the source regions over the Indian subcontinent with increasing populations and developing industries.

 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. %%ok Baker,~A K., Schuck,~T J., Slemr,~F., van Velthoven,~P., Zahn,~A., and Brenninkmeijer,~C A M.: Characterization of non-methane hydrocarbons in Asian summer monsoon outflow observed by the CARIBIC aircraft, Atmos. Chem. Phys., 11, 503–518, http://dx.doi.org/10.5194/acp-11-503-2011doi:10.5194/acp-11-503-2011, 2011. %%ok Bannister,~R N., O'Neill,~A., Gregory,~A R., and Nissen,~K M.: The role of the south-east Asian monsoon and other seasonal features in creating the \squttape-recorder signal in the Unified Model, Q. J. Roy. Meteor. Soc., 130, 1531–1554, http://dx.doi.org/10.1256/qj.03.106doi:10.1256/qj.03.106, 2004. Barret,~B., Ricaud,~P., Mari,~C., Attié,~J.-L., Bousserez,~N., Josse,~B., Le Flochmo\"en,~E., Livesey,~N J., Massart,~S., Peuch,~V.-H., Piacentini,~A., Sauvage,~B., Thouret,~V., and Cammas,~J.-P.: Transport pathways of CO in the African upper troposphere during the monsoon season: a study based upon the assimilation of spaceborne observations, Atmos. Chem. Phys., 8, 3231–3246, http://dx.doi.org/10.5194/acp-8-3231-2008doi:10.5194/acp-8-3231-2008, 2008. %%ok Berthet,~G., Esler,~J G., and Haynes,~P H.: A~Lagrangian perspective of the tropopause and the ventilation of the lowermost stratosphere, J. Geophys. Res., 112, D18102, http://dx.doi.org/10.1029/2006jd008295doi:10.1029/2006jd008295, 2007. Brewer,~A W.: Evidence for a~world circulation provided by the measurements of helium and water vapour distribution in the stratosphere, Q. J. Roy. Meteor. Soc., 75, 351–363, http://dx.doi.org/10.1002/qj.49707532603doi:10.1002/qj.49707532603, 1949. Chen,~B., Xu,~X D., Bian,~J C., and Shi,~X H.: Irreversible stratosphere-troposphere mass exchange characteristics over the Asian summer monsoon region, Chinese J. Geophys.-Ch., 53, 1050–1059, http://dx.doi.org/10.3969/j.issn.0001-5733.2010.05.005doi:10.3969/j.issn.0001-5733.2010.05.005, 2010. Chen,~Y., Zhou,~R., Shi,~C., and Bi,~Y.: Study on the trace species in the stratosphere and their impact on climate, Adv. Atmos. Sci., 23, 1020–1039, http://dx.doi.org/10.1007/s00376-006-1020-3doi:10.1007/s00376-006-1020-3, 2006. Clain,~G., Baray,~J L., Delmas,~R., Keckhut,~P., and Cammas,~J P.: A~lagrangian approach to analyse the tropospheric ozone climatology in the tropics: climatology of stratosphere-troposphere exchange at Reunion Island, Atmos. Environ., 44, 968–975, http://dx.doi.org/10.1016/j.atmosenv.2009.08.048doi:10.1016/j.atmosenv.2009.08.048, 2010. Corti,~T., Luo,~B P., de Reus,~M., Brunner,~D., Cairo,~F., Mahoney,~M J., Martucci,~G., Matthey,~R., Mitev,~V., dos Santos,~F H., Schiller,~C., Shur,~G., Sitnikov,~N M., Spelten,~N., Vössing,~H J., Borrmann,~S., and Peter,~T.: Unprecedented evidence for deep convection hydrating the tropical stratosphere, Geophys. Res. Lett., 35, L10810, http://dx.doi.org/10.1029/2008gl033641doi:10.1029/2008gl033641, 2008. Dessler,~A E. and Sherwood,~S C.: Effect of convection on the summertime extratropical lower stratosphere, J. Geophys. Res., 109, D23301, http://dx.doi.org/10.1029/2004jd005209doi:10.1029/2004jd005209, 2004. Dethof,~A., O'Neill,~A., Slingo,~J M., and Smit,~H G J.: A~mechanism for moistening the lower stratosphere involving the Asian summer monsoon, Q. J. Roy. Meteor. Soc., 125, 1079–1106, 1999. Devasthale,~A. and Fueglistaler,~S.: A climatological perspective of deep convection penetrating the TTL during the Indian summer monsoon from the AVHRR and MODIS instruments, Atmos. Chem. Phys., 10, 4573–4582, http://dx.doi.org/10.5194/acp-10-4573-2010doi:10.5194/acp-10-4573-2010, 2010. %%%ok Duflot,~V., Dils,~B., Baray,~J L., De Mazière,~M., Attié,~J L., Vanhaelewyn,~G., Senten,~C., Vigouroux,~C., Clain,~G., and Delmas,~R.: Analysis of the origin of the distribution of CO in the subtropical Southern Indian Ocean in 2007, J. Geophys. Res., 115, D22106, http://dx.doi.org/10.1029/2010jd013994doi:10.1029/2010jd013994, 2010. Fierli,~F., Orlandi,~E., Law,~K S., Cagnazzo,~C., Cairo,~F., Schiller,~C., Borrmann,~S., Di Donfrancesco,~G., Ravegnani,~F., and Volk,~C M.: Impact of deep convection in the tropical tropopause layer in West Africa: in-situ observations and mesoscale modelling, Atmos. Chem. Phys., 11, 201–214, http://dx.doi.org/10.5194/acp-11-201-2011doi:10.5194/acp-11-201-2011, 2011. %%ok Forster,~C., Stohl,~A., and Seibert,~P.: Parameterization of Convective Transport in a~Lagrangian Particle Dispersion Model and Its Evaluation, J. Appl. Meteorol. Clim., 46, 403–422, http://dx.doi.org/10.1175/jam2470.1doi:10.1175/jam2470.1, 2007. Forster de~F.,~P M. and Shine,~K P.: Stratospheric water vapour changes as a~possible contributor to observed stratospheric cooling, Geophys. Res. Lett., 26, 3309–3312, http://dx.doi.org/10.1029/1999gl010487doi:10.1029/1999gl010487, 1999. Fu,~R., Hu,~Y L., Wright,~J S., Jiang,~J H., Dickinson,~R E., Chen,~M X., Filipiak,~M., Read,~W G., Waters,~J W., and Wu,~D L.: Short circuit of water vapor and polluted air to the global stratosphere by convective transport over the Tibetan Plateau, P. Natl. Acad. Sci. USA, 103, 5664–5669, http://dx.doi.org/10.1073/pnas.0601584103doi:10.1073/pnas.0601584103, 2006. Fueglistaler,~S., Wernli,~H., and Peter,~T.: Tropical troposphere-to-stratosphere transport inferred from trajectory calculations, J. Geophys. Res., 109, D03108, http://dx.doi.org/10.1029/2003jd004069doi:10.1029/2003jd004069, 2004. Fueglistaler,~S., Bonazzola,~M., Haynes,~P H., and Peter,~T.: Stratospheric water vapor predicted from the Lagrangian temperature history of air entering the stratosphere in the tropics, J. Geophys. Res., 110, D08107, http://dx.doi.org/10.1029/2004jd005516doi:10.1029/2004jd005516, 2005. Gettelman,~A., Kinnison,~D E., Dunkerton,~T J., and Brasseur,~G P.: Impact of monsoon circulations on the upper troposphere and lower stratosphere, J. Geophys. Res., 109, D22101, http://dx.doi.org/10.1029/2004jd004878doi:10.1029/2004jd004878, 2004. He,~H., Tarasick,~D W., Hocking,~W K., Carey-Smith,~T K., Rochon,~Y., Zhang,~J., Makar,~P A., Osman,~M., Brook,~J., Moran,~M D., Jones,~D B A., Mihele,~C., Wei,~J C., Osterman,~G., Argall,~P S., McConnell,~J., and Bourqui,~M S.: Transport analysis of ozone enhancement in Southern Ontario during BAQS-Met, Atmos. Chem. Phys., 11, 2569–2583, http://dx.doi.org/10.5194/acp-11-2569-2011doi:10.5194/acp-11-2569-2011, 2011. %%ok Hirdman,~D., Sodemann,~H., Eckhardt,~S., Burkhart,~J F., Jefferson,~A., Mefford,~T., Quinn,~P K., Sharma,~S., Ström,~J., and Stohl,~A.: Source identification of short-lived air pollutants in the Arctic using statistical analysis of measurement data and particle dispersion model output, Atmos. Chem. Phys., 10, 669–693, http://dx.doi.org/10.5194/acp-10-669-2010doi:10.5194/acp-10-669-2010, 2010. %%ok Holton,~J R. and Gettelman,~A.: Horizontal transport and the dehydration of the stratosphere, Geophys. Res. Lett., 28, 2799–2802, http://dx.doi.org/10.1029/2001gl013148doi:10.1029/2001gl013148, 2001. Holton, J. R., Haynes, P. H., McIntyre, M. E., Douglass, A. R., Rood, R. B., and Pfister, L.: Stratosphere-troposphere exchange, Rev. Geophys., 33, 403–439, http://dx.doi.org/10.1029/95rg02097doi:10.1029/95rg02097, 1995. Hoor,~P., Wernli,~H., Hegglin,~M I., and Bönisch,~H.: Transport timescales and tracer properties in the extratropical UTLS, Atmos. Chem. Phys., 10, 7929–7944, http://dx.doi.org/10.5194/acp-10-7929-2010doi:10.5194/acp-10-7929-2010, 2010. Jacob,~D J. and Winner,~D A.: Effect of climate change on air quality, Atmos. Environ., 43, 51–63, http://dx.doi.org/10.1016/j.atmosenv.2008.09.051doi:10.1016/j.atmosenv.2008.09.051, 2009. James,~P., Stohl,~A., Forster,~C., Eckhardt,~S., Seibert,~P., and Frank,~A.: A~15-year climatology of stratosphere-troposphere exchange with a~Lagrangian particle dispersion model: 1. Methodology and validation, J. Geophys. Res., 108, 8519, http://dx.doi.org/10.1029/2002jd002637doi:10.1029/2002jd002637, 2003. James,~R., Bonazzola,~M., Legras,~B., Surbled,~K., and Fueglistaler,~S.: Water vapor transport and dehydration above convective outflow during Asian monsoon, Geophys. Res. Lett., 35, L20810, http://dx.doi.org/10.1029/2008gl035441doi:10.1029/2008gl035441, 2008. Jiang,~J H., Livesey,~N J., Su,~H., Neary,~L., McConnell,~J C., and Richards,~N A D.: Connecting surface emissions, convective uplifting, and long-range transport of carbon monoxide in the upper troposphere: new observations from the Aura Microwave Limb Sounder, Geophys. Res. Lett., 34, L18812, http://dx.doi.org/10.1029/2007gl030638doi:10.1029/2007gl030638, 2007. Johnson,~D., Jucks,~K., Traub,~W., and Chance,~K.: Isotopic composition of stratospheric water vapor: implications for transport, J. Geophys. Res., 106, 12219–12226, 2001. Knippertz,~P. and Wernli,~H.: A~Lagrangian Climatology of Tropical Moisture Exports to the Northern Hemispheric Extratropics, J. Climate, 23, 987–1003, 2010. Kubokawa,~H., Fujiwara,~M., Nasuno,~T., and Satoh,~M.: Analysis of the tropical tropopause layer using the Nonhydrostatic Icosahedral Atmospheric Model (NICAM): aqua planet experiments, J. Geophys. Res., 115, D08102, http://dx.doi.org/10.1029/2009jd012686doi:10.1029/2009jd012686, 2010. Law,~K S., Fierli,~F., Cairo,~F., Schlager,~H., Borrmann,~S., Streibel,~M., Real,~E., Kunkel,~D., Schiller,~C., Ravegnani,~F., Ulanovsky,~A., D'Amato,~F., Viciani,~S., and Volk,~C M.: Air mass origins influencing TTL chemical composition over West Africa during 2006 summer monsoon, Atmos. Chem. Phys., 10, 10753–10770, http://dx.doi.org/10.5194/acp-10-10753-2010doi:10.5194/acp-10-10753-2010, 2010. %%ok Lawrence,~M G.: Atmospheric science: Asia under a~high-level brown cloud, Nat. Geosci., 4, 352–353, 2011. Lawrence,~M G. and Lelieveld,~J.: Atmospheric pollutant outflow from southern Asia: a review, Atmos. Chem. Phys., 10, 11017–11096, http://dx.doi.org/10.5194/acp-10-11017-2010doi:10.5194/acp-10-11017-2010, 2010. %%ok 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., 112, D04308, http://dx.doi.org/10.1029/2005jd006940doi:10.1029/2005jd006940, 2007. Li,~Q B., Jiang,~J H., Wu,~D L., Read,~W G., Livesey,~N J., Waters,~J W., Zhang,~Y S., Wang,~B., Filipiak,~M J., Davis,~C P., Turquety,~S., Wu,~S L., Park,~R J., Yantosca,~R M., and Jacob,~D J.: Convective outflow of South Asian pollution: a~global CTM simulation compared with EOS MLS observations, Geophys. Res. Lett., 32, L14826, http://dx.doi.org/10.1029/2005gl022762doi:10.1029/2005gl022762, 2005. Liu,~X., Penner,~J E., and Herzog,~M.: Global modeling of aerosol dynamics: model description, evaluation, and interactions between sulfate and nonsulfate aerosols, J. Geophys. Res., 110, 1–37, 2005. Oltmans,~S., Johnson,~B., Harris,~J., Vömel,~H., Thompson,~A., Koshy,~K., Simon,~P., Bendura,~R., Logan,~J., Hasebe,~F., Shiotani,~M., Kirchhoff,~V., Maata,~M., Sami,~G., Samad,~A., Tabuadravu,~J., Enriquez,~H., Agama,~M., Cornejo,~J., and Paredes,~F.: Ozone in the Pacific tropical troposphere from ozonesonde observations, J. Geophys. Res., 106, 32503–32525, 2001. Pan,~L L., Bowman,~K P., Atlas,~E L., Wofsy,~S C., Zhang,~F., Bresch,~J F., Ridley,~B A., Pittman,~J V., Homeyer,~C R., Romashkin,~P., and Cooper,~W A.: The Stratosphere-Troposphere Analyses of Regional Transport 2008 Experiment, B. Am. Meteorol. Soc., 91, 327–342, http://dx.doi.org/10.1175/2009bams2865.1doi:10.1175/2009bams2865.1, 2010. Paris,~J.-D., Stohl,~A., Ciais,~P., Nédélec,~P., Belan,~B D., Arshinov,~M. Yu., and Ramonet,~M.: Source-receptor relationships for airborne measurements of CO<sub>2</sub>, CO and O<sub>3</sub> above Siberia: a cluster-based approach, Atmos. Chem. Phys., 10, 1671–1687, http://dx.doi.org/10.5194/acp-10-1671-2010doi:10.5194/acp-10-1671-2010, 2010. %%ok Park,~M., Randel,~W J., Gettelman,~A., Massie,~S T., and Jiang,~J H.: Transport above the Asian summer monsoon anticyclone inferred from Aura Microwave Limb Sounder tracers, J. Geophys. Res., 112, D16309, http://dx.doi.org/10.1029/2006jd008294doi:10.1029/2006jd008294, 2007. Park,~M., Randel,~W J., Emmons,~L K., Bernath,~P F., Walker,~K A., and Boone,~C D.: Chemical isolation in the Asian monsoon anticyclone observed in Atmospheric Chemistry Experiment (ACE-FTS) data, Atmos. Chem. Phys., 8, 757–764, http://dx.doi.org/10.5194/acp-8-757-2008doi:10.5194/acp-8-757-2008, 2008. %%ok Park,~M., Randel,~W J., Emmons,~L K., and Livesey,~N J.: Transport pathways of carbon monoxide in the Asian summer monsoon diagnosed from Model of Ozone and Related Tracers (MOZART), J. Geophys. Res., 114, D08303, http://dx.doi.org/10.1029/2008jd010621doi:10.1029/2008jd010621, 2009. Plumb,~R A.: A \quttropical pipe model of stratospheric transport, J. Geophys. Res., 101, 3957–3972, http://dx.doi.org/10.1029/95jd03002doi:10.1029/95jd03002, 1996. Randel, W. J. and Park, M.: Deep convective influence on the Asian summer monsoon anticyclone and associated tracer variability observed with Atmospheric Infrared Sounder (AIRS), J. Geophys. Res., 111, D12314, http://dx.doi.org/10.1029/2005jd006490doi:10.1029/2005jd006490, 2006. Randel,~W J., Park,~M., Emmons,~L., Kinnison,~D., Bernath,~P., Walker,~K A., Boone,~C., and Pumphrey,~H.: Asian monsoon transport of pollution to the stratosphere, Science, 328, 611–613, http://dx.doi.org/10.1126/science.1182274doi:10.1126/science.1182274, 2010. Ryoo,~J.-M., Waliser,~D E., and Fetzer,~E J.: Trajectory analysis on the origin of air mass and moisture associated with Atmospheric Rivers over the west coast of the United States, Atmos. Chem. Phys. Discuss., 11, 11109–11142, http://dx.doi.org/10.5194/acpd-11-11109-2011doi:10.5194/acpd-11-11109-2011, 2011. %%ok Schiller,~C., Grooß,~J.-U., Konopka,~P., Plöger,~F., Silva dos Santos,~F H., and Spelten,~N.: Hydration and dehydration at the tropical tropopause, Atmos. Chem. Phys., 9, 9647–9660, http://dx.doi.org/10.5194/acp-9-9647-2009doi:10.5194/acp-9-9647-2009, 2009. %%ok Schmale,~J., Schneider,~J., Ancellet,~G., Quennehen,~B., Stohl,~A., Sodemann,~H., Burkhart,~J F., Hamburger,~T., Arnold,~S R., Schwarzenboeck,~A., Borrmann,~S., and Law,~K S.: Source identification and airborne chemical characterisation of aerosol pollution from long-range transport over Greenland during POLARCAT summer campaign 2008, Atmos. Chem. Phys., 11, 10097–10123, http://dx.doi.org/10.5194/acp-11-10097-2011doi:10.5194/acp-11-10097-2011, 2011. %%ok Sinnhuber,~B.-M. and Folkins,~I.: Estimating the contribution of bromoform to stratospheric bromine and its relation to dehydration in the tropical tropopause layer, Atmos. Chem. Phys., 6, 4755–4761, http://dx.doi.org/10.5194/acp-6-4755-2006doi:10.5194/acp-6-4755-2006, 2006. %%ok Solomon,~S., Rosenlof,~K H., Portmann,~R W., Daniel,~J S., Davis,~S M., Sanford,~T J., and Plattner,~G.-K.: Contributions of stratospheric water vapor to decadal changes in the rate of global warming, Science, 327, 1219–1223, http://dx.doi.org/10.1126/science.1182488doi:10.1126/science.1182488, 2010. Stohl,~A. and James,~P.: A~Lagrangian analysis of the atmospheric branch of the global water cycle. Part I: Method description, validation, and demonstration for the August 2002 flooding in central Europe, J. Hydrometeorol., 5, 656–678, 2004. Stohl,~A. and Sodemann,~H.: Characteristics of atmospheric transport into the Antarctic troposphere, J. Geophys. Res., 115, D02305, http://dx.doi.org/10.1029/2009JD012536doi:10.1029/2009JD012536, 2010. Stohl,~A., Bonasoni,~P., Cristofanelli,~P., Collins,~W., Feichter,~J., Frank,~A., Forster,~C., Gerasopoulos,~E., Gäggeler,~H., James,~P., Kentarchos,~T., Kromp-Kolb,~H., Krüger,~B., Land,~C., Meloen,~J., Papayannis,~A., Priller,~A., Seibert,~P., Sprenger,~M., Roelofs,~G J., Scheel,~H E., Schnabel,~C., Siegmund,~P., Tobler,~L., Trickl,~T., Wernli,~H., Wirth,~V., Zanis,~P., and Zerefos,~C.: Stratosphere-troposphere exchange: a~review, and what we have learned from STACCATO, J. Geophys. Res., 108, 8516, http://dx.doi.org/10.1029/2002jd002490doi:10.1029/2002jd002490, 2003. Stohl,~A., Forster,~C., Frank,~A., Seibert,~P., and Wotawa,~G.: Technical note: The Lagrangian particle dispersion model FLEXPART version 6.2, Atmos. Chem. Phys., 5, 2461–2474, http://dx.doi.org/10.5194/acp-5-2461-2005doi:10.5194/acp-5-2461-2005, 2005. %%ok Su,~H., Jiang,~J H., Liu,~X., Penner,~J E., Read,~W G., Massie,~S., Schoeberl,~M R., Colarco,~P., Livesey,~N J., and Santee,~M L.: Observed increase of TTL temperature and water vapor in polluted clouds over Asia, J. Climate, 24, 2728–2736, http://dx.doi.org/10.1175/2010jcli3749.1doi:10.1175/2010jcli3749.1, 2011. Tian,~W., Chipperfield,~M., and Huang,~Q.: Effects of the Tibetan Plateau on total column ozone distribution, Tellus B, 60, 622–635, http://dx.doi.org/10.1111/j.1600-0889.2008.00338.xdoi:10.1111/j.1600-0889.2008.00338.x, 2008. Tzella,~A. and Legras,~B.: A Lagrangian view of convective sources for transport of air across the Tropical Tropopause Layer: distribution, times and the radiative influence of clouds, Atmos. Chem. Phys., 11, 12517–12534, http://dx.doi.org/10.5194/acp-11-12517-2011doi:10.5194/acp-11-12517-2011, 2011. %%ok Vogel,~B., Pan,~L L., Konopka,~P., Günther,~G., Müller,~R., Hall,~W., Campos,~T., Pollack,~I., Weinheimer,~A., Wei,~J., Atlas,~E L., and Bowman,~K P.: Transport pathways and signatures of mixing in the extratropical tropopause region derived from Lagrangian model simulations, J. Geophys. Res., 116, D05306, http://dx.doi.org/10.1029/2010jd014876doi:10.1029/2010jd014876, 2011. Werner,~A., Volk,~C M., Ivanova,~E V., Wetter,~T., Schiller,~C., Schlager,~H., and Konopka,~P.: Quantifying transport into the Arctic lowermost stratosphere, Atmos. Chem. Phys., 10, 11623–11639, http://dx.doi.org/10.5194/acp-10-11623-2010doi:10.5194/acp-10-11623-2010, 2010. %%ok Wright,~J S., Fu,~R., Fueglistaler,~S., Liu,~Y S., and Zhang,~Y.: The influence of summertime convection over Southeast Asia on water vapor in the tropical stratosphere, J. Geophys. Res., 116, D12302, http://dx.doi.org/10.1029/2010jd015416doi:10.1029/2010jd015416, 2011.