Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 9 18 2009 10.5194/acp-9-6775-2009 http://www.atmos-chem-phys.net/9/6775/2009/ http://www.atmos-chem-phys.net/9/6775/2009/acp-9-6775-2009.html http://www.atmos-chem-phys.net/9/6775/2009/acp-9-6775-2009.pdf 6775 6792 2009-09-18 Evidence for ice particles in the tropical stratosphere from in-situ measurements M. de Reus S. Borrmann stephan.borrmann@mpic.de A. Bansemer A. J. Heymsfield R. Weigel C. Schiller V. Mitev W. Frey D. Kunkel A. Kürten J. Curtius N. M. Sitnikov A. Ulanovsky F. Ravegnani Max Planck Institute for Chemistry, Particle Chemistry Department, Mainz, Germany Institute for Atmospheric Physics, Mainz University, Germany National Center for Atmospheric Research, Boulder, USA Institute of Chemistry and Dynamics of the Geosphere, Research Centre Jülich, Germany Swiss Centre for Electronics and Microtechnology, Neuchâtel, Switzerland Institute for Atmospheric and Environmental Sciences, Goethe University of Frankfurt, Germany Central Aerological Observatory, Dolgoprudny, Moskow Region, Russia Institute of Atmospheric Sciences and Climate, Bologna, Italy now at: Elementar Analysensysteme GmbH, Hanau, Germany In-situ ice crystal size distribution measurements are presented within the tropical troposphere and lower stratosphere. The measurements were performed using a combination of a Forward Scattering Spectrometer Probe (FSSP-100) and a Cloud Imaging Probe (CIP), which were installed on the Russian high altitude research aircraft M55 "Geophysica" during the SCOUT-O3 campaign in Darwin, Australia. One of the objectives of the campaign was to characterise the Hector convective system, which appears on an almost daily basis during the pre-monsoon season over the Tiwi Islands, north of Darwin. In total 90 encounters with ice clouds, between 10 and 19 km altitude were selected from the dataset and were analysed. Six of these encounters were observed in the lower stratosphere, up to 1.4 km above the local tropopause. Concurrent lidar measurements on board "Geophysica" indicate that these ice clouds were a result of overshooting convection. Large ice crystals, with a maximum dimension up to 400 μm, were observed in the stratosphere. The stratospheric ice clouds included an ice water content ranging from 7.7×10−5 to 8.5×10−4 g m−3 and were observed at ambient relative humidities (with respect to ice) between 75 and 157%. Three modal lognormal size distributions were fitted to the average size distributions for different potential temperature intervals, showing that the shape of the size distribution of the stratospheric ice clouds are similar to those observed in the upper troposphere. In the tropical troposphere the effective radius of the ice cloud particles decreases from 100 μm at about 10 km altitude, to 3 μm at the tropopause, while the ice water content decreases from 0.04 to 10−5 g m−3. No clear trend in the number concentration was observed with altitude, due to the thin and inhomogeneous characteristics of the observed cirrus clouds. The ice water content calculated from the observed ice crystal size distribution is compared to the ice water content derived from two hygrometer instruments. This independent measurement of the ice water content agrees within the combined uncertainty of the instruments for ice water contents exceeding 3×10−4g m−3. Stratospheric residence times, calculated based on gravitational settling, and evaporation rates show that the ice crystals observed in the stratosphere over the Hector storm system had a high potential of humidifying the stratosphere locally. Utilizing total aerosol number concentration measurements from a four channel condensation particle counter during two separate campaigns, it can be shown that the fraction of ice particles to the number of aerosol particles remaining ranges from 1:300 to 1:30 000 for tropical upper tropospheric ice clouds with ambient temperatures below −75°C. Baker, B. and Lawson, R. P.: Improvement in determination of ice water content from two-dimensional particle imagery, Part~I: image to mass relationships, J. Appl. Meteorol. Clim., 45, 1282–1290, 2006. Baumgardner, D, Dye, J. E., Gandrud, B. W., and Knollenberg, R. G.: Interpretation of measurements made by the forward scattering spectrometer probe (FSSP-300) during the airborne arctic stratospheric expedition, J. Geophys. Res., 97, 8035–8046, 1992. Baumgardner, D. and Korolev, A.: Airspeed corrections for optical array probe sample volumes, J. Atmos. Ocean. Tech., 14, 1224–1229, 1997. Borrmann, S., Solomon, S., Dye, J. E., and Luo, B.: The potential of cirrus clouds for heterogeneous chlorine activation, Geophys. Res. Lett., 23, 2133–2136, 1996. Borrmann, S., Luo, B., and Mishchenko, M.: The application of the T-matrix method to the measurement of aspherical particles with forward scattering optical particle counters, J. Aerosol Sci., 31, 789–799, 2000. Brunner, D., Siegmund, P., May, P. T., Chappel, L., Schiller, C., Müller, R., Peter, T., Fueglistaler, S., MacKenzie, A. R., Fix, A., Schlager, H., Allen, G., Fjaeraa, A. M., Streibel, M., and Harris, N. R. P.: The SCOUT-O3 Darwin Aircraft Campaign: rationale and meteorology, Atmos. Chem. Phys., 9, 93–117, 2009. Chaboureau, J.-P., Cammas, J.-P., Duron, J., Mascart, P. J., Sitnikov, N. M., and Voessing, H.-J.: A numerical study of \mboxtropical \mboxcross-tropopause transport by convective overshoots, Atmos. Chem. Phys., 7, 1731–1740, 2007. Chen, J. P., McFarquhar, G. M., Heymsfield, A. J., and Ramanathan, A. J..: A modelling and observational study of the detailed microphysical structure of tropical cirrus anvils, J. Geophys. Res., 102, 6637–6653, 1997. Connolly, P. J., Choularton, T. W., Gallagher, M. W., Bower, K. N., Flynn, M. J., and Whiteway, J. A.: Cloud-resolving simulations of intense tropical Hector thunderstorms: Implications for aerosol-cloud interactions, Q. J. Roy. Meteorol. Soc., 132, 3079–3106, 2006. 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 overshooting convection hydrating the tropical stratosphere, Geophys. Res. Lett., 35, L10810, doi:10.1029/2008GL033641, 2008. Curtius, J., Weigel, R., Vössing, H.-J., Wernli, H., Werner, A., Volk, C.-M., Konopka, P., Krebsbach, M., Schiller, C., Roiger, A., Schlager, H., Dreiling, V., and Borrmann, S.: Observations of meteoric material and implications for aerosol nucleation in the winter Arctic lower stratosphere derived from in situ particle measurements, Atmos. Chem. Phys., 5, 3053–3069, 2005. Curtius, J.: Nucleation of atmospheric aerosol particles, C. R. Physique, 7, 1027–1045, 2006. de Reus, M., Krejci, R., Williams, J., Fischer, H., Scheele, R., and Ström, J.: Vertical and horizontal distributions of the aerosol number concentration and size distribution over the northern Indian Ocean, J. Geophys. Res., 106, 28629–28641, 2001. Dye, J. E. and Baumgardner, D.: Evaluation of the Forward Scattering Spectrometer Probe, Part~I: Electronic and optical studies, J. Atmos. Ocean. Tech., 1, 329–344, 1984. Eremenko, M. N., Zasetsky, A. Y., Boone, C. D., and Sloan, J. J.: Properties of high-altitude tropical cirrus clouds determined from ACE FTS observations, Geophys. Res. Lett., 32, L15S07, doi:10.1029/2005GL022428, 2005. Field, P. R., Heymsfield, A. J., and Bansemer, A.: Shattering and particle interarrival times measured by optical array probes in ice clouds, J. Atmos. Ocean. Tech., 23, 1357–1371, 2006. Garrett, T. J., Gerber, H., Baumgardner, D. G., Twohy, C. H., and Weinstock, E. M.: Small, highly reflective ice crystals in low-latitude cirrus, Geophys. Res. Lett., 30, 2132, doi:10.1029/2003GL018153, 2003. Garrett, T. J., Dean-Day, J., Liu, C., Barnett, B., Mace, G., Baumgardner, D., Webster, C., Bui, T., Read, W., and Minnis, P.: Convective formation of pileus cloud near the tropopause, Atmos. Chem. Phys., 6, 1185–1200, 2006. Gayet, J. F., Ovarlez, J., Shcherbakov, V., Ström, J., Schumann, U., Minikin, A., Auriol, F., Petzold, A., and Monier, M.: Cirrus cloud microphysical and optical properties at southern and northern midlatitutes during the INCA Experiment, J. Geophys. Res., 109, D20206, doi:10.1029/2004JD004803, 2004. Grosvenor, D. P., Choularton, T. W., Coe, H., and Held, G.: A study of the effect of overshooting deep convection on the water content of the TTL and lower stratosphere from Cloud Resolving Model simulations, Atmos. Chem. Phys., 7, 4977–5002, 2007. Heymsfield, A. J., and Parrish, J. L.: A computational technique for increasing the effective sampling volume of the PMS \mboxtwo-dimensional particle size spectrometer, J. Appl. Meteorol., 17, 1566–1572, 1978. Heymsfield, A. J.: Ice particles observed in a cirriform cloud at −83°C and implications for polar stratospheric clouds, J. Atmos. Sci., 43, 851–855, 1986. Heymsfield, A. J. and McFarquhar, G. M.: Midlatitude and tropical cirrus – microphysical properties, in: Cirrus, edited by: Lynch, D. K., Sassen, K., Starr, D. O., and Stephens, G., Oxford Univ. Press, New York, 2002. Heymsfield, A. J., Schmidt, C., Bansemer, A., van Zadelhoff, G. J., McGill, M. J., Twohy, M. J., and Baumgardner, D.: Effective radius of ice cloud particle populations derived from aircraft probes, J. Atmos. Ocean. Tech., 23, 361–380, 2006. Heymsfield, A. J.: On measurements of small ice particles in clouds, Geophys. Res. Lett., 34, L23812, doi:10.1029/2007GL030951, 2007. Kärcher, B. and Lohmann, U.: A parameterization of cirrus cloud formation: Homogeneous freezing of supercooled aerosols, J. Geophys. Res., 107, 4010, doi:10.1029/2001JD000470, 2002. Knollenberg, R. G.: The optical array: an alternative to scattering or extinction for airborne particle size determination, J. Appl. Meteorol., 9, 86–103, 1970. Knollenberg, R. G., Kelly, K., and Wilson, J. C.: Measurements of high number densities of ice crystals in the tops of tropical cumulonimbus, J. Geophys. Res., 98, 8639–8664, 1993. Korolev, A. V., Strapp, J. W., and Isaac, G. A.: Evaluation of the accuracy of PMS Optical Array Probes, J. Atmos. Ocean. Tech., 15, 708–720, 1998. Korolev, A.: Reconstruction of the sizes of spherical particles from their shadow images, Part~I: Theoretical considerations, J. Atmos. Ocean. Tech., 24, 376–389, 2007. Krämer, M., and Afchine, A.: Sampling characteristics of inlets operated at low U/U0 ratios: new insights from computational fluid dynamics (CFX) modeling, J. Aerosol Sci., 35, 683–694, doi:10.1016/j.jaerosci.2003.11.011, 2004. Krämer, M., Schiller, C., Afchine, A., Bauer, R., Gensch, I., Mangold, A., Schlicht, S., Spelten, N., Sitnikov, N., Borrmann, S., de Reus, M., and Spichtinger, P.: Ice supersaturations and cirrus cloud crystal numbers, Atmos. Chem. Phys., 9, 3505–3522, 2009. Lee, S. H., Wilson, J. C., Baumgardner, D., Herman, R. L., Weinstock, E. M., LaFleur, B. G., Kok, G., Anderson, B., Lawson, P., Baker, B., Strawa, A., Pittman, J. V., Reeves, J. M., and Bui, T. P.: New particle formation observed in the tropical/subtropical cirrus clouds, J. Geophys. Res., 109, D20209, doi:10.1029/2004JD005033, 2004. Lynch, D. K., Sassen, K., Starr, D. O., and Stephens, G.: Cirrus, Oxford Univ. Press, New York, 2002. McFarquhar, G. M. and Heymsfield, A. J.: Parameterisation of tropical cirrus ice crystal size distributions and implications for radiative transfer: results from CEPEX, J. Atmos. Sci., 54, 2187–2200, 1997. McFarquhar, G. M. and Heymsfield, A. J.: The definition and significance of an effective radius for ice clouds, J. Atmos. Sci., 55, 2039–2052, 1998. McFarquhar, G. M., Heymsfield, A. J., Spinhirne, J., and Hart, B.: Thin and subvisual tropopause tropical cirrus: observations and radiative impacts, J. Atmos. Sci., 57, 1841–1853, 2000. McFarquhar, G. M., Um, J., Freer, M., Baumgardner, D., Kok, G. L., and Mace, G.: Importance of small ice crystals to cirrus properties: Observations from the tropical warm pool international cloud experiment (TWP-ICE), Geophys. Res. Lett., 34, L13803, doi:10.1029/2007GL029865, 2007. Mitchell, D. L. and Heymsfield, A. J.: Refinements in the Treatment of ice particle terminal velocities, highlighting aggregates, J. Atmos. Sci., 62, 1637–1644, 2005. Mitev, V., Matthey, R., and Makanov, V.: Miniature backscatter lidar for cloud and aerosol observation from high altitude aircraft, Rec. Res. Dev. Geophys., 4, 207–223, 2002. Nielsen, J. K., Larsen, N., Cairo, F., Di Donfrancesco, G., Rosen, J. M., Durry, G., Held, G., and Pommereau, J. P.: Solid particles in the tropical lowest stratosphere, Atmos. Chem. Phys., 7, 685–695, 2007. Oltmans, S. J., Vömel, H., Hofmann, D. J., Rosenlof, K. H., and Kley, D.: The increase in stratospheric water vapour from balloonborne, frostpoint hygrometer measurements at Washington D.C. and Boulder, Geophys. Res. Lett., 27, 3453–3456, 2000. Peter, Th., Luo, B. P., Wirth, M., Kiemle, C., Flentje, H., Yushkov, V. A., Khattatov, V., Rudakov, V., Thomas, A., Borrmann, S., Toci, G., Mazzinghi, P., Beuermann, J., Schiller, C., Cairo, F., Di Donfrancesco, G., Adriani, A., Volk, C. M., Strom, J., Noone, K., Mitev, V., MacKenzie, R. A., Carslaw, K. S., Trautmann, T., Santacesaria, V., and Stefanutti, L.: Ultrathin Tropical Tropopause Clouds (UTTCs): I, Cloud morphology and occurrence, Atmos. Chem. Phys., 3, 1083–1091, 2003. Pratte, P., van den Bergh, H., and Rossi, M. J.: The kinetics of H2O vapor condensation and evaporation on different types of ice in the range 130–210 K, J. Phys. Chem. A, 110, 3042–3058, 2006. Schiller, C., Krämer, M., Afchine, A., Spelten, N., and Sitnikov, N.: The ice water content of Arctic, mid latitude and tropical cirrus, J. Geophys. Res., 113, D24208, doi:10.1029/2008JD010342, 2008. Schröder, F., Kärcher, B., Duroure, C., Ström, J., Petzold, A., Gayet, J. F., Strauss, B., Wendling, P., and Borrmann, S.: On the transition of contrails into cirrus clouds, J. Atmos. Sci., 57, 464–480, 2000. Seifert, M., Ström, J., Krejci, R., Minikin, A., Petzold, A., Gayet, J.-F., Schlager, H., Ziereis, H., Schumann, U., and Ovarlez, J.: Aerosol-cirrus interactions: a number based phenomenon at all?, Atmos. Chem. Phys., 4, 293–305, 2004. Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics: from air pollution to climate change, John Wiley and Sons, Hoboken, NJ, 2006. Sherwood, S. C. and Dessler, A. E.: A Model for transport across the tropical tropopause, J. Atmos. Sci., 58, 765–779, 2001. Sitnikov, N. M., Yushkov, V. A., Afchine, A. A., Korshunov, L. I., Astakov, V. I., Ulanovskii, A. E., Krämer, M., Mangold, A., Schiller, C., and Ravegnani, F.: The FLASH instrument for water vapor measurements on board the high altitude airplane, Instruments and Experimental Techniques, 50, 113–121, 2007. Solomon, S., Borrmann, S., Garcia, R. R., Portmann, R., Thomason, L., Poole, L. R., Winkler, D., and McCormick, M. P.: Heterogeneous chlorine chemistry in the tropopause region, J. Geophys. Res., 102, 21411–21429, 1997. Stephens, G. L. and Webster, P. J.: Clouds and climate: sensitivity of simple systems, J. Atmos. Sci., 38, 235–247, 1981. Strapp, J. W., Albers, F., Reuter, A., Korolev, A. V., Maixner, U., Rashke, E., and Vukovic, Z.: Laboratory measurements of the response of a PMS~OAP-2DC, J. Atmos. Ocean. Tech., 18, 1150–1170, 2001. Ström, J., Strauss, B., Anderson, T., Schröder, F., Heintzenberg, J., and Wendling, P.: In-situ observations of the microphysical properties of young cirrus clouds, J. Atmos. Sci., 54, 2542–2553, 1997. Thomas, A., Borrmann, S., Kiemle, C., Cairo, F., Volk, M., Beuermann, J., Lepuchov, B., Santacesaria, V., Matthey, R., Rudakov, V., Yushkov, V., MacKenzie, A. R., and Stefanutti, L.: In-situ measurements of background aerosol and subvisible cirrus in the tropical tropopause region, J. Geophys. Res., 107, 4763, doi:10.1029/2001JD001385, 2002. Vaughan, G., Schiller, C., MacKenzie, A. R., Bower, K., Peter, T., Schlager, H., Harris, N. R. P., and May, P. T.: SCOUT-O3/ACTIVE high-altitude aircraft measurements around deep tropical convection, B. Am. Meteorol. Soc., 89, 647–662, 2008. Voigt, C., Schlager, H., Ziereis, H., Kärcher, B., Luo, B. P., Schiller, C., Krämer, M., Popp, P. J., Irie, H., and Kondo, Y.: Nitric acid uptake in cirrus clouds, Geophys. Res. Lett., 33, L05803, doi:10.1029/2005GL025159, 2006. Weigel, R., Hermann, M., Curtius, J., Voigt, C., Walter, S., Böttger, T., Lepukhov, B., Belyaev, G., and Borrmann, S.: Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application, Atmos. Meas. Tech., 2, 243–258, 2009. Yushkov, V., Oulanovsky, A., Lechenuk, N., Roudakov, I., Arshinov, K., Tikhonov, F., Stefanutti, L., Ravegnani, F., Bonafe, U., and Georgiadis, T.: A chemiluminescent analyzer for stratospheric measurements of the ozone concentration (FOZAN), J. Atmos. Ocean. Tech., 16, 1345–1350, 1999. Zöger, M., Afchine, A., Eicke, N., Gerhards, M. T., Klein, E., McKenna, D. S., Mörschel, U., Schmidt, U., Tan, V., Tuitjer, F., Woyke, T., and Schiller, C.: Fast in-situ stratospheric hygrometers: A new family of balloonborne and airborne Lyman-α photofragment fluorescence hygrometers, J. Geophys. Res., 104, 1807–1816, 1999.