References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-11-257-2011

Observations of ice multiplication in a weakly convective cell embedded in supercooled mid-level stratus

Crosier

¹ ² Bower

K. N.

¹ Choularton

T. W.

¹ Westbrook

C. D.

³ Connolly

P. J.

¹ Cui

Z. Q.

⁴ Crawford

I. P.

¹ Capes

G. L.

¹ Coe

¹ Dorsey

J. R.

¹ ² Williams

P. I.

¹ ² Illingworth

A. J.

³ Gallagher

M. W.

¹ Blyth

A. M.

² ⁴

Centre for Atmospheric Science, SEAES, University of Manchester, Manchester, UK

National Centre for Atmospheric Science, University of Manchester, Manchester, UK

Department of Meteorology, University of Reading, Reading, UK

School of Earth and Environment, University of Leeds, Leeds, UK

13 01 2011

11 1 257 273

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Simultaneous observations of cloud microphysical properties were obtained by in-situ aircraft measurements and ground based Radar/Lidar. Widespread mid-level stratus cloud was present below a temperature inversion (~5 °C magnitude) at 3.6 km altitude. Localised convection (peak updraft 1.5 m s−1) was observed 20 km west of the Radar station. This was associated with convergence at 2.5 km altitude. The convection was unable to penetrate the inversion capping the mid-level stratus. The mid-level stratus cloud was vertically thin (~400 m), horizontally extensive (covering 100 s of km) and persisted for more than 24 h. The cloud consisted of supercooled water droplets and small concentrations of large (~1 mm) stellar/plate like ice which slowly precipitated out. This ice was nucleated at temperatures greater than −12.2 °C and less than −10.0 °C, (cloud top and cloud base temperatures, respectively). No ice seeding from above the cloud layer was observed. This ice was formed by primary nucleation, either through the entrainment of efficient ice nuclei from above/below cloud, or by the slow stochastic activation of immersion freezing ice nuclei contained within the supercooled drops. Above cloud top significant concentrations of sub-micron aerosol were observed and consisted of a mixture of sulphate and carbonaceous material, a potential source of ice nuclei. Particle number concentrations (in the size range 0.1<D<3.0 μm) were measured above and below cloud in concentrations of ~25 cm−3. Ice crystal concentrations in the cloud were constant at around 0.2 L−1. It is estimated that entrainment of aerosol particles into cloud cannot replenish the loss of ice nuclei from the cloud layer via precipitation. Precipitation from the mid-level stratus evaporated before reaching the surface, whereas rates of up to 1 mm h−1 were observed below the convective feature. There is strong evidence for the Hallett-Mossop (HM) process of secondary ice particle production leading to the formation of the precipitation observed. This includes (1) Ice concentrations in the convective feature were more than an order of magnitude greater than the concentration of primary ice in the overlaying stratus, (2) Large concentrations of small pristine columns were observed at the ~−5 °C level together with liquid water droplets and a few rimed ice particles, (3) Columns were larger and increasingly rimed at colder temperatures. Calculated ice splinter production rates are consistent with observed concentrations if the condition that only droplets greater than 24 μm are capable of generating secondary ice splinters is relaxed. This case demonstrates the importance of understanding the formation of ice at slightly supercooled temperatures, as it can lead to secondary ice production and the formation of precipitation in clouds which may not otherwise be considered as significant precipitation sources.

References 1

Baumgardner,~D., Jonsson,~H., Dawson,~W., O'Connor,~D., and Newton,~R.: The cloud, aerosol and precipitation spectrometer: a new instrument for cloud investigations, Atmos. Res., 59–60, 251–264, 2001.

Beard,~K V. and Grover,~S N.: Numerical collision efficiencies for small raindrops colliding with micron size particles, J. Atmos. Sci., 31, 543–550, 1974.

Blyth,~A M. and Latham,~J.: A multi-thermal model of cumulus glaciation via the Hallett-Mossop process, Q. J. Roy. Meteorol. Soc., 123, 1185–1198, 1997.

Bretherton,~C S., Uttal,~T., Fairall,~C W., Yuter,~S E., Weller,~R A., Baumgardner,~D., Comstock,~K., Wood,~R., and Raga,~G B.: The EPIC 2001 stratocumulus study, B. Am. Meteorol. Soc., 85, 967–977, 2004.

Brown,~P R A. and Francis,~P N.: Improved measurements of the ice water-content in cirrus using a total-water probe, J. Atmos. Ocean. Tech., 12, 410–414, 1995.

Canagaratna,~M R., Jayne,~J T., Jimenez,~J L., Allan,~J D., Alfarra,~M R., Zhang,~Q., Onasch,~T B., Drewnick,~F., Coe,~H., Middlebrook,~A., Delia,~A., Williams,~L R., Trimborn,~A M., Northway,~M J., DeCarlo,~P F., Kolb,~C E., Davidovits,~P., and Worsnop,~D R.: Chemical and microphysical characterization of ambient aerosols with the aerodyne aerosol mass spectrometer, Mass Spectrom. Rev., 26, 185–222, 2007.

Choularton,~T W., Bower,~K N., Weingartner,~E., Crawford,~I., Coe,~H., Gallagher,~M W., Flynn,~M., Crosier,~J., Connolly,~P., Targino,~A., Alfarra,~M R., Baltensperger,~U., Sjogren,~S., Verheggen,~B., Cozic,~J., and Gysel,~M.: The influence of small aerosol particles on the properties of water and ice clouds, Faraday Discuss., 137, 205–222, 2008.

Clark,~P D., Choularton,~T W., Brown,~P R A., Field,~P R., Illingworth,~A J., and Hogan,~R J.: Numerical modelling of mixed-phase frontal clouds observed during the CWVC project, Q. J. Roy. Meteor. Soc., 131, 1677–1693, 2005.

Connolly, P. J., Möhler, O., Field, P. R., Saathoff, H., Burgess, R., Choularton, T., and Gallagher, M.: Studies of heterogeneous freezing by three different desert dust samples, Atmos. Chem. Phys., 9, 2805–2824, doi:10.5194/acp-9-2805-2009, 2009.

Crosier,~J., Allan,~J D., Coe,~H., Bower,~K N., Formenti,~P., and Williams,~P I.: Chemical composition of summertime aerosol in the Po Valley (Italy), Northern Adriatic and Black Sea, Q. J. Roy. Meteor. Soc., 133, 61–75, 2007.

DeMott,~P J. and Prenni,~A J.: New Directions: Need for defining the numbers and sources of biological aerosols acting as ice nuclei, Atmos. Environ., 44, 1944–1945, 2010.

DeMott,~P J., Prenni,~A J., Liu,~X., Kreidenweis,~S M., Petters,~M D., Twohy,~C H., Richardson,~M S., Eidhammer,~T., and Rogers,~D C.: Predicting global atmospheric ice nuclei distributions and their impacts on climate, Proc. Natl. Acad. Sci., 107(25), 11217–11222, doi:10.1073/pnas.0910818107, 2010.

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.

Goddard,~J W F., Eastment,~J D., and Thurai,~M.: The Chilbolton advanced meteorological radar – a tool for multidisciplinary atmospheric research, Electron. Comm. Eng., 6, 77–86, 1994.

Hallett,~J. and Mossop,~S C.: Production of secondary ice particles during riming process, Nature, 249, 26–28, 1974.

Harris-Hobbs,~R L. and Cooper,~W A.: Field evidence supporting quantitative predictions of secondary ice production-rates, J. Atmos. Sci., 44, 1071–1082, 1987.

Heymsfield,~A J., Bansemer,~A., Field,~P R., Durden,~S L., Stith,~J L., Dye,~J E., Hall,~W., and Grainger,~C A.: Observations and parameterizations of particle size distributions in deep tropical cirrus and stratiform precipitating clouds: results from in situ observations in TRMM field campaigns, J. Atmos. Sci., 59, 3457–3491, 2002.

Hogan,~R J., Field,~P R., Illingworth,~A J., Cotton,~R J., and Choularton,~T W.: Properties of embedded convection in warm-frontal mixed-phase cloud from aircraft and polarimetric radar, Q. J. Roy. Meteor. Soc., 128, 451–476, 2002.

Hogan,~R J., Francis,~P N., Flentje,~H., Illingworth,~A J., Quante,~M., and Pelon,~J.: Characteristics of mixed-phase clouds. I: Lidar, radar and aircraft observations from CLARE'98, Q. J. Roy. Meteor. Soc., 129, 2089–2116, 2003a.

Hogan,~R J., Illingworth,~A J., O'Connor,~E J., and Baptista,~J P V P.: Characteristics of mixed-phase clouds. II: A climatology from ground-based lidar, Q. J. Roy. Meteorol. Soc., 129, 2117–2134, 2003b.

Hogan,~R J., Behera,~M D., O'Connor,~E J., and Illingworth,~A J.: Estimate of the global distribution of stratiform supercooled liquid water clouds using the LITE lidar, Geophys. Res. Lett., 31, L05106, 2004.

Huang,~Y H., Blyth,~A M., Brown,~P R A., Choularton,~T W., Connolly,~P., Gadian,~A M., Jones,~H., Latham,~J., Cui,~Z Q., and Carslaw,~K.: The development of ice in a cumulus cloud over Southwest England, New J. Phys., 10, 10521, 2008.

Illingworth,~A J., Hogan,~R J., O'Connor,~E J., Bouniol,~D., Brooks,~M E., Delanoe,~J., Donovan,~D P., Eastment,~J D., Gaussiat,~N., Goddard,~J W F., Haeffelin,~M., Baltink,~H K., Krasnov,~O A., Pelon,~J., Piriou,~J M., Protat,~A., Russchenberg,~H W J., Seifert,~A., Tompkins,~A M., van Zadelhoff,~G J., Vinit,~F., Willen,~U., Wilson,~D R., and Wrench,~C L.: Cloudnet – continuous evaluation of cloud profiles in seven operational models using ground-based observations, B. Am. Meteorol. Soc., 88, 883–898, 2007.

Klein,~S A., McCoy,~R B., Morrison,~H., Ackerman,~A S., Avramov,~A., de~Boer,~G., Chen,~M X., Cole,~J N S., Del~Genio,~A D., Falk,~M., Foster,~M J., Fridlind,~A., Golaz,~J C., Hashino,~T., Harrington,~J Y., Hoose,~C., Khairoutdinov,~M F., Larson,~V E., Liu,~X H., Luo,~Y L., McFarquhar,~G M., Menon,~S., Neggers,~R A J., Park,~S., Poellot,~M R., Schmidt,~J M., Sednev,~I., Shipway,~B J., Shupe,~M D., Spangenbery,~D A., Sud,~Y C., Turner,~D D., Veron,~D E., von Salzen,~K., Walker,~G K., Wang,~Z E., Wolf,~A B., Xie,~S C., Xu,~K M., Yang,~F L., and Zhang,~G.: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. I: Single-layer cloud, Q. J. Roy. Meteorol. Soc., 135, 979–1002, 2009.

Knollenberg, R. G.: Techniques for probing cloud microstructure, in: Clouds, Their Formation, Optical Properties, and Effects, edited by: Hobbs, P. V. and Deepak, A., Academic Press, New York, USA, 15–91, 1981.

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.

Lawson,~R P., O'Connor,~D., Zmarzly,~P., Weaver,~K., Baker,~B., Mo,~Q X., and Jonsson,~H.: The 2D-S (Stereo) probe: design and preliminary tests of a new airborne, high-speed, high-resolution particle imaging probe, J. Atmos. Ocean. Tech., 23, 1462–1477, 2006.

Marshall,~J S. and Palmer,~W M.: The distribution of raindrops with size, J. Meteorol., 5, 165–166, 1948.

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.

Meyers,~M P., Demott,~P J., and Cotton,~W R.: New primary ice-nucleation parameterizations in an explicit cloud model, J. Appl. Meteorol., 31, 708–721, 1992.

Mitchell,~D L.: Use of mass- and area-dimensional power laws for determining precipitation particle terminal velocities, J. Atmos. Sci., 53, 1710–1723, 1996.

Moeng,~C H., Sullivan,~P P., and Stevens,~B.: Including radiative effects in an entrainment rate formula for buoyancy-driven PBLs, J. Atmos. Sci., 56, 1031–1049, 1999.

Möhler, O., Field, P. R., Connolly, P., Benz, S., Saathoff, H., Schnaiter, M., Wagner, R., Cotton, R., Krämer, M., Mangold, A., and Heymsfield, A. J.: Efficiency of the deposition mode ice nucleation on mineral dust particles, Atmos. Chem. Phys., 6, 3007–3021, doi:10.5194/acp-6-3007-2006, 2006.

Mossop,~S C. and Hallett,~J.: Ice crystal concentration in cumulus clouds – influence of drop spectrum, Science, 186, 632–634, 1974.

Murray,~B J., Wilson,~T W., Dobbie,~S., Cui,~Z., Al-Jumur,~S M R K., Mohler,~O., Schnaiter,~M., Wagner,~R., Benz,~S., Niemand,~M., Saathoff,~H., Ebert,~V., Wagner,~S. and Karcher,~B.: Heterogeneous nucleation of ice particles on glassy aerosols under cirrus conditions, Nat. Geosci., 4, 233–237, 2010.

Pruppacher,~H R. and Klett,~J D.: Microphysics of Clouds and Precipitation, Kluwer Acad., Norwell, MA, USA, 18, 42–44, 1997.

Ramanathan,~V., Cess,~R D., Harrison,~E F., Minnis,~P., Barkstrom,~B R., Ahmad,~E., and Hartmann,~D.: Cloud-radiative forcing and climate – results from the Earth Radiation Budget Experiment, Science, 243, 57–63, 1989.

Rangno,~A L. and Hobbs,~P V.: Ice particles in stratiform clouds in the Arctic and possible mechanisms for the production of high ice concentrations, J. Geophys. Res.-Atmos., 106, 15065–15075, 2001.

Ryan,~B F., Wishart,~E R., and Shaw,~D E.: Growth-rates and densities of ice crystals between −3 \degree C and −21 \degree C, J. Atmos. Sci., 33, 842–850, 1976.

Targino,~A C., Coe,~H., Cozic,~J., Crosier,~J., Crawford,~I., Bower,~K., Flynn,~M., Gallagher,~M., Allan,~J., Verheggen,~B., Weingartner,~E., Baltensperger,~U., and Choularton,~T.: Influence of particle chemical composition on the phase of cold clouds at a high-alpine site in Switzerland, J. Geophys. Res.-Atmos., 114, D18206, doi:10.1029/2008JD011365, 2009.

Verlinde,~J., Harrington,~J Y., McFarquhar,~G M., Yannuzzi,~V T., Avramov,~A., Greenberg,~S., Johnson,~N., Zhang,~G., Poellot,~M R., Mather,~J H., Turner,~D D., Eloranta,~E W., Zak,~B D., Prenni,~A J., Daniel,~J S., Kok,~G L., Tobin,~D C., Holz,~R., Sassen,~K., Spangenberg,~D., Minnis,~P., Tooman,~T P., Ivey,~M D., Richardson,~S J., Bahrmann,~C P., Shupe,~M., DeMott,~P J., Heymsfield,~A J., and Schofield,~R.: The mixed-phase Arctic cloud experiment, B. Am. Meteorol. Soc., 88, 205–221, 2007.

Virtanen, A., Joutsensaari, J., Koop, T., Kannosto, J., Yli-Pirila, P., Leskinen, J., Makela, J. M., Holopainen, J. K., Poschl, U., Kulmala, M., Worsnop, D. R. and Laaksonen, A.: An amorphous solid state of biogenic secondary organic aerosol particles, Nature, 467, 824–827, 2010.