The dependence of ice microphysics on aerosol concentration in arctic mixed‐phase stratus clouds during ISDAC and M‐PACE

[1] Cloud and aerosol data acquired by the National Research Council of Canada (NRC) Convair-580 aircraft in, above, and below single-layer arctic stratocumulus cloud during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 were used to test three aerosol indirect effects hypothesized to act in mixed-phase clouds: the riming indirect effect, the glaciation indirect effect, and the thermodynamic indirect effect. The data showed a correlation of R = 0.78 between liquid drop number concentration, Nliq inside cloud and ambient aerosol number concentration NPCASP below cloud. This, combined with increasing liquid water content LWC with height above cloud base and the nearly constant vertical profile of Nliq, suggested that liquid drops nucleated from aerosol at cloud base. No evidence of a riming indirect effect was observed, but a strong correlation of R = 0.69 between ice crystal number concentration Ni and NPCASP above cloud was noted. Increases in ice nuclei (IN) concentration with NPCASP above cloud for 2 flight dates combined with the subadiabatic LWC profiles suggest possible mixing of IN from cloud top consistent with the glaciation indirect effect. The lower Nice and lower effective radius rel for the more polluted ISDAC cases compared to data collected in cleaner single-layer stratocumulus conditions during the Mixed-Phase Arctic Cloud Experiment is consistent with the operation of the thermodynamic indirect effect. However, more data in a wider variety of meteorological and surface conditions, with greater variations in aerosol forcing, are required to identify the dominant aerosol forcing mechanisms in mixed-phase arctic clouds.

[1]  Sergey Y. Matrosov,et al.  Arctic Cloud Microphysics Retrievals from Surface-Based Remote Sensors at SHEBA , 2005 .

[2]  H. B. Mann,et al.  On a Test of Whether one of Two Random Variables is Stochastically Larger than the Other , 1947 .

[3]  Ann M. Fridlind,et al.  Ice properties of single‐layer stratocumulus during the Mixed‐Phase Arctic Cloud Experiment: 1. Observations , 2007 .

[4]  P. Field,et al.  The effect of dynamics on mixed-phase clouds: Theoretical considerations , 2008 .

[5]  S. Schneider,et al.  Climate Change 2007 Synthesis report , 2008 .

[6]  U. Lohmann,et al.  The cloud albedo-cloud droplet effective radius relationship for clean and polluted clouds from RACE and FIRE.ACE , 2002 .

[7]  J. Hallett,et al.  Production of secondary ice particles during the riming process , 1974, Nature.

[8]  J. Harrington,et al.  On the potential influence of ice nuclei on surface‐forced marine stratocumulus cloud dynamics , 2001 .

[9]  J. Curry,et al.  Sensitivity of modeled arctic mixed‐phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions , 2008 .

[10]  J. Curry,et al.  Cloud-aerosol interactions during autumn over Beaufort Sea , 2001 .

[11]  J. Curry,et al.  Surface Heat Budget of the Arctic Ocean , 2002 .

[12]  S. Kreidenweis,et al.  A Continuous-Flow Diffusion Chamber for Airborne Measurements of Ice Nuclei , 2001 .

[13]  Peter V. Hobbs,et al.  Ice particles in stratiform clouds in the Arctic and possible mechanisms for the production of high ice concentrations , 2001 .

[14]  A. Korolev,et al.  The Nevzorov Airborne Hot-Wire LWC-TWC Probe: Principle of Operation and Performance Characteristics , 1998 .

[15]  P. Field,et al.  Shattering and Particle Interarrival Times Measured by Optical Array Probes in Ice Clouds , 2006 .

[16]  D. Mitchell.  Use of Mass- and Area-Dimensional Power Laws for Determining Precipitation Particle Terminal Velocities , 1996 .

[17]  M. Shupe,et al.  Moisture and dynamical interactions maintaining decoupled Arctic mixed-phase stratocumulus in the presence of a humidity inversion , 2011 .

[18]  Andrew J. Heymsfield,et al.  Parameterization of Tropical Cirrus Ice Crystal Size Distributions and Implications for Radiative Transfer: Results from CEPEX , 1997 .

[19]  R. Lawson.  Effects of ice particles shattering on the 2D-S probe , 2011 .

[20]  P. Pilewskie,et al.  Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project , 2010 .

[21]  W. Cotton,et al.  Chapter 10 - The Mesoscale Structure of Extratropical Cyclones and Middle and High Clouds , 2011 .

[22]  D. Lowenthal,et al.  Mountaintop and radar measurements of anthropogenic aerosol effects on snow growth and snowfall rate , 2003 .

[23]  Judith A. Curry,et al.  Impact of clouds on the surface radiation balance of the Arctic Ocean , 1993 .

[24]  S. Twomey.  Pollution and the Planetary Albedo , 1974 .

[25]  Patrick Minnis,et al.  The Mixed-Phase Arctic Cloud Experiment. , 2007 .

[26]  A. Stohl,et al.  Cloud condensation nuclei as a modulator of ice processes in Arctic mixed-phase clouds , 2011 .

[27]  David S. Covert,et al.  Design and Calibration of a Counterflow Virtual Impactor for Sampling of Atmospheric Fog and Cloud Droplets , 1988 .

[28]  C. Twohy,et al.  Measurement of Condensed Water Content in Liquid and Ice Clouds Using an Airborne Counterflow Virtual Impactor , 1997 .

[29]  Edgar L. Andreas,et al.  An annual cycle of Arctic surface cloud forcing at SHEBA : The surface heat budget of arctic ocen (SHEBA) , 2002 .

[30]  A. Korolev,et al.  Assessing Cloud-Phase Conditions , 2001 .

[31]  Glenn E. Shaw,et al.  A 3‐year record of simultaneously measured aerosol chemical and optical properties at Barrow, Alaska , 2002 .

[32]  S. Tsay,et al.  Physical characteristics of arctic stratus clouds , 1984 .

[33]  Greg Michael McFarquhar,et al.  Light Scattering by Quasi-Spherical Ice Crystals , 2004 .

[34]  John Hallett,et al.  Degradation of In-Cloud Forward Scattering Spectrometer Probe Measurements in the Presence of Ice Particles , 1985 .

[35]  Patrick Minnis,et al.  Arctic Stratus Cloud Properties and Their Effect on the Surface Radiation Budget: Selected Cases from FIRE ACE , 2001 .

[36]  I. Gultepe,et al.  Ice crystal number concentration versus temperature for climate studies , 2001 .

[37]  U. Lohmann,et al.  A glaciation indirect aerosol effect caused by soot aerosols , 2002 .

[38]  Alexei Korolev,et al.  NOTES AND CORRESPONDENCE Airspeed Corrections for Optical Array Probe Sample Volumes , 1997 .

[39]  Glenn E. Shaw,et al.  Atmospheric Turbidity in the Polar Regions. , 1982 .

[40]  Mengistu Wolde,et al.  Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds , 2011 .

[41]  G. McFarquhar,et al.  Single-Scattering Properties of Mixed-Phase Arctic Clouds at Solar Wavelengths: Impacts on Radiative Transfer , 2004 .

[42]  Brad Baker,et al.  An overview of microphysical properties of Arctic clouds observed in May and July 1998 during FIRE ACE , 2001 .

[43]  Alexei Korolev,et al.  Reconstruction of the Sizes of Spherical Particles from Their Shadow Images. Part I: Theoretical Considerations , 2007 .

[44]  J. Walter Strapp,et al.  Laboratory Measurements of the Response of a PMS OAP-2DC , 2001 .

[45]  A. Korolev,et al.  Small Ice Particles in Tropospheric Clouds: Fact or Artifact? Airborne Icing Instrumentation Evaluation Experiment , 2011 .

[46]  U. Lohmann,et al.  Global indirect aerosol effects: a review , 2004 .

[47]  D. Lubin,et al.  A climatologically significant aerosol longwave indirect effect in the Arctic , 2006, Nature.

[48]  K. B. Strawbridge,et al.  Turbulent heat fluxes over leads and polynyas, and their effects on arctic clouds during FIRE.ACE: Aircraft observations for April 1998 , 2003 .

[49]  Taneil Uttal,et al.  Airborne studies of cloud structures over the Arctic Ocean and comparisons with retrievals from ship-based remote sensing measurements , 2001 .

[50]  R. Lawson,et al.  The 2D-S (Stereo) Probe: Design and Preliminary Tests of a New Airborne, High-Speed, High-Resolution Particle Imaging Probe , 2006 .

[51]  Joshua P. Schwarz,et al.  Biomass burning in Siberia and Kazakhstan as an important source for haze over the Alaskan Arctic in April 2008 , 2009 .

[52]  G. Mace,et al.  Effects of varying aerosol regimes on low‐level Arctic stratus , 2004 .

[53]  G. McFarquhar,et al.  Dependence of the single-scattering properties of small ice crystals on idealized shape models , 2010 .

[54]  Robert Wood,et al.  Ice Particle Interarrival Times Measured with a Fast FSSP , 2003 .

[55]  Brad Baker,et al.  Improvement in Determination of Ice Water Content from Two-Dimensional Particle Imagery. Part I: Image-to-Mass Relationships , 2006 .

[56]  Chuanfeng Zhao,et al.  Increased Arctic cloud longwave emissivity associated with pollution from mid-latitudes , 2006, Nature.

[57]  J. Hansen,et al.  Light scattering in planetary atmospheres , 1974 .

[58]  R. Kerr.  Pollution of the arctic atmosphere confirmed. , 1981, Science.

[59]  Greg Michael McFarquhar,et al.  Microphysical Characteristics of Three Anvils Sampled during the Central Equatorial Pacific Experiment , 1996 .

[60]  J. Curry.  Interactions among aerosols, clouds, and climate of the Arctic Ocean , 1995 .

[61]  Andrew J. Heymsfield,et al.  A Computational Technique for Increasing the Effective Sampling Volume of the PMS Two-Dimensional Particle Size Spectrometer , 1978 .

[62]  Timothy J. Garrett,et al.  Aerosol Effects on Cloud Emissivity and Surface Longwave Heating in the Arctic , 2002 .

[63]  P. Francis,et al.  Improved Measurements of the Ice Water Content in Cirrus Using a Total-Water Probe , 1995 .

[64]  D. Baumgardner,et al.  Icing Wind Tunnel Tests on the CSIRO Liquid Water Probe , 1985 .

[65]  G. McFarquhar,et al.  Single‐scattering properties of aggregates of plates , 2009 .

[66]  Guy Febvre,et al.  The Reliability of the PMS FSSP in the Presence of Small Ice Crystals , 1996 .

[67]  M. Shupe,et al.  Cloud water contents and hydrometeor sizes during the FIRE Arctic Clouds Experiment , 2001 .

[68]  M. Shupe,et al.  An annual cycle of Arctic cloud characteristics observed by radar and lidar at SHEBA , 2002 .

[69]  B. Albrecht.  Aerosols, Cloud Microphysics, and Fractional Cloudiness , 1989, Science.

[70]  M. Shupe,et al.  On the Relationship between Thermodynamic Structure and Cloud Top, and Its Climate Significance in the Arctic , 2012 .

[71]  P. Hobbs,et al.  Ice particle concentrations and precipitation development in small polar maritime cumuliform clouds , 1991 .

[72]  J. Curry,et al.  FIRE Arctic Clouds Experiment , 2013 .

[73]  G. McFarquhar,et al.  Factors influencing the microphysics and radiative properties of liquid-dominated Arctic clouds: insight from observations of aerosol and clouds during ISDAC , 2011 .

[74]  L. Barrie,et al.  Arctic air pollution: An overview of current knowledge , 1986 .

[75]  P. Hobbs,et al.  Microstructures of low and middle‐level clouds over the Beaufort Sea , 1998 .

[76]  G. McFarquhar,et al.  Vertical Motions in Arctic Mixed-Phase Stratiform Clouds , 2008 .