Ice formation by black carbon particles

Ice formation by black carbon particles was studied using a continuous flow thermal diffusion chamber. Submicron particles were treated to uptake H2SO4 in amounts estimated to range from zero to several percent by weight. The particles were processed at constant temperatures (−40 to −60°C), and humidity from ice saturation to values exceeding water saturation. Conditions required for ice nucleation were determined for different acid exposures. Untreated soot particles showed activity as deposition/sorption ice nuclei. Particles with approximate monolayer equivalent coverage by H2SO4 nucleated ice at humidities for which it was inferred that the acid was dilute enough to freeze homogeneously on soot surfaces. Particles with multi‐layer equivalent H2SO4 coverage froze as solution droplets most readily. Heterogeneous freezing of the latter particles was observed to occur in preference to the homogeneous freezing of an externally mixed population of H2SO4 droplets at lower temperatures.

[1]  K. Diehl,et al.  A laboratory study of the effects of a kerosene-burner exhaust on ice nucleation and the evaporation rate of ice crystals , 1998 .

[2]  N. A. Kakutkina,et al.  Ice nucleation on soot particles , 1998 .

[3]  K. Sassen,et al.  Toward the theory of homogeneous nucleation and its parameterization for cloud models , 1998 .

[4]  A. Petzold,et al.  Elemental composition and morphology of ice-crystal residual particles in cirrus clouds and contrails , 1998 .

[5]  B. Kärcher.  Physicochemistry of aircraft‐generated liquid aerosols, soot, and ice particles: 1. Model description , 1998 .

[6]  S. Kreidenweis,et al.  Single particle analyses of ice nucleating aerosols in the upper troposphere and lower stratosphere , 1998 .

[7]  S. Kreidenweis,et al.  Measurements of ice nucleating aerosols during SUCCESS , 1998 .

[8]  Bruce E. Anderson,et al.  Ice nucleation processes in upper tropospheric wave‐clouds observed during SUCCESS , 1998 .

[9]  Cynthia H. Twohy,et al.  Electron microscope analysis of residual particles from aircraft contrails , 1998 .

[10]  S. Kreidenweis,et al.  The role of heterogeneous freezing nucleation in upper tropospheric clouds: Inferences from SUCCESS , 1998 .

[11]  J. Ström,et al.  Real-time measurement of absorbing material in contrail ice using a counterflow virtual impactor , 1998 .

[12]  Richard C. Miake-Lye,et al.  Environmental conditions required for contrail formation and persistence , 1998 .

[13]  Peter Brimblecombe,et al.  Thermodynamic Model of the System H+−NH4+−SO42-−NO3-−H2O at Tropospheric Temperatures , 1998 .

[14]  Richard P. Turco,et al.  Contrail formation and impacts on aerosol properties in aircraft plumes: Effects of fuel sulfur content , 1998 .

[15]  D. Murphy,et al.  On the Purity of Laboratory-Generated Sulfuric Acid Droplets and Ambient Particles Studied by Laser Mass Spectrometry , 1997 .

[16]  S. Kreidenweis,et al.  The susceptibility of ice formation in upper tropospheric clouds to insoluble aerosol components , 1997 .

[17]  M. Baker,et al.  Cloud Microphysics and Climate , 1997 .

[18]  G. C. Tiao,et al.  Analysis of long-term behavior of ultraviolet radiation measured by Robertson-Berger meters at 14 sites in the United States , 1997 .

[19]  D. Golden,et al.  Reactive uptake and hydration experiments on amorphous carbon treated with NO2, SO2, O3, HNO3, and H2SO4 , 1997 .

[20]  The potential impact of soot particles from aircraft exhaust on cirrus clouds , 1997 .

[21]  U. Schumann,et al.  The Initial Composition of Jet Condensation Trails , 1996 .

[22]  P. Sheridan,et al.  Aerosol particles in the upper troposphere and lower stratosphere: Elemental composition and morphology of individual particles in northern midlatitudes , 1994 .

[23]  W. T. Rawlins,et al.  Observation of hydration of single, modified carbon aerosols , 1994 .

[24]  P. Machetel,et al.  Convection within the inner‐core and thermal implications , 1992 .

[25]  K. Snetsinger,et al.  Black carbon (soot) aerosol in the lower stratosphere and upper troposphere , 1992 .

[26]  Philip D. Whitefield,et al.  A field sampling of jet exhaust aerosols , 1992 .

[27]  P. DeMott.  An Exploratory Study of Ice Nucleation by Soot Aerosols , 1990 .

[28]  D. Rogers.  Development of a continuous flow thermal gradient diffusion chamber for ice nucleation studies , 1988 .