Accumulation mode aerosol, pockets of open cells, and particle nucleation in the remote subtropical Pacific marine boundary layer

[1] We analyze a marine boundary layer cloud field encountered during the second research flight of the second Dynamics and Chemistry of Marine Stratocumulus Experiment. The cloud field is distinguished by the presence of pockets of open cells. Differences between the pockets and the surrounding stratocumulus clouds are studied utilizing in situ and satellite data. The pockets are characterized as regions where cloud radar echo tops are unusually variable, accumulation mode aerosol concentrations are low, and Aitken mode particles with a mode diameter at 0.02 μm dominate aerosol number concentration. The Aitken mode particles are thought to be generated by a nucleation event which occurred within the marine boundary layer. The low accumulation mode concentrations associated with the pockets are proposed to be necessary for their maintenance.

[1]  Bjorn Stevens,et al.  Observations of the Structure of Heavily Precipitating Marine Stratocumulus. , 2005 .

[2]  B. Stevens,et al.  Observations of Entrainment in Eastern Pacific Marine Stratocumulus Using Three Conserved Scalars , 2005 .

[3]  Melanie A. Wetzel,et al.  Evaluation of the aerosol indirect effect in marine stratocumulus clouds : droplet number, size, liquid water path, and radiative impact , 2005 .

[4]  B. Stevens,et al.  Observations of Drizzle in Nocturnal Marine Stratocumulus , 2005 .

[5]  C. Bretherton,et al.  POCKETS OF OPEN CELLS AND DRIZZLE IN MARINE STRATOCUMULUS , 2004 .

[6]  J. Putaud,et al.  Aerosol activation in marine stratocumulus clouds: 2. Köhler and parcel theory closure studies , 2003 .

[7]  Hanna Pawlowska,et al.  An observational study of drizzle formation in stratocumulus clouds for general circulation model (GCM) parameterizations , 2003 .

[8]  J. Brenguier,et al.  Aerosol activation in marine stratocumulus clouds: 1. Measurement validation for a closure study , 2003 .

[9]  D. Lilly,et al.  Supplement to Dynamics and Chemistry of Marine Stratocumulus—DYCOMS-II , 2003 .

[10]  D. Lilly,et al.  Dynamics and chemistry of marine stratocumulus - DYCOMS II , 2003 .

[11]  M. Noguer,et al.  Climate change 2001: The scientific basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change , 2002 .

[12]  J. Seinfeld,et al.  Marine aerosol formation from biogenic iodine emissions , 2002, Nature.

[13]  K. Hämeri,et al.  Hygroscopic properties of aerosol particles over the central Arctic Ocean during summer , 2001 .

[14]  Ü. Rannik,et al.  Turbulent aerosol fluxes over the Arctic Ocean: 2. Wind‐driven sources from the sea , 2001 .

[15]  L. S. Hughes,et al.  Closure between aerosol particles and cloud condensation nuclei at Kaashidhoo Climate Observatory , 2001 .

[16]  B. J. Mason.  The role of sea-salt particles as cloud condensation nuclei over the remote oceans , 2001 .

[17]  Ü. Rannik,et al.  Turbulent aerosol fluxes over the Arctic Ocean , 2001 .

[18]  Liisa Pirjola,et al.  Can new particle formation occur in the clean marine boundary layer , 2000 .

[19]  J. Brenguier,et al.  Microphysical properties of stratocumulus clouds during ACE‐2 , 2000 .

[20]  J. Brenguier,et al.  Cloud condensation nuclei and cloud droplet measurements during ACE-2 , 2000 .

[21]  J. Seinfeld,et al.  CCN measurements during ACE-2 and their relationship to cloud microphysical properties , 2000 .

[22]  D. Hegg.  Dependence of marine stratocumulus formation on aerosols , 1999 .

[23]  B. Stevens,et al.  Large-Eddy Simulations of Strongly Precipitating, Shallow, Stratocumulus-Topped Boundary Layers , 1998 .

[24]  G. Vali,et al.  Finescale Structure and Microphysics of Coastal Stratus , 1998 .

[25]  P. Mcmurry,et al.  Spurious aerosol measurements when sampling from aircraft in the vicinity of clouds , 1998 .

[26]  Bandy,et al.  Particle nucleation in the tropical boundary layer and its coupling to marine sulfur sources , 1998, Science.

[27]  Sonia M. Kreidenweis,et al.  A study of new particle formation and growth involving biogenic and trace gas species measured during ACE 1 , 1998 .

[28]  D. Lenschow,et al.  Bidirectional mixing in an ACE 1 marine boundary layer overlain by a second turbulent layer , 1998 .

[29]  D. Covert,et al.  Comparison of directly measured CCN with CCN modeled from the number-size distribution in the marine boundary layer during ACE 1 at Cape Grim, Tasmania , 1998 .

[30]  J. Hudson,et al.  Comparisons of cloud microphysics with cloud condensation nuclei spectra over the summertime Southern Ocean , 1998 .

[31]  Antony D. Clarke,et al.  Particle production in the remote marine atmosphere: Cloud outflow and subsidence during ACE 1 , 1998 .

[32]  P. V. Velthoven,et al.  Observations of aerosols in the free troposphere and marine boundary layer of the subtropical Northeast Atlantic: Discussion of processes determining their size distribution , 1997 .

[33]  C. N. Hewitt,et al.  Biogenic sulphur emissions and inferred non‐sea‐salt‐sulphate cloud condensation nuclei in and around Antarctica , 1997 .

[34]  J. Seinfeld,et al.  Radially Classified Aerosol Detector for Aircraft-Based Submicron Aerosol Measurements , 1996 .

[35]  P. Quinn,et al.  Physical properties of marine boundary layer aerosol particles of the mid-Pacific in relation to sources and meteorological transport , 1996 .

[36]  J. W. Fitzgerald,et al.  Marine boundary layer measurements of new particle formation and the effects nonprecipitating clouds have on aerosol size distribution , 1994 .

[37]  Robert E. McIntosh,et al.  An airborne 95 GHz dual-polarized radar for cloud studies , 1994, IEEE Trans. Geosci. Remote. Sens..

[38]  H. Gerber,et al.  New microphysics sensor for aircraft use , 1994 .

[39]  P. Hobbs,et al.  Dissipation of Marine Stratiform Clouds and Collapse of the Marine Boundary Layer Due to the Depletion of Cloud Condensation Nuclei by Clouds , 1993, Science.

[40]  M. H. Smith,et al.  Physicochemical properties of aerosols over the northeast Atlantic: Evidence for wind‐speed‐related submicron sea‐salt aerosol production , 1993 .

[41]  N. Brown,et al.  Measurement Uncertainties of the NCAR Air Motion Systems , 1993 .

[42]  P. Quinn,et al.  New particle formation in the marine boundary layer , 1992 .

[43]  D. Lenschow,et al.  Comment on "Measurements of Aitken nuclei and cloud condensation nuclei in the marine atmosphere and their relation to the DMS-cloud-climate hypothesis" by D. A. Hegg, L. F. Radke, and P. V. Hobbs , 1992 .

[44]  L. Radke,et al.  Measurements of Aitken nuclei and cloud condensation nuclei in the marine atmosphere and their relation to the DMS‐Cloud‐climate hypothesis , 1991 .

[45]  Harshvardhan,et al.  Diurnal Variability of the Hydrologic Cycle in a General Circulation Model , 1991 .

[46]  C. Twohy.  Airborne Condensation Nucleus Counter User's Guide , 1991 .

[47]  P. Quinn,et al.  Interactions between the sulfur and reduced nitrogen cycles over the central Pacific Ocean , 1990 .

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

[49]  D. Lenschow,et al.  Dynamics and Chemistry of Marine Stratocumulus (DYCOMS) Experiment , 1988 .

[50]  Stephen Nicholls,et al.  Observations of marine stratocumulus clouds during FIRE , 1988 .

[51]  S. Warren,et al.  Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate , 1987, Nature.

[52]  S. Nicholls.  The dynamics of stratocumulus: Aircraft observations and comparisons with a mixed layer model , 1984 .

[53]  Tabatabayi Yazdi.  PHYSICOCHEMICAL PROPERTIES , 1981 .

[54]  A. H. Woodcock,et al.  THE PRODUCTION, CONCENTRATION, AND VERTICAL DISTRIBUTION OF THE SEA‐SALT AEROSOL * , 1980 .

[55]  G. L. Stephens,et al.  Radiation Profiles in Extended Water Clouds. I: Theory , 1978 .