Atmospheric Radiation Measurement Climate Research Facility US Department of Energy



Colorado: Ice Nuclei and Cloud Condensation Nuclei Characterization

15 November 2010 - 25 April 2011

Lead Scientist: Daniel Cziczo

Observatory: AMF, SBS

The relationship between aerosol particles and the formation of clouds is among the most uncertain aspects in our current understanding of climate change. Warm clouds have been the most extensively studied, in large part because they are normally close to the Earth’s surface and only contain large concentrations of liquid droplets. Ice and mixed-phase clouds have been less studied even though they have extensive global coverage and dominate precipitation formation. Because they require low temperatures to form, both cloud types are infrequently found at ground level resulting in more difficult field studies. Complex mixtures of liquid and ice elements, normally at much lower concentrations than found in warm clouds, require precise separation techniques and accurate identification of phase. Because they have proved so difficult to study, the climatic impact of ice-containing clouds remains unresolved.

In this study we performed (1) inertial and phase separation of ice crystals and liquid droplets from unactivated aerosol and (2) initiate nucleation of ice crystals and liquid droplets using cloud chambers. We analyzed the aerosol particles within crystals and droplets to determine the size and composition of the precursors to cloud formation. In collaboration with the StormVEx scientists our goal was to relate these findings to the cloud characteristics and the effect of anthropogenic activities.

Campaign results were published Atmos. Chem. Phys., 13, 11839-11851, 2013.

SBS Data Sources

Name Full Name Browse Data
AOD Aerosol Optical Depth, derived from atmospheric extinction of solar irradiance Browse Data
AOSMET Meteorological Measurements associated with the Aerosol Observing System Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CEIL Ceilometer Browse Data
CPC Condensation Particle Counter Browse Data
CSPHOT Cimel Sunphotometer Browse Data
ECOR Eddy Correlation Flux Measurement System Browse Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation Browse Data
HSRL High Spectral Resolution Lidar Browse Data
MET Surface Meteorological Instrumentation Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MPL Micropulse Lidar Browse Data
MWR Microwave Radiometer Browse Data
MWR3C Microwave Radiometer, 3 Channel Browse Data
MWRRET MWR Retrievals Browse Data
NEPHELOMETER Nephelometer Browse Data
OZONE Ozone Monitor Browse Data
PSAP Particle Soot Absorption Photometer Browse Data
QCRAD Data Quality Assessment for ARM Radiation Data Browse Data
RWP Radar Wind Profiler Browse Data
SEBS Surface Energy Balance System Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEADJUST Sonde Adjust Browse Data
SWACR W-Band (95 GHz) ARM Cloud Radar, mounted to scan Browse Data
TSI Total Sky Imager Browse Data