Instrument : Cloud Condensation Nuclei Particle Counter (CCN)

Instrument Categories
Airborne Observations, Aerosols

The cloud condensation nuclei counter (CCN) is a U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility instrument for measuring the concentration of aerosol particles that can act as cloud condensation nuclei [1, 2]. The CCN draws the sample aerosol through a column with thermodynamically unstable supersaturated water vapor that can condense onto aerosol particles. Particles that are activated, i.e., grown larger in this process, are counted (and sized) by an Optical Particle Counter (OPC). Thus, activated ambient aerosol particle number concentration as a function of supersaturation is measured. Models CCN-100 and CCN-200 differ only in the number of humidifier columns and related subsystems: CCN-100 has one column and CCN-200 has two columns along with dual flow systems and electronics.

The CCN is part of the Aerosol Observing System (AOS).

Output Datastreams

  • aosccn : Aerosol Observing System (AOS): cloud condensation nuclei data
  • aosccn100 : Aerosol Observing System (AOS): cloud condensation nuclei data
  • aosccn1col : AOS: Cloud Condensation Nuclei Counter
  • aosccn200 : AOS: Dual Column Cloud Condensation Nuclei Counter
  • noaaaosccn100 : Aerosol Observing System (AOS): cloud condensation nuclei data

Primary Measurements

The following measurements are those considered scientifically relevant.


Eastern North Atlantic
ENAC1 Browse Data Browse PlotsGraciosa Island, Azores, Portugal
North Slope Alaska
NSAX1 Browse Data Browse PlotsExternal Data (satellites and others) retired
Southern Great Plains
SGPC1 Browse Data Browse PlotsCentral Facility, Lamont, OK
SGPS01 Browse Data Browse PlotsSupplemental 1, Lamont, OK
ARM Mobile Facility
ACXM1 Browse Data Browse PlotsOff the Coast of California - NOAA Ship Ronald H. Brown; AMF2
ASIM1 Browse Data Browse PlotsAscension Island, South Atlantic Ocean; AMF1
AWRM1 Browse DataMcMurdo Station Ross Ice Shelf, Antarctica; AMF2
FKBM1 Browse DataBlack Forest, Germany retired
GRWM1 Browse DataGraciosa Island, Azores, Portugal; AMF1 retired
HFEM1 Browse DataShouxian, Anhui, China retired
MAGM1 Browse Data Browse PlotsLos Angeles, CA to Honolulu, HI - container ship Horizon Spirit; AMF2 retired
MAOM1 Browse DataManacapuru, Amazonas, Brazil; AMF1
NIMM1 Browse DataNiamey, Niger retired
PGHM1 Browse DataARIES Observatory, Nainital, Uttarkhand, India; AMF1 retired
PVCM1 Browse DataHighland Center, Cape Cod MA; AMF1 retired
PYEM1 Browse DataPoint Reyes, CA retired
SBSS2 Browse Data Browse PlotsSteamboat Springs CO, Christie Peak retired
TMPS1 Browse Data Browse PlotsU. of Helsinki Research Station (SMEAR II), Hyytiala, Finland; AOS
 retired = Originating instrument has been retired at this location

See Also


Cynthia Salwen
Brookhaven National Laboratory

Janek Uin
Brookhaven National Laboratory

Gunnar Senum
Brookhaven National Laboratory
(631) 344-3896

Stephen Springston
Brookhaven National Laboratory
(631) 344-4477

Anne Jefferson
(303) 497-6493