Sizes and Amounts of CCN

  • Note: 1 cm3 is about the size of your thumb!!!

  • Total mass of CCN put into atmosphere each year is about 2x1012 kg!!!!

  • Two types of CCN:

    • Hygroscopic - water seeking - H2O readily condenses on these

      • ocean salt is a good example (sticky salt shaker when humid)

    • Hydrophobic- water repellant - H2O does not readily condense on these (wax on car)
Type of Particle Approximate Radius (mm) # of Particles per cm3

range (typical)
Small CN (Aitken) < 0.2 1000-10000(1000)
Large CN 0.2 - 1.0 1-1000(100)
Giant CN > 1.0 <1 to 10 (1)
Fog and cloud droplets > 10.0 10-1000(300)