Ice Nuclei, Total Aerosol, and Climatology at Mauna Loa, Hawaii

Abstract

The simultaneous operation of two NCAR ice nuclei counters and an integrating nephelometer at Mauna Loa Observatory over a period of 9 months shows concentration changes in the ice nuclei population that vary in direct relation to the atmospheric light scattering coefficient. Furthermore, both of these atmospheric parameters are strongly correlated with local climatology. 1) lowest values of ice nuclei concentrations and Rayleigh scattering exist when subsiding air or a strong temperature inversion prevents the advection of sub-inversion air to the monitoring site; 2) an increased frequency of higher ice nuclei counts and Increased light scattering over a period of several hours are found when mesoscale atmospheric mixing occurs; and 3) the highest number of ice nuclei and maximum light scatter are encountered when a thermally induced air flow advects sub-inversion air to the Observatory site. These findings suggest the absence of extraterrestrial sources for light scattering and ice nucleating material, and point toward the existence of sources for both on Hawaii.