Transport of ice nuclei over the north pacific ocean

Simultaneous measurements have been made over extended periods of time of the relative concentrations of ice nuclei in the air at stations in Alaska, Hawaii and Washington State. On occasions large increases in ice nucleus counts lasting for a week or more (“ice nucleus storms” were observed. The ice nucleus storms sometimes occurred in close proximity in time at different stations and it is shown that in some cases this can be explained by the advection of particles in the lower troposphere between stations. On other occasions the ice nucleus storms appeared to be of local origin.