The concentrations of particulate Al and total suspended particulate matter (TSP) were measured in surface waters at 42 stations on a cruise from Toyko to Alaska and return during the summer of 1978. The mean particulate Al concentration in early July (5.5 μg kg-1) was almost 8 times higher than in mid-August (0.72 μg kg-1). However, the mean TSP concentration was only twice as high. The high particulate Al concentration in the surface waters during early July was correlated with high atmospheric dust concentrations over this area. This dust was likely transported from the desert regions of central and eastern Asia. The data suggest that atmospheric mineral matter deposited on the ocean surface was removed to deeper waters within 1 month. The temporal variability of atmospheric concentrations and deposition of mineral matter may significantly affect the distributions and fluxes of this material in the North Pacific.