The mass accumulation rate and grain size of the total colian component isolated from pelagic sediment in two North Pacific cores, piston core KK75-02 under the prevailing westerlies and Deep-Sea Drilling Project Site 503 beneath the trade winds, have been used to evaluate changes in the intensity of atmospheric circulation and source-area aridity over the past 700,000 yr. The eolian grain size, a direct indicator of wind intensity, fluctuates at periodicities similar to those calculated for the earth's orbital parameters of precession, obliquity, and eccentricity. Both sites display greater variability in wind intensity prior to 250,000 yr ago. Eolian accumulation rates, an indicator of source-area aridity, fluctuate at periodicities similar to those of the glacial-interglacial cycles. Lower eolian accumulation rates during colder (glacial) times most likely reflect increased glacial-age humidity at central Asian and Central American source areas.

The depth and age of the Brunhes/Matuyama reversal at KK75-02 were taken from Hammond et al. (1979, doi:10.1016/0012-821X(79)90166-3) and Mankinen and Dalrymple (1979, doi:10.1029/JB084iB02p00615), respectively. Age estimates of the radiolarian datum levels are from Morley ef al. (1982, doi:10.1016/0198-0149(82)90038-3). The carbonate curve at Hole 503B was interpolated from Gardner (1982, doi:10.2973/dsdp.proc.68.110.1982). Assigned ages for the carbonate boundaries are from Shackleton and Opdyke (1976).

Supplement to: Janecek, Thomas R; Rea, David K (1985): Quaternary fluctuations in the northern hemisphere trade winds and westerlies. Quaternary Research, 24(2), 150-163