A PACIFIC INTERDECADAL CLIMATE OSCILLATION WITH IMPACTS ON SALMON PRODUCTION

Evidence gleaned from the instrumental record of climate data identifi es a robust, recurring pattern of ocean-atmosphere climate variability centered over the midlatitude North Pacific basin. Over the past cent ury, the amplitude of this climate pattern has varied irregularly at i nterannual-to-interdecadal timescales. Then is evidence of reversals i n the prevailing polarity of the oscillation occurring around 1925, 19 47, and 1977; the last two reversals correspond to dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pat tern also affects coastal sea and continental surface air temperatures , as well as streamflow in major west coast river systems, from Alaska to California.