DECIPHERING PALEOCLIMATE FROM EOLIAN ACCUMULATIONS IN SOILS OF THE PACIFIC NORTHWEST

General trends in paleoclimate are routinely extracted from soils, whereas discrete temporal records of climate change are rare. The Pacific Northwest (PacNW) offers environmental contexts that are appropriate for the development and exploration of new models that explain soil characteristics in terms of climatic variables. One direction for soil models involves mass-balance considerations of elements/molecules that are sensitive to infiltration, a proxy for precipitation. Approaches developed in some of the world’s wettest and driest environments should be applicable in the PacNW, as they involve balancing influx-efflux of matter and energy with complex reactions and reorganizations within soils. PacNW soils are subject to allocthonous aerosolic influx from continental and marine sources. Far-traveled and regional dust comes central Asia, the Great Basin, and PacNW sources. Along the windward coast of the PacNW, the concentration of marine aerosols and bioaerosols delivered to soils follows a logarithmic cline in deposition far into the continental interior. Additionally having a region populated with conifers, the best-known botanic scavengers of aerosols, will lead to greater influx of aerosols to soils and hence the paleoclimate signature should be more discernable. Challenges ahead include differentiating the various source signatures and making direct links from source to soil (‘sink’). Constrained records of climate change in the source region, should allow that of the soil to be quantified if the signal is strong enough. Soils are in many respects open systems, which introduces much variability, but there are still-to-be-explored sites within soils that could sequester important time information. There is a pressing research need to develop strategies to identify these sites and extract their time-series information. Development of models with field experiments will be an important initial step in realizing soils as holders of paleoclimate records in the PacNW.