Some effects of climate variability on hydrology in western North America

The strong north-south gradient in precipitation along the West Coast makes this region an interesting laboratory for studying the influence of climate on runoff variability in general and riverine chemistry in particular. Interannual fluctuations in large-scale atmospheric circulation and associated precipitation and runoff can produce major disruptions in the "average" climatologic picture. Such fluctuations can be inferred and simplified from the time-averaged atmospheric pressure field and large-scale patterns of stream flow anomalies (eg., high or low stream flow). Further, the effect of the climate gradient along western United States on the total dissolved solids concentrations in rivers is summarized as a highly idealized force-response model of total dissolved solids concentrations as a function of river flow. The response in wet years is more like the wetter climate response curves observed to the north and the response in dry years is more like the drier response curves observed to the south.