A tree-ring perspective on the extreme wetness of the early 1900’s in the western United States [abstract]

Ring-width indices from 136 sites in the area from northern Montana to southern New Mexico between latitudes 103°W and 111°W were examined to infer periods of anomalous wetness for the years 1700-1964. Sites were grouped into north, central and south regions, and the gross regional tree-ring fluctuations were compared. The results indicate that the period 1905-1917 was unique in the 265-year record for the combined magnitude, duration, and north/south coherence of the growth anomaly of much lesser magnitude occurred in the 1830's-1840's [sic]. Both this and the 1905-1917 anomaly appear from time-series plots to be manifestations of low-frequency growth variations at wave lengths between about 20 and 60 years.

Hydrologic variability related to El Nino in the Pacific Northwest [abstract]

A preliminary statistical analysis was undertaken to evaluate whether the effect of El Nino events is apparent in variables related to hydrologic behavior. Annual precipitation, temperature and streamflow were used for three locations in Oregon representing coastal, Willamette Valley/Cascade and eastern Oregon regions. The mean and variance for periods of El Nino occurrence vs. those with no El Nino were computed. Numerical differences were observed but were not consistent across all stations. The coastal area showed a decrease in mean precipitation and increase in mean streamflow during El Nino events. Other stations showed a positive increase in mean for both precipitation and streamflow for El Nino events. Variance of precipitation was greater in the coastal area but smaller in other areas and vice versa for streamflow during El Nino events. Statistical analyses indicated no significant differences of means, variances or distributions using nonparametric tests for El Nino vs. non-El Nino series.

On the trail of interannual variability in phytoplankton and climate [abstract and figures]

EXTRACT (SEE PDF FOR FULL ABSTRACT): A selective but nontheless real record of phytoplankton activity over the Santa Barbara Basin can be obtained from the underlying varved sediments. The phytoplankton groups preserved are: diatoms (frustrules and spores), silicoflagellates, dinoflagellates (cysts) and coccoliths.

Annual stream flow variability over the western United States [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The variability of mean annual streamflow over the western United States is described and related to indices of large scale atmospheric circulation over the Pacific Ocean and western U.S. Principal component analysis reveal [sic] four statistically significant modes of streamflow variability across the region.