| This dissertation investigated the influence of atmospheric / oceanic variability on streamflow in the continental United States. Unimpaired streamflow for stations in the continental United States and, interdecadal and interannual Pacific Ocean (e.g., El Nino-Southern Oscillation and Pacific Decadal Oscillation) and Atlantic Ocean (e.g., Atlantic Multidecadal Oscillation and North Atlantic Oscillation) climatic variability were identified. Initially, the coupled effects of climatic variability on continental U.S. streamflow, based on the long-term phase (warm / positive or cold / negative) of the interdecadal variable, were identified using nonparametric statistical testing. Next, sea surface temperature variability in the Pacific and Atlantic Oceans, and the resulting continental U.S. streamflow variability, were identified using Singular Value Decomposition. Finally, Pacific and Atlantic Ocean sea surface temperatures (SSTs) were used as predictors in a long lead-time streamflow forecast model applying Partial Least Squares Regression.; The major contributions of this dissertation are threefold. First, an evaluation was performed to identify the interdecadal PDO, AMO and NAO's influence on U.S. streamflow, focusing on how each enhanced or dampened the interannual ENSO. This resulted in several new observations, including the enhancement of La Nina during an AMO warm phase in the Southeastern United States. Next, Pacific and Atlantic Ocean SST impacts on continental U.S. streamflow, based on the long-term phase of the interdecadal PDO or AMO, were evaluated. This resulted in a significant relationship between variability in SST and streamflow based on the warm or cold phase of the interdecadal influence. Finally, Pacific and Atlantic Ocean SSTs were utilized and a long lead-time, streamflow forecast model was developed. The use of SSTs resulted in excellent forecast skill for several rivers in the continental United States. The results of this dissertation, including the identification of climatic influences and forecasting of continental U.S. streamflow, will provide useful information to water managers and planners. |
