Climatic Controls on Western U.S. River Discharge: ENSO, PDO and ???
Abstract
River discharge of west coast rivers is strongly tied to both ENSO and PDO. Discharge of southern Californian rivers is positively correlated with El Nino and warm PDO, whereas northwest rivers are positively correlated with La Nina and cold PDO. Central and northern Californian rivers represent a transition from southern to northern climates. These correlation coefficients, however, explain only a relatively small portion of the interannual variability. While event discharge (defined as the top 1% daily discharges over the past 50 years) reflects the above climatic signals, mean annual discharges do not. As an extreme example, mean annual discharge of the Nehalem (Oregon) and Skagit (Washington) rivers is essentially the same during El Nino and La Nina years, as well as during cold and warm PDO years. Clearly another climatic signal must be a major driver in precipitation and river runoff. We suggest that it may be coastal surface water temperature, perhaps combined with wind direction and intensity.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.H51A1109F
- Keywords:
-
- 3022 Marine sediments: processes and transport;
- 1815 Erosion and sedimentation;
- 1860 Runoff and streamflow;
- 1625 Geomorphology and weathering (1824;
- 1886)