HR: 0800h
AN: H51A-1109    [Abstracts]
TI: Climatic Controls on Western U.S. River Discharge: ENSO, PDO and ???
AU: * Farnsworth, K L
EM: klfarn@wm.edu
AF: College of William and Mary Dept. of Geology, PO BOX 8795, Williamsburg, VA 23185 United States
AU: Milliman, J
EM: milliman@vims.edu
AF: Virginia Institute of Marine Science, PO BOX 1346, Gloucester Pt., VA 23062 United States
AB: 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.
DE: 3022 Marine sediments--processes and transport
DE: 1815 Erosion and sedimentation
DE: 1860 Runoff and streamflow
DE: 1625 Geomorphology and weathering (1824, 1886)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting