MARINE-TERRESTRIAL CLIMATE CONNECTIONS: THE INFLUENCE OF THE EASTERN PACIFIC OCEAN ON THREE MIDDLE TO HIGH ELEVATION LAKES AND SAN FRANCISCO BAY

Evidence for a strong connection between the North Pacific Ocean and climate of the western U.S. is found in paleoclimate records from middle and high elevation lakes in California and Nevada, as well as San Francisco Bay.

Medicine Lake (2036 m), in northwestern California, is presently a closed-basin lake that receives most of its water from seasonal snowpack. Comparison with the record from ODP Site 1019, off northern California, demonstrates a significant connection between coastal precipitation and lake level throughout the Holocene. Swamp Lake (1554 m) is a small, middle elevation lake in the northwestern corner of Yosemite National Park. Much of the ~19,000 year record is varved, providing a high-resolution record. Multiple proxies record changes in lake level and productivity during the Medieval Climate Anomaly and Little Ice Age that may allow us to evaluate the impact of Pacific climate patterns such as ENSO and PDO. Located in the Ruby Mountains in northeastern Nevada, Favre Lake (3029 m) is affected by a more complicated set of atmospheric conditions than either of the previously discussed lakes. Preliminary results show some similarities to both Pacific and Rocky Mountain climate records.

San Francisco Bay receives fresh water from more than 40% of California, and therefore provides a record of climate variability over much of the state. Marsh records from the northern bay correspond well with other records of shorter duration allowing a synthesis of late Holocene precipitation records, which indicates that moisture is controlled by conditions in the Pacific Ocean.