A comparison of late-Holocene hydrologic variability in California: Regionality of multi-decadal to centennial-scale droughts

This study compares the paleohydrologic variability in two California regions over the last 2000 years – Sierra Nevada region and southern California region. Both regions show significant and reproducible proxy evidence for multi-decadal wet/dry intervals that are synchronous between the two regions. The overall durations of individual cycles (wet-wet or dry-dry) average ~130 years, but the cycles are closer to 90–100 year duration for the last 500 years and more than 200 years in duration 1500–2000 years ago. This pattern of varying cyclicity is ongoing today and appears to be related to the intrinsic regional climate variability of the Pacific/California margin.