JOHN BARRON IN THE HOLOCENE (Invited Presentation)

After studying Cretaceous diatom biostratigraphy between the mid 1970’s and late 1990’s, during the early 2000’s John Barron turned his attention to late Pleistocene and Holocene paleoceanography of the eastern Pacific. Working on nearly every time scale, from years to millennia, he continues to this day to pursue the relatively subtle variations of the most recent interglacial. Paleoclimate of the northeast Pacific margin was known to have varied during the Holocene, but spatial patterns were poorly defined. From the northern Californian margin, to the Gulf of California, Santa Barbara basin, central Oregon and the Gulf of Alaska, John detected both spatial and temporal patterns and recognized they could represent more than noise, but rather fingerprints of underlying causal mechanisms. Looking for further clues, he has recognized and utilized the combined power of terrestrial and marine proxy records. Finding those linkages led to recognizing the role of internal modes of ocean-atmosphere variability and the underappreciated importance of seasonality, including the respective summer versus winter roles of the North American Monsoon and ENSO. Along this path, John has embraced multi-proxy perspectives and engaged future scientists in collaborations to generate hypotheses that are shaping the direction of future research on Holocene hydroclimate of western North America. This talk will focus on compiled evidence from terrestrial and marine archives for North Pacific ocean-atmosphere reorganization between ~4 and 3 ka and implications for understanding climate variability in western North America.