HR: 0800h
AN: PP51D-0634    [Abstracts]
TI: Past Productivity Variations in the California Current Upwelling System: 0-60 ka BP.
AU: * Lopes, C
EM: clopes@coas.oregonstate.edu
AF: College of Atmospheric and Oceanic Sciences, Oregon State University, 104 COAS Admin. Bldg, Corvallis, OR 97331-5503 United States
AU: Mix, A
EM: amix@coas.oregonstate.edu
AF: College of Atmospheric and Oceanic Sciences, Oregon State University, 104 COAS Admin. Bldg, Corvallis, OR 97331-5503 United States
AU: Orscheln, N
EM: norschel@coas.oregonstate.edu
AF: College of Atmospheric and Oceanic Sciences, Oregon State University, 104 COAS Admin. Bldg, Corvallis, OR 97331-5503 United States
AB: Upwelling systems, such as the California Current, play an important role in the regional response and impacts of climate change. Diatoms from core MD02-2499 off Northern California (41° 39.10 N; 124° 56.25 W; 905 m depth), reveal past changes in the upwelling system in response to climate change over the past 60,000 years, sampled every ~500y. Using Q-mode and Canonical Correspondence (CC) analysis, we defined 6 statistical diatom assemblages reflecting different oceanic conditions and created a transfer function for productivity estimation. Prior to the Last Glacial Maximum (LGM), the Subarctic Front factor decreases and variations reflect interactions amongst factors for fresh water input, subtropical, and transitional floras, with low productivity suggesting low coastal upwelling. After the LGM, production peaked during the Bolling-Allerod warming, associated with a high Subarctic Front factor. In general, highest production is associated with regional warm climate events. By implication, intermittent disoxia on the shelf and slope may in part reflect high production associated with climate warming.
DE: 3030 Micropaleontology (0459, 4944)
DE: 3344 Paleoclimatology (0473, 4900)
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
DE: 4279 Upwelling and convergences (4964)
DE: 4964 Upwelling (4279)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005