HR: 09:30h
AN: PP21E-07    [Abstracts]
TI: The Atlantic Multidecadal Oscillation: Origins and Associations
AU: * Kushnir, Y
EM: kushnir@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Seager, R
EM: rich@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Naik, N H
EM: naomi@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Velez, J
EM: jennie@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AB: The Atlantic Multidecadal Oscillation (AMO) is the name used to refer to low-frequency basin-wide sea surface temperature (SST) variability in the North Atlantic. The AMO has often been associated with variability of the Atlantic thermohaline circulation and as such has implications for climate variability from the distant past to the future. Recently the AMO received renewed attention as implicated in the multidecadal variability of hydrological variables such as rainfall and streamflows in North America. This attention has come at the same time that some general circulation model experiments have pointed at tropical Pacific SST as the forcing agent of North American droughts and pluvials. These contrasting views should be reconciled. In this work we attempt to accomplish two goals: (1) revisit our previous work on the AMO in the early 1990ˆs and complement it using more extensive and better analyzed SST data and (2) address the apparent conflict between the two views on the role of the oceans in North America hydrological variability on decadal and multidecadal time scales. Most perplexing in this respect is our finding that an ensemble of coupled GCM integrations forced with historical tropical Pacific SST exhibit AMO-like fluctuations with high temporal coherence to the observed phenomenon. This suggests that both the AMO and North American may be forced from the Pacific and that dictates their observed association.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1833 Hydroclimatology
DE: 4922 El Nino (4522)
DE: 4928 Global climate models (1626, 3337)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005