HR: 11:05h
AN: PP52A-04    [Abstracts]
TI: Drought in the Western US and Floods in China: Pacific Response to Global Warming
AU: * Asmerom, Y
EM: asmerom@unm.edu
AF: Dept. of Earth & Planetary Sciences, The University of New Mexico 200 Yale Blvd NE, Albuquerque, NM 871131, United States
AU: Polyak, V
EM: polyak@unm.edu
AF: Dept. of Earth & Planetary Sciences, The University of New Mexico 200 Yale Blvd NE, Albuquerque, NM 871131, United States
AU: Burns, S
EM: sburns@geo.umass.edu
AF: Department of Geosciences, University of Massachusetts, Amherst, MA 01003, United States
AU: Rasmussen, J
EM: 'jt_rasmussen@mail.utexas.edu'
AF: Institute for Geophysics, University of Texas at Austin, Austin, TX 78758, United States
AB: Regional response to increased warming due to greenhouse forcing is of vital interest and is only now beginning to be explored. . The Pacific Ocean plays an important role in modulating regional climate in many parts of the world at interannual to decadal time-scales; the response of the Pacific to global warming is thus important to any future climate predictions. Currently, there are contradictory modeling inferences on the response of the Pacific to greenhouse warming. One way to resolve these contradictions is to look for analogues to global warming scenarios in the paleoclimate record. Although climate response to solar variability is likely to be different in magnitude and detail compared to greenhouse forcing, it is a potential analog. Solar modulation of Holocene climate has now been documented in a number of regions, including the southwestern US (SW) and the monsoon region of China, based on precipitation records of precisely-dated speleothems. In the SW higher than normal solar activity was associated with drier than normal conditions, typical of La Niña and the negative phase of the PDO. In contrast, higher solar activity was associated with wetter than normal conditions in China. This inverse response to solar forcing by the two regions is attributed to changes in the Walker circulation and the Pacific Decadal and El Niño/Southern Oscillation systems of the Pacific Ocean. The inverse response to solar forcing by the two regions is consistent with modern negative correlation (r = -0.45) of precipitation patterns between the two regions. If solar forcing is indeed a low-level analogue to greenhouse forcing, the speleothem data suggest that warming from greater greenhouse emissions will lead to La Niña and the negative phase of the PDO-like conditions in the Pacific. These conditions would result in greater drought in the western USA and wetter conditions in the monsoon regions of Asia.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1637 Regional climate change
DE: 4914 Continental climate records
DE: 4958 Speleothems
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting