HR: 1330h
AN: PP52A-0962 [PDF]
TI: Linkages Between Hemispheric and Regional Circulation Features Over the Past Millennium Inferred From a
Network of Long Tree-Ring Chronologies in the Southwestern USA.
AU: * Ni, F
EM: fenbiao@ltrr.arizona.edu
AF: Laboratory of Tree-Ring Research, University of Arizona, 105 W. Stadium, Tucson, AZ 85721 United States
AU: Hughes, M K
EM: mhughes@ltrr.arizona.edu
AF: Laboratory of Tree-Ring Research, University of Arizona, 105 W. Stadium, Tucson, AZ 85721 United States
AU: Funkhouser, G
EM: gary@ltrr.arizona.edu
AF: Laboratory of Tree-Ring Research, University of Arizona, 105 W. Stadium, Tucson, AZ 85721 United States
AB:
Features of large-scale atmospheric/oceanic circulation at hemispheric and regional scale affect the many moisture-sensitive,
well-replicated millennial length tree-ring records in the Western US that span all the last millennium. This tree-ring
variability may be associated with the Pacific Decadal Oscillation (PDO), the Southern Oscillation Index (SOI) and the
Southwest Trough Index, all of which directly influence climate variations in the American Southwest. 1000-year
atmospheric/oceanic time series based in these associations were then linked with the observed and previously reconstructed
summer Palmer Drought Severity Index (PDSI) in western US, providing a decadal to multi-century perspective on
climate/circulation variability. Hemispheric and regional climate association tend to be stronger during sudden reversals
from dry to wet which were not uncommon throughout the millennium, such as the 1970s PDO reversal which followed the 1950s
drought, the 1610s wet interval that followed the 16th century mega drought, and the late 11th, early 12th centuries. Proxy
and instrumental data suggest that significant regional anomalous dry (wet) periods over the last millennium (for example in
the 1580s and 1950s) coincided with infrequent (frequent) short-wave trough activity. This probably teleconnected with cold
sea surface temperature (SST) and high sea level pressure (SLP) over the eastern North Pacific that was enhanced by a greater
number of in-phase cold-ENSO and PDO events.
DE: 1812 Drought
DE: 3309 Climatology (1620)
DE: 3344 Paleoclimatology
DE: 4221 Dendrochronology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting