Skip to main content
    • Aa
    • Aa

Climatic Regionalization and the Spatio-Temporal Occurrence of Extreme Single-Year Drought Events (1500–1998) in the Interior Pacific Northwest, USA

  • Paul A. Knapp (a1), Henri D. Grissino-Mayer (a2) and Peter T. Soulé (a3)

Tree-ring records from western juniper (Juniperus occidentalis var. occidentalis Hook.) growing throughout the interior Pacific Northwest identify extreme climatic pointer years (CPYs) (i.e., severe single-year droughts) from 1500–1998. Widespread and extreme CPYs were concentrated in the 16th and early part of the 17th centuries and did not occur again until the early 20th century. The 217-yr absence of extreme CPYs may have occurred during an extended period of low variance in the Pacific Decadal Oscillation. We mapped climatic boundaries for the interior Pacific Northwest based on the location of sites with similar precipitation variability indices. Three regions, the Northwest (based on chronologies from nine sites), the Southwest (four sites), and the East (five sites) were identified. Our results suggest that western juniper radial growth indices have substantial interannual variability within the northwestern range of the species (central Oregon), particularly when compared with western juniper growing in its eastern range (eastern Oregon, southeastern Idaho, and northern Nevada) and southwestern range (southern Oregon and northeast California). We suspect that the substantial differences in the variability of western juniper radial growth indices are linked to the influence of ENSO events on winter/spring precipitation amounts.

Corresponding author
1To whom correspondence should be addressed. E-mail:
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

F. Biondi , A. Gershunov , and D.R. Cayan North Pacific decadal climate variability since 1661. Journal of Climate 14, (2001). 5 10.

G. Bond , B. Kromer , J. Beer , R. Muscheler , M.N. Evans , W. Showers , S. Hoffmann , R. Lotti-Bond , I. Hajdas , and G. Bonani Persistent solar influence on North Atlantic climate during the Holocene. Science 294, (2001). 2130 2136.

M.C. Bridge , P.E. Gasson , and D.F. Cutler Dendroclimatological observations on trees at Kew and Wakehurst Place: Event and pointer years. Forestry 69, (1996). 263 269.

L.B. Brubaker Spatial patterns of tree-growth anomalies in the Pacific Northwest. Ecology 61, (1980). 798 807.

R.B. Cattell The scree test for the number of factors. Multivariate Behavioral Research 1, (1966). 245 276.

R. D'Arrigo , G. Jacoby , M. Free , and A. Robock Northern hemisphere temperature variability for the past three centuries: Tree-ring and model estimates. Climatic Change 42, (1999). 663 667.

T.G.J. Dyer The assignment of rainfall stations into homogeneous groups: An application of principal components analysis. Quarterly Journal of the Royal Meteorological Society 101, (1975). 1005 1013.

B.K. Eder , J.M. Davis , and J.F. Monahan Spatial and temporal analysis of the Palmer Drought Severity Index over the southeastern United States. Journal of Climatology 7, (1987). 31 56.

A. Gershunov , and T.P. Barnett Interdecadal modulation of ENSO teleconnections. Bulletin of the American Meteorological Society 79, (1998). 2715 2725.

A. Gershunov , T. Barnett , and D. Cayan North Pacific interdecadal oscillation seen as factor in ENSO-related North American climate anomalies. EOS, Transactions, American Geophysical Union 80, (1999). 25 30.

L.J. Graumlich Precipitation variation in the Pacific Northwest (1675–1975) as reconstructed from tree-rings. Annals of the Association of American Geographers 77, (1987). 19 29.

H.D. Grissino-Mayer , and H.C. Fritts The International Tree-Ring Data Bank: an enhanced global database serving the global scientific community. The Holocene 7, (1997). 235 238.

M.K. Hughes , and P.M. Brown Drought frequency in central California since 101 B.C. recorded in giant sequoia tree rings. Climate Dynamics 6, (1992). 161 167.

L.K. Kadonaga , O. Podlaha , and M.J. Whiticar Time series analyses of tree ring chronologies from Pacific North America: Evidence for sub-century climate oscillations. Chemical Geology 161, (1999). 339 363.

T.R. Karl , and A.J. Koscielny Drought in the United States: 1895–1981. Journal of Climatology 2, (1982). 313 329.

F.P. Keen Climatic cycles in eastern Oregon indicated by tree-rings. Monthly Weather Review 65, (1937). 175 188.

P.A. Knapp , P.T. Soulé , and H.D. Grissino-Mayer Post-drought growth responses of western juniper (Juniperus occidentalis var. occidentalis) in central Oregon. Geophysical Research Letters 28, (2001). 2657 2660.

P.A. Knapp , P.T. Soulé , and H.D. Grissino-Mayer Detecting potential regional effects of increased atmospheric CO2 on growth rates of western juniper. Global Change Biology 7, (2001). 903 917.

D.J. Leathers , T.L. Mote , K.C. Kuivinen , S. McFeeters , and D.R. Kluck Temporal characteristics of USA snowfall 1945–46 to 1984–85. International Journal of Climatology 13, (1993). 65 76.

N.J. Mantua , S.R. Hare , Y. Zhang , J.M. Wallace , and R.C. Francis A Pacific interdecadal climate oscillation with impacts on salmon production. Bulletin of the American Meteorological Society 78, (1997). 1069 1079.

V.C. Mitchell The regionalization of climate in the western United States. Journal of Applied Meteorology 15, (1976). 920 927.

J. Namias Some causes of United States drought. Journal of Climate and Applied Meteorology 22, (1983). 30 39.

K.T. Redmond , and R.W. Koch Surface climate and streamflow variability in the western United States and their relationship to large-scale circulation indices. Water Resources Research 27, (1991). 2381 2399.

F.H. Schweingruber Tree Rings: Basics and Applications of Dendrochronology. (1988). Reidel, Dordrecht.

P.T. Soulé Spatial patterns of multiple drought types in the contiguous United States: A seasonal comparison. Climate Research 1, (1990). 13 21.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Quaternary Research
  • ISSN: 0033-5894
  • EISSN: 1096-0287
  • URL: /core/journals/quaternary-research
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Abstract views

Total abstract views: 6 *
Loading metrics...

* Views captured on Cambridge Core between 20th January 2017 - 26th March 2017. This data will be updated every 24 hours.