July temperature during the second millennium reconstructed from Idaho tree rings

An 858-year proxy record of July temperature for east-central Idaho shows multi-decadal periods of extreme cooling centered around AD 1300, 1340, 1460, and after AD 1600. These cold intervals are interrupted by prolonged warm spells in the early 1400s, late 1500s, and in the 1930s. The spatial signature of the paleoclimate record is centered on the north-central Rockies and central Great Plains, and expands over North America following a wave-like pattern. Neither instrumental nor proxy data in Idaho northeast valleys show unusual warming during the twentieth century. Climate episodes over the last three centuries are in broad agreement with the Greenland borehole temperature history. Low-frequency patterns are consistent with other northern hemisphere tree-ring records for the late Holocene, and provide a chronology of warm and cold intervals during the Little Ice Age.

[1]  P. Jones,et al.  Unusual twentieth-century summer warmth in a 1,000-year temperature record from Siberia , 1995, Nature.

[2]  P. Jones,et al.  Tree-Ring Density Reconstructions of Summer Temperature Patterns across Western North America since 1600 , 1992 .

[3]  E. Cook,et al.  THE SMOOTHING SPLINE: A NEW APPROACH TO STANDARDIZING FOREST INTERIOR TREE -RING WIDTH SERIES FOR DENDROCLIMATIC STUDIES , 1981 .

[4]  S. Idso,et al.  Detecting the aerial fertilization effect of atmospheric CO2 enrichment in tree‐ring chronologies , 1993 .

[5]  A. Schimmelmann,et al.  A Large California Flood and Correlative Global Climatic Events 400 Years Ago , 1998, Quaternary Research.

[6]  M R Rose,et al.  Increasing Atmospheric Carbon Dioxide: Tree Ring Evidence for Growth Enhancement in Natural Vegetation , 1984, Science.

[7]  J. Guiot,et al.  The Bootstrapped Response Function , 1991 .

[8]  Malcolm K. Hughes,et al.  Global Temperature Patterns , 1998, Science.

[9]  C. Mallows.  More comments on C p , 1995 .

[10]  K. Mosegaard,et al.  Past temperatures directly from the greenland ice sheet , 1998, Science.

[11]  M. Barbetti,et al.  Climatic Change in Tasmania Inferred from a 1089-Year Tree-Ring Chronology of Huon Pine , 1991, Science.

[12]  F. H. Schweingruber,et al.  Influence of volcanic eruptions on Northern Hemisphere summer temperature over the past 600 years , 1998, Nature.

[13]  T. Swetnam,et al.  A dendroecological assessment of whitebark pine in the Sawtooth Salmon River region, Idaho , 1996 .

[14]  Robert G. Quayle,et al.  A Historical Perspective of U.S. Climate Divisions , 1996 .

[15]  Malcolm K. Hughes,et al.  Global-scale temperature patterns and climate forcing over the past six centuries , 1998, Nature.

[16]  S. Wells,et al.  Short-Duration Holocene Lakes in the Mojave River Drainage Basin, Southern California , 1992, Quaternary Research.

[17]  G. Zielinski,et al.  Global influence of the AD 1600 eruption of Huaynaputina, Peru , 1998, Nature.

[18]  Edward R. Cook,et al.  The 'segment length curse' in long tree-ring chronology development for palaeoclimatic studies , 1995 .

[19]  C. L. Mallows.  Some comments on C_p , 1973 .

[20]  G. Jacoby,et al.  Mongolian Tree Rings and 20th-Century Warming , 1996, Science.

[21]  V. Lamarche,et al.  Paleoclimatic Inferences from Long Tree-Ring Records , 1974, Science.

[22]  Benjamin D. Santer,et al.  Estimates of low frequency natural variabilit in near-surface air temperature , 1996 .

[23]  Fritz H. Schweingruber,et al.  Fennoscandian summers from ad 500: temperature changes on short and long timescales , 1992 .

[24]  R. Bradley,et al.  'Little Ice Age' summer temperature variations: their nature and relevance to recent global warming trends , 1993 .

[25]  Claude N. Williams,et al.  A Model to Estimate the Time of Observation Bias Associated with Monthly Mean Maximum, Minimum and Mean Temperatures for the United States , 1986 .

[26]  Fritz H. Schweingruber,et al.  Tree-ring based reconstruction of summer temperatures at the Columbia Icefield, Alberta, Canada, AD 1073-1983 , 1997 .