PT  - JOURNAL ARTICLE
AU  - Esper, Jan
AU  - Cook, Edward R.
AU  - Schweingruber, Fritz H.
TI  - Low-Frequency Signals in Long Tree-Ring Chronologies for Reconstructing Past Temperature Variability
AID  - 10.1126/science.1066208
DP  - 2002 Mar 22
TA  - Science
PG  - 2250--2253
VI  - 295
IP  - 5563
4099  - http://science.sciencemag.org/content/295/5563/2250.short
4100  - http://science.sciencemag.org/content/295/5563/2250.full
SO  - Science2002 Mar 22; 295
AB  - Preserving multicentennial climate variability in long tree-ring records is critically important for reconstructing the full range of temperature variability over the past 1000 years. This allows the putative “Medieval Warm Period” (MWP) to be described and to be compared with 20th-century warming in modeling and attribution studies. We demonstrate that carefully selected tree-ring chronologies from 14 sites in the Northern Hemisphere (NH) extratropics can preserve such coherent large-scale, multicentennial temperature trends if proper methods of analysis are used. In addition, we show that the average of these chronologies supports the large-scale occurrence of the MWP over the NH extratropics.