A reconstructed Siberian High index since A. D. 1599 from Eurasian and North American tree rings

D'Arrigo, R., Jacoby, G., Wilson, R. and Panagiotopoulos, F. (2005) A reconstructed Siberian High index since A. D. 1599 from Eurasian and North American tree rings. Geophysical Research Letters, 32 (5). L05705. ISSN 0094-8276 doi: 10.1029/2004gl022271

Abstract/Summary

The long-term variability of the Siberian High, the dominant Northern Hemisphere anticyclone during winter, is largely unknown. To investigate how this feature varied prior to the instrumental record, we present a reconstruction of a Dec-Feb Siberian High (SH) index based on Eurasian and North American tree rings. Spanning 1599-1980, it provides information on SH variability over the past four centuries. A decline in the instrumental SH index since the late 1970s, related to Eurasian warming, is the most striking feature over the past four hundred years. It is associated with a highly significant (p < 0.0001) step change in 1989. Significant similar to 3-4 yr spectral peaks in the reconstruction fall within the range of variability of the East Asian winter monsoon (which has also declined recently) and lend further support to proposed relationships between these largescale features of the climate system.