NOAA/WDS Paleoclimatology - Hughes and Graumlich 1996 Multi-Millennial Nevada Precipitation Reconstruction

Multimillennial tree-ring chronologies from the mountains of the western United States provide an excellent opportunity to study decade to century scale variability in pre-instrumental times. This results from the lack of ecological interaction between the widely-spaced, climate-sensitive, long-lived trees characteristic of the higher elevations of this region. The availability of climate-sensitive > 1000 year tree-ring records in the western conterminous United States is unique. For example, 80 tree-ring chronologies of at least 1000 years length and 23 of at least 2000 years length, have been developed at our Laboratory for this region. A number of climate reconstructions of high quality have already been published using subsets of these data. The great potential of this resource will be demonstrated by reference to these reconstructions. In particular, we introduce a preliminary reconstruction of precipitation in the Great Basin covering the period 6000 B.C. to A.D. 1979. We will use this to place in context a striking pattern of two multidecade droughts each terminated by intense wet periods in the period between A.D. 900 and 1400.