Temperature reconstructions and comparisons with instrumental data from a tree-ring network for the European Alps

Abstract

Ring-width and maximum latewood density data from a network of high-elevation sites distributed across the European Alps are used to reconstruct regional temperatures. The network integrates 53 ring-width and 31 density chronologies from stands of four species all located above 1500 m a.s.l. The development and basic climatic response patterns of this network are described elsewhere . The common temperature signal over the study region allowed regional reconstructions to be developed using principal component regression models for average June-August (1600-1988 and April-September (1650-1987 temperatures from ring-width and density records, respectively. Similar climatic histories are derived for both seasons, but with the ring-width and density-based reconstructions seemingly weighted toward carrying more of their variance in the lower and higher frequency domains, respectively. Distinct warm decades are the 1940s, 1860s, 1800s, 1730s, 1660s and the 1610s, and cold decades, the 1910s, 1810s, 1710s, 1700s and the 1690s. Because of the model fitting and the shorter time spans involved, comparisons between the reconstructions with high-elevation instrumental data during the majority of the 1864-1972 calibration period show good agreement. Yet, prior to this period, from which only a few low elevation temperature records are available, a trend divergence between tree-ring and instrumental records is observed. We present evidence that this divergence may be explained by the ring-width data carrying more of an annual rather than warm-season signal in the lower frequency domain. Other factors such as noise, tree-ring standardization, or the more uncertain nature of low-frequency trends in early instrumental records and their homogenization, might help explain this divergence as well.

Cycles and shifts: 1,300 years of multi-decadal temperature variability in the Gulf of Alaska

“…As there are no neighboring stations with which to compare the early Sitka record, and these data were not included in the corrected GHCN record, we hypothesize that the problem may lie in the early instrumental data. Similar observations have also been made in Europe between dendroclimatic reconstructions and long early instrumental records (Hughes et al 1984;Bü ntgen et al 2005;Frank and Esper 2005;Wilson et al 2005).…”

Temperature and precipitation variability in the European Alps since 1500

“…Frank and Esper (2005) present comparisons between Alpine tree-ring based temperature reconstructions and instrumental data. They found that the response of ring-width data is not strictly limited to summer season temperatures, but also carries an annual signal particularly in the lower frequency domain (e.g.…”

Precipitation variability during the past 400 years in the Xiaolong Mountain (central China) inferred from tree rings

“…The ring-width sequences from both sites were found to be highly correlated at this stage, indicative of a common climate signal. It has been suggested that tree-ring series growing within one site may show different climate-growth associations due to micro-environmental conditions (Frank and Esper 2005;Meko 1997;Wilmking et al 2005). For example, tree rings in shaded or concave locations with relatively abundant moisture availability in arid regions may be less sensitive to moisture.…”