A Dynamical Perspective on High Altitude Paleoclimate Proxy Timeseries

Abstract

Mountain paleoarchives, including glaciers, laminated lake sediments, and trees near the limits of their habitable range, provide much information relevant to the study of past climatic changes (Alverson and Kull 2002). Properties recorded in these archives offer quantitative climate-related information at annual or higher temporal resolution. In addition, by nature of their occurrence at high elevation, they provide information about climate variability in the free atmosphere, not just its surface expression. However, interpreting these proxy records in terms of large-scale climatic change is a difficult task. Mountains are generally regions of strong climatic gradients and inherently high natural variability, making interpretation of local records difficult. Additional difficulties exist due to the fact that the proxies do not respond to climate alone, but are influenced by myriad additional factors. In this chapter, we highlight two methods which use dynamical constraints, either from the climate system or the underlying archives themselves, to help tease out the climatic information contained in point-based proxy timeseries. Although the examples that we present are applied in conjunction with ice core records, the techniques are relevant to the interpretation of annually resolved climate proxy timeseries in high altitude regions. Past climatic changes are often either reconstructed using paleoproxy data or modeled using a numerical representation of the underlying dynamics of either the climate system or paleoarchive development.