Water isotopes and ice cores as indicators of climate change: Integrating

data, modeling and theory

David P. Schneider

NCAR

Boulder, CO USA

Stable isotope ratios of precipitation (“del 18-O” and “del D”) preserved

in ice cores record climate variability across a wide range of spatial and

temporal scales. A conceptual model represents the isotopic signature of

precipitation as a history of moisture source conditions, rainout and

advection. As such there is potentially a rich amount of climate

information that can be extracted from ice core records. However, the

complexity of the system, in addition to sources of noise from

synoptic-scale weather and post-depositional alterations can confound the

simple interpretation of records from a single site. It is generally no

long in favor to interpret isotopic records solely as indicators of local

temperature. The challenge is to extract the maximum amount of

climatologically meaningful information from a limited amount of uncertain

data. Here, we discuss the methods and tools that ice core

paleoclimatologists are increasingly applying to the reconstruction of

climate from ice cores. These include using multiple parameters and fine

sampling resolution to produce more reliably dated records, analyzing

isotopic “fields” from a large network of geographically distributed

records, including isotopic tracer code in general circulation models, and

the potential application of inverse methods to take advantage of both the

models and broader array of available data.