Coralline red algae as recorders of mid- and higher-latitute paleoclimates

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"Climate" is defined as the statistics of weather, and is often quantified for things like monthly averaged temperature and precipitation. While climate has often seemed random and unpredictable, recent advances in climate science point to regularly occurring patterns that impose some order on the climate system. The El Niño, for instance, is the best known "natural pattern" of Earth's climate. This and other climate patterns have characteristic signatures in seasonally changing patterns of wind, air temperature, and precipitation; each pattern also has a typical life time for any given "event". Climate models attempt to predict these patterns and typical life times. Reliable climate models require long-term and high-resolution records of past environmental conditions from different settings. Such data can enable climate forecasts and estimate the human impact on climate. However, instrumental records of environmental variables are limited. This is especially true for mid- and higher latitude oceans, where multicentury reconstructions of intraannual and seasonal marine climate variability are scarce. High-resolution paleoclimate data from these regions are essential as input for global climate models, and necessary in order to distinguish natural and anthropogenically induced climate variability. My research is therefore aimed at generating and interpreting multicentury climate records using geologic climate archives. This proposal will focus on the extraction of climate information from coralline red algae. Coralline red algae, which live in shallow seas, are well suited as recorders of past climates outside the tropics because they (1) are widely distributed in extratropical oceans, (2) are long-lived, and (3) display annual growth increments (similar to tree rings) in a calcified skeleton. Over the next five years I plan to generate multicentury climate reconstructions from the Bering Sea and Northwestern Atlantic- two key regions where poorly understood climate and ecosystem changes have recently had a dramatic impact on fishery yields. The climate reconstructions are expected to yield information on past climate variability, strength and frequency of climate oscillations, and aid in predicting future climate evolution.