Bess Koffman

Assistant Professor of Geology, Colby College

External Associate, Climate Change Institute



B.A. Geology, Carleton College
Ph.D. Earth and Climate Sciences, University of Maine
NSF Postdoctoral Fellowship, Lamont-Doherty Earth Observatory of Columbia University
Society of Fellows Postdoctoral Fellowship, Dartmouth College

Areas of Expertise

  • Paleoclimate
  • Sediment geochemistry
  • Ice cores
  • Climate change
  • Radiogenic isotopes
  • Atmospheric dust

Current Research

I study past changes in Earth’s climate system using a combination of field and laboratory approaches. I am interested primarily in understanding how and why the atmospheric circulation has changed through time and the impacts these changes have had on terrestrial and marine environments. Earth’s atmospheric circulation influences large-scale climate variability in several important ways: it affects the transport and delivery of oceanic heat; it exerts a strong influence on the exchange of carbon dioxide (CO2) between the ocean and atmosphere; and it plays a large role in determining global rainfall distribution. Further, because the atmosphere can respond rapidly to climate perturbations, it is central to understanding the mechanisms driving changes in Earth’s climate on a range of timescales. I use mineral dust as a tracer of past wind patterns by measuring the dust particle size distribution (a proxy for distance to source and wind strength) and its geochemical and isotopic composition (to determine provenance and transport pathway). My approach couples high-resolution archives of past environmental change, such as ice core records, with state-of-the-art analyses of dust particle size and composition. My research to date has focused on three major themes: 1) the impact of dust on marine ecosystems, 2) reconstructing past changes in mid-latitude wind belts, and 3) the transport of aerosols from explosive volcanic eruptions.

Colby College Website

Personal Research Website