Bess Koffman

Education

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.

Recent Publications

2024

[26] Chalif, J., *Jongebloed, U., Osterberg, E.C., Koffman, B.G., Alexander, B., Winski, D.A., *Polashenski, D.J., Stamieszkin, K., Ferris, D., Kreutz, K., Wake, C., Cole-Dai, J, 2024. Industrial-era decline in ice core MSA driven by anthropogenic emissions. Nature Geoscience, doi: 10.1038/s41561-024-01543-w.

[25] Barkley, A.E., Winckler, G., Recasens, C., Kaplan, M.R., Koffman, B.G., Calabozo, F. Middleton, J., Anderson, R.F., Cai, Y., Bolge, L., Longman, J., Goldstein, S.L., 2024. Patagonian dust, Agulhas Current and Antarctic ice rafted debris contributions to the South Atlantic Ocean over the past 150,000 years. Proceedings of the National Academy of Sciences 121 (31) e2402120121, doi: 10.1073/pnas.2402120121.

[24] *Huang, L., Aarons, S.M., and Koffman, B.G., Cheng, W., *Hanschka, L., Munk, L.A., Jenkes, J., Norris, E., and Arendt, C.A., 2024. The role of source, mineralogy, and organic complexation on lability and Fe isotopic composition of terrestrial Fe sources to the Gulf of Alaska.  ACS Earth and Space Sciences, doi:10.1021/acsearthspacechem.3c00338.

[23] Koffman, B.G. and Kreutz, K.J., 2024. Ice Core Methods: Glaciochemistry. Encyclopedia of Quaternary Science, 3^rd edition (S.A. Elias, ed.), Elsevier Publishers, Amsterdam. doi: 10.1016/B978-0-323-99931-1.00196-3.

2023

[22] Koffman, B.G., Osman, M.B., Criscitiello, A., and *Guest, S., 2023. Women’s collaboration helps close the gender gap in ice core science. Nature Geoscience, doi: 10.1038/s41561-023-01315-7.

[21] Bisson, K. M., Gassó, S., Mahowald, N., Wagner, S., Koffman, B., Carn, S. A., Deutsch, S., Gazel, E., Kramer, S., Krotkov, N., Mitchell, C., Pritchard, M. E., Stamieszkin, K., & Wilson, C. 2023. Observing ocean ecosystem responses to volcanic ash. Remote Sensing of Environment, 296, 113749, doi: 10.1016/j.rse.2023.113749.          

[20] Koffman, B.G., Goldstein, S.L., Winckler, G., Kaplan, M.R., Bolge, L., and Biscaye, P. 2023. Abrupt changes in atmospheric circulation during the Medieval Climate Anomaly and Little Ice Age recorded by Sr-Nd isotopes in the Siple Dome ice core, Antarctica. Paleoceanography & Paleoclimatology 38(4), e2022PA004543, doi: 10.1029/2022PA004543. Selected as cover article.

[19] *Chesler, A., Winski, D., Kreutz, K., Koffman, B.G., Osterberg, E.C., Ferris, D., Thundercloud, Z., *Mohan, J., Cole-Dai, J., Wells, M., Handley, M., Putnam, A., *Anderson, K., and *Harmon, N. 2023. Non-spherical microparticle shape in Antarctica during the last glacial period affects dust volume-related metrics. Climate of the Past 19, 477-492, doi: 10.5194/cp-19-477-2023.

2022

[18] Koffman, B.G., *Saylor, P., *Zhong, R., *Sethares, L., *Yoder, M.F., *Hanschka, L., *Methven, T., Cai, Y., Bolge, L., Longman, J., Goldstein, S.L., and Osterberg, E.C. 2022. Provenance of anthropogenic Pb and atmospheric dust to northwestern North America. Environmental Science and Technology, doi: 10.1021/acs.est.2c03767.

2021

[17] Koffman, B.G., *Yoder, M., *Methven, T., *Hanschka, L., *Sears, H., *Saylor, P., and Wallace, K. 2021c. Glacial dust surpasses both volcanic ash and desert dust in its iron fertilization potential. Global Biogeochemical Cycles, 35, e2020GB006821, doi: 10.1029/2020GB006821.

[16] Koffman, B.G., Goldstein, S.L., Winckler, G., Kaplan, M.R., Kreutz, K.J., Bolge, L., Bory, A., and Biscaye, P. 2021b. Late Holocene dust provenance at Siple Dome, Antarctica. Quaternary Science Reviews 274, doi: 10.1016/j.quascirev.2021.107271.

[15] *Lewis, G., Osterberg, E., Hawley, R., Marshall, H.P., Meehan, T., *Graeter, K., McCarthy, F., Overly, T., *Thundercloud, Z., Ferris, D., Koffman, B.G., and Dibb, J. 2021. Atmospheric Blocking Drives Recent Albedo Change Across the Western Greenland Ice Sheet Percolation Zone. Geophysical Research Letters, 48 (10), e2021GL092814. (A top downloaded article)

[14] Koffman, B.G., Goldstein, S.L., Winckler, G., Borunda, A., Kaplan, M.R., Bolge, L., Cai, Y., Recasens, C., Koffman, T.N.B., and Vallelonga, P.T. 2021a. New Zealand as a source of mineral dust to the atmosphere and ocean. Quaternary Science Reviews, 251, doi: 10.1016/j.quascirev.2020.106659.

Datasets

Osterberg, E., Winski, D.A., Kreutz, K.J., Koffman, B., Ferris, D.G., Wake, C., and Handley, M. (2023-05-02): NOAA/WDS Paleoclimatology – Denali Ice Core Major Ion and Trace Metal Data from 801 to 2013 CE. NOAA National Centers for Environmental Information. https://doi.org/10.25921/6cpm-kr44. Accessed 2023-05-02.

Koffman, B. G., Saylor, P., Sethares, L., Yoder, M. F., Hanshka, L., Methven, T., Cai, Y., Bolge, L., Goldstein, S. L., Osterberg, E. C., 2022. Sr-Nd-Pb isotope ratios in snow pits from Denali National Park and sediments from southcentral Alaska, Version 1.0. Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.26022/IEDA/112229. Accessed 2022-03-02.

Koffman, B. G., Goldstein, S. L., Winckler, G., Kaplan, M. R., Kreutz, K. J., Bolge, L., Bory, A., Biscaye, P., 2022. Late Holocene Sr-Nd isotope and REE data from the Siple Dome ice core, Antarctica, Version 1.0. Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.26022/IEDA/112176. Accessed 2021-11-04.

Koffman, B. G., Goldstein, S. L., Winckler, G., Borunda, A., Kaplan, M. R., Bolge, L., Cai, Y., Recasens, C., Koffman, T. N. B., Vallelonga, P. T. 2021. Major/trace element and Sr-Nd-Pb isotope geochemistry of New Zealand South Island sediments, Version 1.0. Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.26022/IEDA/111726. Accessed 2020-10-20.  

Koffman, B.G., Yoder, M.F., Methven, T., Hanschka, L., Sears, H.B., Saylor, P.L., Wallace, K.L., 2021. Geochemistry of sediments and volcanic ash from Southcentral Alaska, Version Version 1.0. Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.26022/IEDA/111679. Accessed 2020-09-17.  

Koffman, B., 2017. Snowpit evidence of the 2011 Puyehue-Cordón Caulle (Chile) eruption in West Antarctica. Palisades, New York USA: U.S. Antarctic Program (USAP) Data Center. doi: 10.15784/601036.

Kreutz, K., and Koffman, B., 2015. WAIS Divide microparticle concentration and size distribution, 0-2400 ka. Boulder, Colorado USA: National Snow and Ice Data Center. doi: 10.7265/N5KK98QZ.

Kreutz, K., and Koffman, B., 2015. Snowpit chemistry – methods comparison, WAIS Divide, Antarctica. Boulder, Colorado USA: National Snow and Ice Data Center. doi: 10.7265/N5Q81B1X.

Kreutz, K., Koffman, B., Breton, D., and Hamilton, G., 2011. Microparticle, Conductivity, and Density Measurements from the WAIS Divide Deep Ice Core, Antarctica. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5K07264.

Kreutz, K., and Koffman, B. 2011. WAIS Divide Snowpit Chemical and Isotope Measurements, Antarctica. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5SJ1HHN.