Natalie M. Kehrwald
(she/her)Dr. Natalie Kehrwald is a Research Geologist at the Geosciences and Environmental Change Science Center in Denver, Colorado. She came to the USGS after working as a Research Scientist at the Ca’ Foscari University of Venice. Dr. Kehrwald was awarded the Marie Sklowdowska Curie post-doctoral fellowship to work with the Italian National Research Council.
Dr. Kehrwald studies interactions between climate, fire and humans using biomarkers in ice cores and sedimentary records. Droughts and vegetation changes can affect fuel availability, and changing atmospheric conditions can alter the number of natural fire ignitions through lightning strikes. Humans are particularly adept at setting fires both for survival (cooking, warmth, and land clearance) but also often accidentally ignite wildfires. Paleoclimate records such as lake cores and ice cores provide detailed records of fire activity, variations in precipitation, changing vegetation and human activity through time, and help place recent droughts and wildfires into the context of a longer timescale.
Professional Experience
2015 - present: Research Geologist, Geosciences and Environmental Change Science Center, USGS, Denver, Colorado
2011 - 2015: Research Scientist, Department of Environmental Sciences, Informatics and Statistics, University of Venice, Italy
2009 - 2011: Marie Curie Post-Doctoral Fellow, Italian National Research Council (CNR-IPDA), Italy
2009: Visiting Assistant Professor, Geology Department, Colorado College
1999 - 2001: U.S. Peace Corps, Environmental Engineer, Bolivia
Education and Certifications
PhD, Earth Sciences, The Ohio State University, 2009
MS, Geosciences, University of Massachusetts Amherst, 2004
BA, Environmental Science/Geology, Colorado College, 1999
Science and Products
Anthropogenic impact in the Mayan Lowlands of Petén, Guatemala, during the last 5500 years
Prospects for reconstructing paleoenvironmental conditions from organic compounds in polar snow and ice
One thousand years of fires: Integrating proxy and model data
Fire in the Earth System: Bridging data and modeling research
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Publications
Filter Total Items: 16
Anthropogenic impact in the Mayan Lowlands of Petén, Guatemala, during the last 5500 years
Trace and rare earth elements from a Lake Peten Itzá (Guatemala) sediment core depict the geochemical dynamics affecting the lake from ~5500 y BP to the present. This timing encompasses the Preclassic (4000 to 1700 y BP) and Classic Periods (1700-1000 y BP) when thriving Maya societies extensively cleared land for agriculture. We demonstrate that this land use occurred during times of increased prAuthorsD. Battistel, Marco Roman, A Marchetti, Natalie M. Kehrwald, Marta Radaelli, Eleanora Balliana, Giuseppina Toscano, Carlo BarbanteProspects for reconstructing paleoenvironmental conditions from organic compounds in polar snow and ice
Polar ice cores provide information about past climate and environmental changes over periods ranging from a few years up to 800,000 years. The majority of chemical studies have focused on determining inorganic components, such as major ions and trace elements as well as on their isotopic fingerprint. In this paper, we review the different classes of organic compounds that might yield environmentaAuthorsChiara Giorio, Natalie M. Kehrwald, Carlo Barbante, Markus Kalberer, Amy C.F. King, Elizabeth R. Thomas, Eric W. Wolff, Piero ZennaroOne thousand years of fires: Integrating proxy and model data
The current fires raging across Indonesia are emitting more carbon than the annual fossil fuel emissions of Germany or Japan, and the fires are still consuming vast tracts of rainforest and peatlands. The National Interagency Fire Center (www.nifc.gov) notes that 2015 is one worst fire years on record in the U.S., where more than 9 million acres burned -- equivalent to the combined size of MassachAuthorsNatalie M. Kehrwald, Julie C. Aleman, Michael Coughlan, Colin J. Courtney Mustaphi, Esther N. Githumbi, Brian I. Magi, Jennifer R. Marlon, Mitchell J. PowerFire in the Earth System: Bridging data and modeling research
Significant changes in wildfire occurrence, extent, and severity in areas such as western North America and Indonesia in 2015 have made the issue of fire increasingly salient in both the public and scientific spheres. Biomass combustion rapidly transforms land cover, smoke pours into the atmosphere, radiative heat from fires initiates dramatic pyrocumulus clouds, and the repeated ecological and atAuthorsSrijn Hantson, Silvia Kloster, Michael Coughlan, Anne-Laure Daniau, Boris Vanniere, Tim Bruecher, Natalie M. Kehrwald, Brian I. MagiNon-USGS Publications**
Van Marle, M.J.E.; Kloster, Silvia; Magi, B.I.; Marlon, J.R.; Daniau, Anne-Laure; Field, R.D.; Arneth, Almut; Forrest, Matthew; Hantson, Stijn; Kehrwald, N.M.; Knorr, Wolfgang; Lasslop, Gitta; Li, Fang; Mangeon, Stéphane; Yue, Chao; Kaiser, J.W.; and van der Werf, G.R., 2017, Historic global biomass burning emissions for CMIP6 (BB4CMIP) based on merging satellite observations with proxies and fire models (1750-2015): Geoscientific Model Development, v. 10, iss. 9.Battistel, D., Argiriadis, E., Kehrwald, N., Spigariol, M., Russell, J.M., Barbante, C., 2017, Fire and human record at Lake Victoria, East Africa during the Early Iron Age: Did humans or climate cause massive ecosystem changes?: The Holocene, DOI: 10.1177/0959683616678466Gabrielli, P., Barbante, C., Bertagna, G., Merto, M., Binder, D., Carton, A., Carturan, L., Cazorzi, F., Cozzi, C., Dalla Dontana, G., Davis, M., De Blasi, F., Dinale, R., Draga, G., Dreossi, G., Festi, D., Frezzotti, M., Gabrieli, J., Galos, S.P., Ginot, P., Heidenwolf, P., Jenk, T.M., Kehrwald, N.M., Kenny, D., Magand, O., Mair, V., Mikhalenko, C., Lin, P.N., Oeggl, K., Piffer, G., Rinaldi, M., Schotterer, U., Schwikowski, M., Seppi, R., Spolaor, A., Stenni, B., Tonidandel, D., Uglietti, C., Zagorodnov, V., Zanoner, T., Sennaro, P., 2016, Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum: Cryosphere, 10, 6, 2779-2797, DOI:10.5194/tc-10-2779-2016Brovkin, V, Brücher, T., Kleinen, T., Zaehle, S., Joos, F., Roth, R., Spahni, R., Schmitt, J., Fischer, H., Leuenberger, M., Stone, E., Ridgewell, A., Chappellaz, J., Kehrwald, N., Barbante, C., Blunier, T., Dahl Jensen, D., 2016, Comparative carbon cycle dynamics of past and present interglacials: Quaternary Science Reviews, 137, 15-32, DOI/10.1016/j.quascirev.2016.01.028Zangrando, R., Barbaro, E., Vecchiato, M., Kehrwald, N., Barbante, C., Gambaro, A., 2016, Levoglucosan and phenols in marine, coastal and inland Antarctic aerosols: Science of the Total Environment, 544, 606-616, doi:10.1016/j.scitotenv.2015.11.166Zennaro, P., N. Kehrwald, J. Marlon, W. F. Ruddiman, T. Brücher, C. Agostinelli, D. Dahl-Jensen, R. Zangrando, A. Gambaro, and C. Barbante, 2015, Europe on fire three thousand years ago: Arson or climate?: Geophys. Res. Lett., 42, 5023–2033. doi: 10.1002/2015GL064259.Schüpbach, S., Kirchgeorg, T., Colombaroli, D., Beffa, G., Radaelli, M., Kehrwald, N., Barbante, C., 2015, Combining charcoal sediment and molecular markers to infer a Holocene fire history in the Maya lowlands of Petén, Guatemala: Quaternary Science Reviews 05/2015; 115. DOI:10.1016/j.quascirev.2015.03.004Portenga, E.W., Bierman, P.R., Duncan, C., Corbett, L.B., Kehrwald, N.M., Rood, D.H., 2015, Erosion rates of the Bhutanese Himalaya determined using in situ-produced 10Be: Geomorphology, 233, 122-126 doi:0.1016/j.geomorph.2014.09.027Kehrwald, N., Zennaro, P., Schüpbach, S., Kirchgeorg, T., McConnell, J.R., Zangrando, R., Gambaro, A., Barbante, C., 2015, Two thousand years of boreal biomass burning recorded in the NEEM ice cores: PAGES Magazine Vol. 23, 1, 14-15Wang, N., Xiaobo, W., Kehrwald, N., Li, Z., Li, Q., Jiang, X., Pu, J., 2015, Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits: PloS ONE, 10 (2) e0116580Gabrielli, P, Hardy, D.R., Kehrwald, N., Davis, M., Cozzi, G., Turetta, C., Barbante, C., Thompson, L.G., 2014, Deglaciated areas of Kilimanjaro as a source of volcanic trace elements deposited on the ice cap during the late Holocene: Quaternary Science Reviews, 93, 1-10, DOI:10.1016/j.quascirev.2014.03.007Guo, Z., Wang, N., Kehrwald, N.M., Mao, R., Wu, H., Wu, Y., Jiang, X., 2014, Temporal and spatial changes in Western Himalayan firn line altitudes from 1998 to 2009: Global and Planetary Change, 118, 97-105. DOI: 10.1016/j.gloplacha.2014.03.012Kirchgeorg, T., Schüpbach, S. Kehrwald, N., McWethy, D., Barbante, C., 2014, Method for determining levoglucosan, mannosan and galactosan in sediment to reconstruct past fire activity: Organic Geochemistry, 71, 1-6, DOI:10.1016/j.orggeochem.2014.02.014Zennaro, P., Kehrwald, N., McConnell, J., Schüpbach, S, Masselli, O., Marlon, J., Zangrando, R., Vallelonga, P., Spolaor, A., Varin, C., Borrotti, M., Gambaro, A., Barbante, B., 2014, Fire in ice: two millennia of Northern Hemisphere fire history from the Greenland NEEM ice core: Climate of the Past, 10, 1905–1924, 2014 www.clim-past.net/10/1905/2014/ doi:10.5194/cp-10-1905-2014
Kehrwald, N., Whitlock, C., Barbante, C., Brovkin, V., Daniau, A-L-. Kaplan, J.O., Marlon, J.R., Power, M.J., Thomicke, K., Van der Werf, G., 2013, Fire Research: Linking Past, Present and Future Data: EOS, Vol. 94, No. 46, 12 November 2013, DOI: 10.1002/2013EO460001Barbante, C., Kehrwald, N., Marianelli, P., Vinther, B. M.,Cozzi, G., Hammer, C., Clausen, H., Siggard Andersen, M., 2013, Greenland ice core evidence of the 79 AD Vesuvius eruption: Climate of the Past, 9, 1221–1232, 2013 www.clim-past.net/9/1221/2013/ doi:10.5194/cp-9-1221-2013Spolaor, A., Vallelonga, P., Plane, J.M.C, Kehrwald N., Gabrieli J., Varin C., Turetta C., Cozzi G., Boutron C. and Barbante C., 2013, Halogen species record Antarctic sea ice over glacial-interglacial periods: Atmospheric Chemistry and Physics, 13, 6623–6635, 2013 www.atmos-chem-phys.net/13/6623/2013/ doi:10.5194/acp-13-6623-2013
Spolaor A., Vallelonga P., Gabrieli J., Kehrwald N., Turetta C., Cozzi G., Poto L., Plane J.M.C., Boutron C.F., Barbante C., 2013, Speciation analysis of iodine and bromine at picogram-per-gram levels in polar ice: Analytical and Bioanalytical Chemistry, DOI: 10.1007/s00216-012-5806-0Zangrando, R., Barbaro, E., Zennaro, P., Rossi, S., Kehrwald, N.M., Gabrieli, J., Barbante, C., Gambaro, A., 2013, Biomass burning molecular markers in Arctic aerosols: Environmental Science and Technology, 47, 8565−8574, dx.doi.org/10.1021/es400125rKirchgeorg, T., Dreyer, A., Gabrieli, J., Kehrwald, N., Sigl, M., Schwikowski, M., Boutron, C., Gambaro, A., Barbante, C., Ebinghaus, R., 2013, Temporal Variations of Perfluoroalkyl Substances and Polybromintad Diphenyl Ethers in Alpine Snow: Environmental Pollution 178, 367-374.Spolaor, A., Vallelonga, P., Cozzi, G., Gabrieli, J., Varin, C., Kehrwald, N., Zennaro, P., Boutron, C., Barbante, C., 2013, Iron speciation influences iron bioavailability over glacial-interglacial cycles: Geophysical Research Letters, 40, 8, 618–1623, DOI: 10.1002/grl.50296Poto, L., Gabrieli, J., Crowhurst, S., Appleby, P.G., Ferretti, P., Zaccone, C., Surian, N., Ferretti, P., Cozzi, G., Turetta, C., Kehrwald, N.M., Barbante, C., 2013, The first continuous last Late Glacial - Holocene peat bog record from the Dolomites (NE Italian Alps): Quaternary International, http://dx.doi.org/10.1016/j.quaint.2013.05.001Kehrwald, N., P. Zennaro, Barbante, C., 2013, Biomass burning records over the present and past interglacial periods: PAGES News, 21, 1Kehrwald, N., Zangrando, R., Gabrielli, P., Barbante, C., Gambaro, A., 2012, Levoglucosan as a specific marker of fire events in Greenland snow: Tellus B, 64, May. 2012. Available at: http://www.tellusb.net/index.php/tellusb/article/view/18196Scalabrin, E., Zangrando, R., Barbaro, E., Kehrwald, N, Gabrieli, J., Barbante, C., Gambaro, A., 2012, Amino acids in Arctic aerosols: Atmospheric Chemistry and Physics 12, 10453-10463, doi:10.5194/acp-12-10453-2012
Gabrielli, P., Barbante, C., Carturan, L., Cozzi, G., Dalla Fontana, G., Dinale, R., Draga, G., Gabrieli, J., Kehrwald, N., Mair, V., Mikhalenko, G., Seppi, R., Spolaor, A., Thompson, L.G., Tonidandel, D., 2012, Discovery of cold ice in a deep drilling site in the Eastern European Alps: Geografia Fisica e Dinamica Quaternaria, 35, 101-105, Doi: 10.4461/GFDQ.2012.35.10
Gabrieli, J., Carturan, L., Gabrielli, P., Kehrwald, N., Turetta, C., Cozzi, G., Spolaor, A., Dinale, R., Staffler, H., Seppi, R., Dalla Fontana, G., Thompson, L.G., Barbante, C., 2011, Impact of Po Valley emissions on the highest glacier of the Eastern European Alps: Atmospheric Chemistry and Physcis, 11, 15, 80-87-8102, Doi:10.5194/acp-11-8087-2011
Kehrwald, N., McCoy, W., Thibeault, J., Burns, S., Oches, E., 2010, Paleoclimatic implications of modern and LGM European land-snail shell δ18O: Quaternary Research 74, 1, 167-177.Kehrwald, N., Zangrando, R., Gambaro, A., Barbante, C., 2010, Fire and climate: Biomass burning recorded in ice and lake cores: European Physical Journal, 9, 105-114, Doi: 10.1051/epjconf/201009008
Kehrwald, N., Zangrando, R., Gambaro, A., Cescon, P., Barbante, C., 2010, Specific molecular markers in ice cores provide large-scale patters in biomass burning: PAGES News, 18, 2Fortner, S., Fountain, A., Lyons, W., Welch, K., Kehrwald, N., 2009, Trace element and major ion concentrations and dynamics in glacier snow and melt: Eliot Glacier, Oregon Cascades: Hydrological Processes, 23, 2987-2996.
Kehrwald, N.M., Thompson, L.G., Yao, T., Mosley-Thompson, E., Schotterer, U., Alfimov, V., Beer, J., Eikenberg, J., Davis, M.E., 2008, Mass loss on Himalayan glacier endangers water resources: Geophysical Reserch Letters, 35, L22503, doi:10.1029/2008GL035556
Gardner, T., Marshall, J., Merritts, D., Bee, B., Burgette, R., Burton, E., Cooke, J.,Kehrwald, N., Protti, M., Fisher, D., Sak, P., 2001, Holocene forearc block rotation in response to seamount subduction, southeastern Peninsula, Costa Rica: Geology, 29, 2, 151-154.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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