Archive for the «Publications» Category

  • Optimized Compton fitting and modeling for light element determination in micro-X-ray fluorescence map datasets

    O’Neil, L.P., D.C. Cating, and W.T. Elam, “Optimized Compton fitting and modeling for light element determination in micro-X-ray fluorescence map datasets,” Nucl. Instrum. Methods Phys. Res., Sect. B, 436, 173-178, doi:10.1016/j.nimb.2018.09.023, 2018.

    The Planetary Instrument for X-ray Lithochemistry (PIXL) is an X-ray fluorescence instrument scheduled to fly to Mars on NASA’s 2020 rover (Allwood et al., 2015). It will be capable of quantifying elements with an atomic number of at least 11 using X-ray fluorescence (XRF), but the detector window blocks fluorescence from lighter elements. Important elements otherwise invisible include carbon, oxygen, and nitrogen, which can make up anions in minerals of scientific interest. X-rays scattered by all elements can be detected, so the ratio of Compton to Rayleigh scatter may be measured and used to infer the presence of elements for which there is no detectable fluorescence. We have refined a fundamental parameters model to predict the Compton/Rayleigh ratio for any given composition that can be compared to an experimentally measured ratio. We compare with a published Monte Carlo model (Schoonjans et al., 2012) and to experimental values for a set of seven materials. Compton/Rayleigh ratios predicted by the model are in good, though imperfect, agreement with experimental measurements. A procedure for consistently computing the Compton/Rayleigh ratio from a noisy spectrum has also been developed using a variation on a common background removal method and peak fitting.


  • In-situ X-ray fluorescence to investigate iodide diffusion in opalinus clay: Demonstration of a novel experimental approach

    Jaquenoud, M., and 9 others including W.T. Elam, “In-situ X-ray fluorescence to investigate iodide diffusion in opalinus clay: Demonstration of a novel experimental approach,” Chemosphere, 269, doi:10.1016/j.chemosphere.2020.128674, 2021.

    During the last two decades, the Mont Terri rock laboratory has hosted an extensive experimental research campaign focusing on improving our understanding of radionuclide transport within Opalinus Clay. The latest diffusion experiment, the Diffusion and Retention experiment B (DR-B) has been designed based on an entirely different concept compared to all predecessor experiments. With its novel experimental methodology, which uses in-situ X-ray fluorescence (XRF) to monitor the progress of an iodide plume within the Opalinus Clay, this experiment enables large-scale and long-term data acquisition and provides an alternative method for the validation of previously acquired radionuclide transport parameters.

    After briefly presenting conventional experimental methodologies used for field diffusion experiments and highlighting their limitations, this paper will focus on the pioneer experimental methodology developed for the DR-B experiment and give a preview of the results it has delivered thus far.


  • Avoiding slush for hot-point drilling of glacier boreholes

    Hill’s, B.H., D.P. Winebrenner, W.T. Elam, and P.M.S. Kintner, “Avoiding slush for hot-point drilling of glacier boreholes,” Ann. Glaciol., 62, 166-170, doi:10.1017/a0g.2020.70, 2021.

    Water-filled boreholes in cold ice refreeze in hours to days, and prior attempts to keep them open with antifreeze resulted in a plug of slush effectively freezing the hole even faster. Thus, antifreeze as a method to stabilize hot-water boreholes has largely been abandoned. In the hot-point drilling case, no external water is added to the hole during drilling, so earlier antifreeze injection is possible while the drill continues melting downward. Here, we use a cylindrical Stefan model to explore slush formation within the parameter space representative of hot-point drilling. We find that earlier injection timing creates an opportunity to avoid slush entirely by injecting sufficient antifreeze to dissolve the hole past the drilled radius. As in the case of hot-water drilling, the alternative is to force mixing in the hole after antifreeze injection to ensure that ice refreezes onto the borehole wall instead of within the solution as slush.


  • Regehr, E. V., M. C. R., Andrew Von Duyke, Ryan R Wilson, Lori Polasek, Karyn D Rode, Nathan J Hostetter, Sarah J
    Converse. 2021. Demographic risk assessment for a harvested species threatened by climate change: polar bears in the
    Chukchi Sea. Ecological Applications 0000:0000.

  • Regehr, E. V., M. Dyck, S. Iverson, D. S. Lee, N. J. Lunn, J. M. Northrup, M.‐C. Richer, G. Szor, and M. C. Runge. 2021.
    Incorporating climate change in a harvest risk assessment for polar bears Ursus maritimus in Southern Hudson Bay.
    Biological Conservation

  • Mudge, M.C., Nunn, B.L., Firth, E., Ewert, M., Hales, K., Fondrie, W.E., Noble, W.S., Toner, J., Light, B. and Junge, K.A., 2021. Subzero, saline incubations of Colwellia psychrerythraea reveal strategies and biomarkers for sustained life in extreme icy environments. Environmental Microbiology.

  • Rode, K. D., E. V. Regehr, J. F. Bromaghin, R. R. Wilson, M. S. Martin, J. A. Crawford, and L. T. Quakenbush. Seal body
    condition and atmospheric circulation patterns influence polar bear body condition, recruitment, and feeding ecology in
    the Chukchi Sea. Global Change Biology:18.

  • Laidre, K. L., S. N. Atkinson, E. V. Regehr, H. L. Stern, E. W. Born, Ø. Wiig, N. J. Lunn, M. Dyck, P. Heagerty, and B. R.
    Cohen. 2020. Transient benefits of climate change for a high‐Arctic polar bear (Ursus maritimus) subpopulation. Global
    Change Biology 26:6251‐6265.

  • King, M. D., Howat, I. M., Candela, S. G., Jeong, S., Noh, M. J., Noël, B., van den Broeke, M. R., Wouters, B., and Negrete, A.: Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat. Nature Communications Earth & Environment, 1,1 (2020).

  • King, M. D., Veron, D. E., and Huntley, H. S.: Early predictors of seasonal Arctic sea ice volume loss: The impact of spring and early-summer cloud radiative conditions. Annals of Glaciology. 1–9. (2020).

  • Rode, K. D., T. C. Atwood, G. W. Thiemann, M. St Martin, R. R. Wilson, G. M. Durner, E. V. Regehr, S. L. Talbot, G. K. Sage,
    A. M. Pagano, and K. S. Simac. 2020. Identifying reliable indicators of fitness in polar bears. PLoS ONE 15:27.

  • Kwok, R., G. F. Cunningham, S. Kacimi, M. A. Webster, N. T. Kurtz, and A. A. Petty, (2020) Decay of the snow cover over Arctic sea from ICESat-2 acquisitions during summer melt in 2019, Geophys. Res. Lett.,

  • Donohoe, A., K.C. Armour, G.H. Roe and D.S. Battisti (2020). The partitioning of atmospheric energy transport and changes under climate forcing in coupled climate models. Journal of Climate.  DOI: 10.1175/JCLI-D-19-0797.1

  • Donohoe, A., E.J. Dawson, L. McMurdie, D.S. Battisti and A. Rhines (2020). Seasonal asymmetries in the lag between insolation and surface temperature. Journal of Climate.  DOI: 10.1175/JCLI-D-19-0329.1

  • Donohoe, A., E. Blanchard-Wrigglesworth., A. Schweiger, P. Rasch (2020). The effect of atmospheric transmissivity on model and observational estimates of the sea ice albedo feedback. Journal of Climate.  DOI: 10.1175/JCLI-D-19-0674.1.

  • Kwok, R., S. Kacimi, M. Webster, N. T. Kurtz, A. A. Petty (2020), Arctic snow depth and sea ice thickness from ICESat-2 and CryoSat-2 freeboards: A first examination,  125(3). doi:10.1029/2019jc016008

  • Zhang, J., Spitz, Y. H., Steele, M., Ashjian, C., Campbell, R., & Schweiger, A. (2020). Biophysical consequences of a relaxing Beaufort Gyre. Geophysical Research Letters, n/a(n/a). doi:10.1029/2019gl085990

  • Laidre, K. L., S. Atkinson, E. V. Regehr, H. L. Stern, E. W. Born, Ø. Wiig, N. J. Lunn, and M. Dyck. 2020. Interrelated
    ecological impacts of climate change on an apex predator. Ecological Applications 30:18.

  • Baxter, I., Ding, Q., Schweiger, A., L’Heureux, M., Baxter, S., Wang, T., . . . Lu, J. (2019). How Tropical Pacific Surface Cooling Contributed to Accelerated Sea Ice Melt from 2007 to 2012 as Ice Is Thinned by Anthropogenic Forcing. Journal of Climate, 32(24), 8583-8602. doi:10.1175/JCLI-D-18-0783.1

  • Moore, G. W. K., Schweiger, A., Zhang, J., & Steele, M. (2019). Spatiotemporal Variability of Sea Ice in the Arctic’s Last Ice Area. Geophysical Research Letters, 46(20), 11237-11243. doi:10.1029/2019gl083722

  • Donohoe, A.Atwood, A. R., & Byrne, M. P. ( 2019). Controls on the width of tropical precipitation and its contraction under global warmingGeophysical Research Letters469958– 9967.

  • Yang, Q., Mu, L., Wu, X., Liu, J., Zheng, F., Zhang, J., Li, C., 2019. Improving Arctic sea ice seasonal outlook by ensemble prediction using an ice-ocean model. Atmospheric Research, 227, pp. 14-23.

  • Smith, M. and Thomson, J., 2019. Ocean surface turbulence in newly formed marginal ice zonesJournal of Geophysical Research: Oceans124(3), pp.1382-1398. doi: 10.1029/2018JC014405

  • Kwok, R., T. Markus, N. T. Kurtz, A. A. Petty, T. A. Neumann, S. L. Farrell. G. F. Cunningham, D. W. Hancock, A. Ivanoff, and J. T. Wimert (2019), Surface height and sea ice freeboard of the Arctic Ocean frosm ICESat-2, Characteristics and early results. J. Geophys. Res. Oceans. doi:10.1029/2019JC015486

  • T. C. Sutterley, T. Markus, T. Neumann, M. van den Broeke, J. M. van Wessem and S. Ligtenberg. Antarctic Ice Shelf Thickness Change from Multi-Mission Lidar Mapping. The Cryosphere, 2019.

  • Schweiger, A.J., K.R. Wood, and J. Zhang, 2019: Arctic Sea Ice Volume Variability over 1901–2010: A Model-Based Reconstruction. J. of Climate, 32, 4731-4752,

  • Mack, S. L., Dinniman, M. S., Klinck, J., McGillicuddy, D. J., and Padman, L.. (2019), Modeling ocean eddies on Antarctica’s cold water continental shelves and their effects on ice shelf basal melting. J. Geophys. Res. Oceans, 124.

  • Hill, David F., E. A. Burakowski, R. L. Crumley, J. Keon, J. M. Hu, A. A. Arendt, K. Wikstrom Jones, and G. J. Wolken, Converting snow depth to snow water equivalent using climatological variables. The Cryosphere, 13, 1767–1784,, 2019.

  • Laurence, G., Burgess, D., Copland, L., Langley, K., Gogineni, P., Paden, J., Leuschen, C., van As, D., Fausto, R., Joughin, I., Smith, B. (2019), Measuring Height Change Around the Periphery of the Greenland Ice Sheet With Radar Altimetry. Frontiers in Earth Science, 7:146. doi:10.3389/feart.2019.00146

  • Liu, Z., & Schweiger, A., 2019. Low-level and surface wind jets near sea ice edge in the Beaufort Sea in late autumn. Journal of Geophysical Research: Atmospheres, 124, 6873– 6891.

  • Hale, J. R., Laidre, K. L., Tinker, M. T., Jameson, R. J., Jeffries, S. J., Larson, S. E. and Bodkin, J. L. (2019), Influence of occupation history and habitat on Washington sea otter diet. Mar Mam Sci. doi:10.1111/mms.12598

  • Armour, K.C., N. Siler, A. Donohoe, and G.H. Roe, 2019: Meridional Atmospheric Heat Transport Constrained by Energetics and Mediated by Large-Scale Diffusion. J. Climate, 32, 3655–3680,

  • Yoon, Y., Kumar, S. V., Forman, B. A., Zaitchik, B. F., Kwon, Y., Qian, Y., Rupper, S., Maggioni V., Houser P., Kirschbaum D., Richey A., Arendt A., Mocko D., Jacob J., Bhanja S., Mukherjee A. (2019) Evaluating the Uncertainty of Terrestrial Water Budget Components Over High Mountain Asia. Frontiers in Earth Science, 7,

  • Peterson, P.K., Hartwig, M., May, N.W., Schwartz, E., Rigor, I., Ermold, W., Steele, M., Morison, J.H., Nghiem, S.V. and Pratt, K.A., 2019. Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry. Elem Sci Anth, 7(1), p.14. DOI:

  • Østerhus, S., Woodgate, R., Valdimarsson, H., Turrell, B., de Steur, L., Quadfasel, D., Olsen, S. M., Moritz, M., Lee, C. M., Larsen, K. M. H., Jónsson, S., Johnson, C., Jochumsen, K., Hansen, B., Curry, B., Cunningham, S., and Berx, B.: Arctic Mediterranean exchanges: a consistent volume budget and trends in transports from two decades of observations, Ocean Sci., 15, 379-399,, 2019
  • Sathe, S., Orellana, M. V., Baliga, N. S. and Durand, P. M. (2019), Temporal and metabolic overlap between lipid accumulation and programmed cell death due to nitrogen starvation in the unicellular chlorophyte Chlamydomonas reinhardtii. Phycological Res., 67: 173-183. doi:10.1111/pre.12368

  • Frantz, C. M., Light, B., Farley, S. M., Carpenter, S., Lieblappen, R., Courville, Z., Orellana, M. V., and Junge, K.: Physical and optical characteristics of heavily melted “rotten” Arctic sea ice, The Cryosphere, 13, 775-793,, 2019.
  • Vargas Zeppetello, L. R.Donohoe, A., & Battisti, D. S. (2019). Does surface temperature respond to or determine downwelling longwave radiation? Geophysical Research Letters462781– 2789

  • Winebrenner, D. P.Kintner, P. M. S., & MacGregor, J. A. (2019). New estimates of ice and oxygen fluxes across the entire lid of Lake Vostok from observations of englacial radio wave attenuationJournal of Geophysical Research: Earth Surface124795–811.

  • Whiteman, J. P., H. J. Harlow, G. M. Durner, E. V. Regehr, S. C. Amstrup, and M. Ben-David. 2019. Heightened Immune System Function in Polar Bears Using Terrestrial Habitats. Physiological and Biochemical Zoology 92:1-11.

  • Kvile, K., C. Ashjian, Z. Feng, J. Zhang, and R. Ji, Pushing the limit: Resilience of an Arctic copepod to environmental fluctuations. Glob Change Biol. 2018; 24:5426-5439.

  • Moore, G.W.K., A. Schweiger, J. Zhang, and M. Steele, What caused the remarkable February 2018 North Greenland Polynya? Geophys. Res. Lett., 45,, 2018.

  • King, M. D., Howat, I. M., Jeong, S., Noh, M. J., Wouters, B., Noël, B., and van den Broeke, M. R.: Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet,The Cryosphere, 12, 3813-3825, (2018).

  • Junge, K., Cameron, K. and Nunn, B., 2019. Diversity of Psychrophilic Bacteria in Sea and Glacier Ice Environments—Insights Through Genomics, Metagenomics, and Proteomics Approaches. In Microbial Diversity in the Genomic Era (pp. 197-216). Academic Press.

  • Wiig, Ø., Henrichsen, P., Sjøvold, T., Born, E.W., Dietz, R., Sonne, C.,  and Aars, J. (2019). Variation in non-metrical skull traits of polar bears (Ursus maritimus) and relationships across East Greenland and adjacent subpopulations (1830–2013). Polar Biology 42:3, 461-474.

  • E. Ciracì, I. Velicogna and T. C. Sutterley. Mass Balance of Novaya Zemlya Archipelago, Russian High Arctic, Using Time-Variable Gravity from GRACE and Altimetry Data from ICESat and CryoSat-2. Remote Sensing, 10(11): 1817, 2018.

  • Regehr, E.V., Hostetter, N.J., Wilson, R.R., Rode, K.D., St. Martin, M., Converse, S.J. (2018), Integrated Population Modeling Provides the First Empirical Estimates of Vital Rates and Abundance for Polar Bears in the Chukchi Sea. Scientific Reports. 8: 16780,

  • Laidre K. L.,  H. Stern, E. W. Born, P. Heagerty, S, Atkinson, Ø. Wiig, N. J. Lunn, E. V. Regehr, R. McGovern, M. Dyck. 2018.  Changes in winter and spring resource selection by polar bears Ursus maritimus in Baffin Bay over two decades of sea-ice loss. Endangered Species Research 36:1-14.

  • Laidre K. L., E. W. Born, S. N. Atkinson, Ø. Wiig, L. W. Andersen, N. J. Lunn, M. Dyck, E. V. Regehr, R. McGovern and P. Heagerty. 2018.  Range contraction and increasing isolation of a polar bear subpopulation in an era of sea ice loss. Ecology and Evolution DOI: 10.1002/ece3.3809

  • Hauser, D.D.W., K.L. Laidre, H.L. Stern, R.S. Suydam, P.R. Richard. 2018. Indirect effects of sea ice loss on summer-fall habitat and behaviour for sympatric populations of an Arctic marine predator. Diversity and Distributions