Joseph A MacGregor

Joseph A MacGregor

  • RSCH AST, EARTH SCIENCES REMOTE SENS
  • 301.614.5876
  • NASA/GSFC
  • Mail Code: 615
  • Greenbelt , MD 20771
  • Employer: NASA
  • Brief Bio

    Joe MacGregor is a glaciologist and geophysicist interested in the past, present and future flow of ice sheets. He seeks to understand why ice sheets flow more quickly in some areas than in others, how this flow evolves over time and how we can better observe the controls upon ice flow. These are critical concerns for Earth’s two remaining ice sheets in Greenland and Antarctica, along with ice masses elsewhere in the Solar System. With a diverse set of collaborators at NASA and partner institutions, his current research synthesizes observations from a variety of methods, including airborne radar sounding (e.g., Operation IceBridge), satellite remote sensing (e.g., Landsat, MODIS, InSAR), ground-based surveys (e.g., ice core chemistry, borehole thermometry) and laboratory measurements (e.g., dielectric spectroscopy) to better understand ice sheets.

    Education

    2008 - Ph.D., Geophysics, University of Washington (Seattle, WA)

    2002 - B.S. with honors, Geophysical Engineering, Minor: Public Affairs for Engineers, Colorado School of Mines (Golden, CO)

    Positions/Employment

    5/2018 - Present

    Project Scientist, Operation IceBridge (OIB)

    Cryospheric Sciences Laboratory (Code 615), NASA Goddard Space Flight Center (GSFC), Greenbelt, MD
    3/2016 - 5/2018

    Deputy Project Scientist, OIB

    Code 615, NASA GSFC, Greenbelt, MD
    2/2016 - Present

    Research Physical Scientist

    Code 615, NASA GSFC, Greenbelt, MD
    9/2013 - 2/2016

    Research Associate

    Institute for Geophysics, The University of Texas at Austin (UTIG), Austin, TX
    9/2011 - 8/2013

    Research Scientist Associate V

    UTIG, Austin, TX
    10/2009 - 8/2011

    Postdoctoral Fellow

    UTIG, Austin, TX
    9/2008 - 9/2009

    Research Associate

    Dept. of Geosciences, The Pennsylvania State University, State College, PA

    Awards

    • 2017 - NASA 610 HBG Best Science Paper
    • 2013 - NASA Cryospheric Sciences Most Valuble Player
    • 2011 - UTIG Director's Circle of Excellence
    • 2008 - David A. Johnston Award for Research Excellence

    Professional Service

    Other Professional Information

    Google Scholar page

    Publications

    Refereed

    Kjær, K. H., N. K. Larsen, T. Binder, et al. A. A. Bjørk, O. Eisen, M. A. Fahnestock, S. Funder, A. A. Garde, H. Haack, V. Helm, M. Houmark-Nielsen, K. K. Kjeldsen, S. A. Khan, H. Machguth, I. McDonald, M. Morlighem, J. Mouginot, J. D. Paden, T. E. Waight, C. Weikusat, E. Willerslev, and J. A. MacGregor. 2018. "A large impact crater beneath Hiawatha Glacier in northwest Greenland." Science Advances, 4 (11): eaar8173 [10.1126/sciadv.aar8173]

    Scambos, T., R. Bell, R. Alley, et al. S. Anandakrishnan, D. Bromwich, K. Brunt, K. Christianson, T. Creyts, S. Das, R. DeConto, P. Dutrieux, H. Fricker, D. Holland, J. MacGregor, B. Medley, J. Nicolas, D. Pollard, M. Siegfried, A. Smith, E. Steig, L. Trusel, D. Vaughan, and P. Yager. 2017. "How much, how fast?: A science review and outlook for research on the instability of Antarctica's Thwaites Glacier in the 21st century." Global and Planetary Change, 153: 16-34 [10.1016/j.gloplacha.2017.04.008]

    Kwok, R., N. T. Kurtz, L. Brucker, et al. A. Ivanoff, T. Newman, S. L. Farrell, J. King, S. Howell, M. A. Webster, J. Paden, C. Leuschen, J. A. Macgregor, J. Richter-Menge, J. Harbeck, and M. Tschudi. 2017. "Inter-comparison of snow depth retrievals over Arctic sea ice fromradar data acquired by Operation IceBridge." The Cryosphere, 2571-2593 [10.5194/tc-2017-103]

    MacGregor, J. A., W. T. Colgan, M. A. Fahnestock, et al. M. Morlighem, G. A. Catania, J. D. Paden, and S. P. Gogineni. 2016. "Holocene deceleration of the Greenland Ice Sheet." Science, 351 (6273): 590-593 [10.1126/science.aab1702]

    Cavitte, M. G., D. D. Blankenship, D. A. Young, et al. D. M. Schroeder, F. Parrenin, E. Lemeur, J. A. Macgregor, and M. J. Siegert. 2016. "Deep radiostratigraphy of the East Antarctic plateau: connecting the Dome C and Vostok ice core sites." J. Glaciol., 1-12 [10.1017/jog.2016.11]

    MacGregor, J. A., M. A. Fahnestock, G. A. Catania, et al. A. Aschwanden, G. D. Clow, W. T. Colgan, P. S. Gogineni, M. Morlighem, S. M. Nowicki, J. D. Paden, S. F. Price, and H. Seroussi. 2016. "A synthesis of the basal thermal state of the Greenland Ice Sheet." J. Geophys. Res. Earth Surf., 121: [10.1002/2015jf003803]

    Colgan, W. T., H. Machguth, M. MacFerrin, et al. J. D. Colgan, D. van As, and J. A. Macgregor. 2016. "The abandoned ice-sheet base at Camp Century, Greenland, in a warming climate." Geophysical Research Letters, 43: [10.1002/2016GL069688]

    Koenig, L. S., A. Ivanoff, P. M. Alexander, et al. J. A. MacGregor, X. Fettweis, B. Panzer, J. D. Paden, R. R. Forster, I. Das, J. McConnell, M. Tedesco, C. Leuschen, and P. Gogineni. 2016. "Annual Greenland accumulation rates (2009–2012) from airborne Snow Radar." The Cryosphere, 10: 1739–1752 [10.5194/tcd-9-6697-2015]

    MacGregor, J. A., M. A. Fahnestock, G. A. Catania, et al. J. D. Paden, S. Prasad Gogineni, S. K. Young, S. C. Rybarski, A. N. Mabrey, B. M. Wagman, and M. Morlighem. 2015. "Radiostratigraphy and age structure of the Greenland Ice Sheet." J. Geophys. Res. Earth Surf., 120 (2): 212-241 [10.1002/2014jf003215]

    MacGregor, J. A., J. Li, J. D. Paden, et al. G. A. Catania, G. D. Clow, M. A. Fahnestock, S. P. Gogineni, R. E. Grimm, M. Morlighem, S. Nandi, H. Seroussi, and D. E. Stillman. 2015. "Radar attenuation and temperature within the Greenland Ice Sheet." J. Geophys. Res. Earth Surf., 120 (6): 983-1008 [10.1002/2014jf003418]

    Grimm, R. E., D. E. Stillman, and J. A. MacGregor. 2015. "Dielectric signatures and evolution of glacier ice." Journal of Glaciology, 61 (230): 1159-1170 [10.3189/2015jog15j113]

    Stillman, D. E., J. A. MacGregor, and R. E. Grimm. 2013. "The role of acids in electrical conduction through ice." J. Geophys. Res. Earth Surf., 118 (1): 1-16 [10.1029/2012jf002603]

    Stillman, D. E., J. A. MacGregor, and R. E. Grimm. 2013. "Electrical response of ammonium-rich water ice." Annals of Glaciology, 54 (64): 21-26 [10.3189/2013aog64a204]

    Macgregor, J. A., G. A. Catania, H. Conway, et al. D. M. Schroeder, I. Joughin, D. A. Young, S. D. Kempf, and D. D. Blankenship. 2013. "Weak bed control of the eastern shear margin of Thwaites Glacier, West Antarctica." Journal of Glaciology, 59 (217): 900-912 [10.3189/2013jog13j050]

    Macgregor, J. A., G. A. Catania, M. S. Markowski, and A. G. Andrews. 2012. "Widespread rifting and retreat of ice-shelf margins in the eastern Amundsen Sea Embayment between 1972 and 2011." Journal of Glaciology, 58 (209): 458-466 [10.3189/2012jog11j262]

    MacGregor, J. A., K. Matsuoka, E. D. Waddington, D. P. Winebrenner, and F. Pattyn. 2012. "Spatial variation of englacial radar attenuation: Modeling approach and application to the Vostok flowline." Journal of Geophysical Research: Earth Surface, 117 (F3): [10.1029/2011jf002327]

    Matsuoka, K., J. A. MacGregor, and F. Pattyn. 2012. "Predicting radar attenuation within the Antarctic ice sheet." Earth and Planetary Science Letters, 359-360: 173-183 [10.1016/j.epsl.2012.10.018]

    MacGregor, J. A., S. Anandakrishnan, G. A. Catania, and D. P. Winebrenner. 2011. "The grounding zone of the Ross Ice Shelf, West Antarctica, from ice-penetrating radar." Journal of Glaciology, 57 (205): 917-928.

    MacGregor, J., K. Matsuoka, and M. Studinger. 2009. "Radar detection of accreted ice over Lake Vostok Antarctica." Earth Planet Sci Lett, 282 (1-4): 222-233 [10.1016/j.epsl.2009.03.018]

    MacGregor, J., K. Matsuoka, M. Studinger, E. Waddington, and D. Winebrenner. 2009. "Millennially averaged accumulation rates for the Lake Vostok region inferred from deep internal layers." Annals of Glaciology, 50 (51): 25-34.

    Jacobel, R. W., B. C. Welch, D. Osterhouse, R. Pettersson, and J. A. MacGregor. 2009. "Spatial variation of radar-derived basal conditions on Kamb Ice Stream, West Antarctica." Annals of Glaciology, 50 (51): 10-16 [10.3189/172756409789097504]

    MacGregor, J. A., D. P. Winebrenner, H. Conway, et al. K. Matsuoka, P. A. Mayewski, and G. D. Clow. 2007. "Modeling englacial radar attenuation at Siple Dome, West Antarctica, using ice chemistry and temperature data." Journal of Geophysical Research, 112 (F3): F03008 [10.1029/2006jf000717]

    O'Neal, M. A., M. E. O'Mansky, and J. A. MacGregor. 2005. "Modeling the natural degradation of earthworks." Geoarchaeology, 20 (7): 739-748 [10.1002/gea.20079]

    Non-Refereed

    Brunt, K. M., and J. A. Macgregor. 2015. "What Instruments are Available for Polar Studies?" Eos 96: [10.1029/2015EO026855]

    MacGregor, J. A. 2014. "Cryosphere: Bottom-up restructuring of ice." Nature Geosci 7 (7): 481-482 [10.1038/ngeo2191]

    Grants

    01/01/2016 - 12/31/2018 A peek into the history of the Greenland Ice Sheet using radar layers and modeling, NASA Cryospheric Science
    Co-I
    01/01/2015 - 12/31/2017 New estimates of the oxygen flux into, and its distribution within, Lake Vostok using radar sounding observations, NASA Habitable Worlds
    Co-I
    01/01/2015 - 12/31/2017 Accumulation and flow of the Greenland Ice Sheet during the late Holocene, NASA IceBridge Research
    PI
    01/01/2014 - 12/31/2016 Partitioning of soluble impurities in ice: A foundation for planetary radar exploration, NASA Planetary Geology & Geophysics
    Co-I
    01/01/2014 - 12/31/2014 Accumulation and flow of the Greenland Ice Sheet during the Anthropocene, UT Jackson School of Geosciences Seed Grant Program
    PI
    01/01/2012 - 12/31/2014 A synthetic approach to mapping the thermal state of the bed of the Greenland Ice Sheet and critical boundary conditions for the next generation of ice-sheet models, NASA IceBridge Research
    Post-doc
    01/01/2012 - 12/31/2014 Collaborative Research: A new radiostratigraphy of the Greenland Ice Sheet and critical boundary conditions for the next generation of ice-sheet models, NSF Arctic Natural Sciences
    Post-doc
    01/01/2010 - 12/31/2012 New broadband measurements of the dielectric properties of ice cores: A foundation for planetary radar sounding, NASA Planetary Geology & Geophysics
    Post-doc

    Selected Public Outreach

    Greenland Ice Sheet stratigraphy 2015 - 2015
    http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4249

    NASA SVS animation illustrating collection, tracing and dating of Greenland's internal stratigraphy.

    Professional Societies

    American Geophysical Union, 2002 - Present
    International Glaciological Society, 2002 - Present

    Brief Bio

    Joe MacGregor is a glaciologist and geophysicist interested in the past, present and future flow of ice sheets. He seeks to understand why ice sheets flow more quickly in some areas than in others, how this flow evolves over time and how we can better observe the controls upon ice flow. These are critical concerns for Earth’s two remaining ice sheets in Greenland and Antarctica, along with ice masses elsewhere in the Solar System. With a diverse set of collaborators at NASA and partner institutions, his current research synthesizes observations from a variety of methods, including airborne radar sounding (e.g., Operation IceBridge), satellite remote sensing (e.g., Landsat, MODIS, InSAR), ground-based surveys (e.g., ice core chemistry, borehole thermometry) and laboratory measurements (e.g., dielectric spectroscopy) to better understand ice sheets.

    Publications

    Refereed

    Kjær, K. H., N. K. Larsen, T. Binder, et al. A. A. Bjørk, O. Eisen, M. A. Fahnestock, S. Funder, A. A. Garde, H. Haack, V. Helm, M. Houmark-Nielsen, K. K. Kjeldsen, S. A. Khan, H. Machguth, I. McDonald, M. Morlighem, J. Mouginot, J. D. Paden, T. E. Waight, C. Weikusat, E. Willerslev, and J. A. MacGregor. 2018. "A large impact crater beneath Hiawatha Glacier in northwest Greenland." Science Advances 4 (11): eaar8173 [10.1126/sciadv.aar8173]

    Scambos, T., R. Bell, R. Alley, et al. S. Anandakrishnan, D. Bromwich, K. Brunt, K. Christianson, T. Creyts, S. Das, R. DeConto, P. Dutrieux, H. Fricker, D. Holland, J. MacGregor, B. Medley, J. Nicolas, D. Pollard, M. Siegfried, A. Smith, E. Steig, L. Trusel, D. Vaughan, and P. Yager. 2017. "How much, how fast?: A science review and outlook for research on the instability of Antarctica's Thwaites Glacier in the 21st century." Global and Planetary Change 153 16-34 [10.1016/j.gloplacha.2017.04.008]

    Kwok, R., N. T. Kurtz, L. Brucker, et al. A. Ivanoff, T. Newman, S. L. Farrell, J. King, S. Howell, M. A. Webster, J. Paden, C. Leuschen, J. A. Macgregor, J. Richter-Menge, J. Harbeck, and M. Tschudi. 2017. "Inter-comparison of snow depth retrievals over Arctic sea ice fromradar data acquired by Operation IceBridge." The Cryosphere 2571-2593 [10.5194/tc-2017-103]

    MacGregor, J. A., W. T. Colgan, M. A. Fahnestock, et al. M. Morlighem, G. A. Catania, J. D. Paden, and S. P. Gogineni. 2016. "Holocene deceleration of the Greenland Ice Sheet." Science 351 (6273): 590-593 [10.1126/science.aab1702]

    Cavitte, M. G., D. D. Blankenship, D. A. Young, et al. D. M. Schroeder, F. Parrenin, E. Lemeur, J. A. Macgregor, and M. J. Siegert. 2016. "Deep radiostratigraphy of the East Antarctic plateau: connecting the Dome C and Vostok ice core sites." J. Glaciol. 1-12 [10.1017/jog.2016.11]

    MacGregor, J. A., M. A. Fahnestock, G. A. Catania, et al. A. Aschwanden, G. D. Clow, W. T. Colgan, P. S. Gogineni, M. Morlighem, S. M. Nowicki, J. D. Paden, S. F. Price, and H. Seroussi. 2016. "A synthesis of the basal thermal state of the Greenland Ice Sheet." J. Geophys. Res. Earth Surf. 121 [10.1002/2015jf003803]

    Colgan, W. T., H. Machguth, M. MacFerrin, et al. J. D. Colgan, D. van As, and J. A. Macgregor. 2016. "The abandoned ice-sheet base at Camp Century, Greenland, in a warming climate." Geophysical Research Letters 43 [10.1002/2016GL069688]

    Koenig, L. S., A. Ivanoff, P. M. Alexander, et al. J. A. MacGregor, X. Fettweis, B. Panzer, J. D. Paden, R. R. Forster, I. Das, J. McConnell, M. Tedesco, C. Leuschen, and P. Gogineni. 2016. "Annual Greenland accumulation rates (2009–2012) from airborne Snow Radar." The Cryosphere 10 1739–1752 [10.5194/tcd-9-6697-2015]

    MacGregor, J. A., M. A. Fahnestock, G. A. Catania, et al. J. D. Paden, S. Prasad Gogineni, S. K. Young, S. C. Rybarski, A. N. Mabrey, B. M. Wagman, and M. Morlighem. 2015. "Radiostratigraphy and age structure of the Greenland Ice Sheet." J. Geophys. Res. Earth Surf. 120 (2): 212-241 [10.1002/2014jf003215]

    MacGregor, J. A., J. Li, J. D. Paden, et al. G. A. Catania, G. D. Clow, M. A. Fahnestock, S. P. Gogineni, R. E. Grimm, M. Morlighem, S. Nandi, H. Seroussi, and D. E. Stillman. 2015. "Radar attenuation and temperature within the Greenland Ice Sheet." J. Geophys. Res. Earth Surf. 120 (6): 983-1008 [10.1002/2014jf003418]

    Grimm, R. E., D. E. Stillman, and J. A. MacGregor. 2015. "Dielectric signatures and evolution of glacier ice." Journal of Glaciology 61 (230): 1159-1170 [10.3189/2015jog15j113]

    Stillman, D. E., J. A. MacGregor, and R. E. Grimm. 2013. "The role of acids in electrical conduction through ice." J. Geophys. Res. Earth Surf. 118 (1): 1-16 [10.1029/2012jf002603]

    Stillman, D. E., J. A. MacGregor, and R. E. Grimm. 2013. "Electrical response of ammonium-rich water ice." Annals of Glaciology 54 (64): 21-26 [10.3189/2013aog64a204]

    Macgregor, J. A., G. A. Catania, H. Conway, et al. D. M. Schroeder, I. Joughin, D. A. Young, S. D. Kempf, and D. D. Blankenship. 2013. "Weak bed control of the eastern shear margin of Thwaites Glacier, West Antarctica." Journal of Glaciology 59 (217): 900-912 [10.3189/2013jog13j050]

    Macgregor, J. A., G. A. Catania, M. S. Markowski, and A. G. Andrews. 2012. "Widespread rifting and retreat of ice-shelf margins in the eastern Amundsen Sea Embayment between 1972 and 2011." Journal of Glaciology 58 (209): 458-466 [10.3189/2012jog11j262]

    MacGregor, J. A., K. Matsuoka, E. D. Waddington, D. P. Winebrenner, and F. Pattyn. 2012. "Spatial variation of englacial radar attenuation: Modeling approach and application to the Vostok flowline." Journal of Geophysical Research: Earth Surface 117 (F3): [10.1029/2011jf002327]

    Matsuoka, K., J. A. MacGregor, and F. Pattyn. 2012. "Predicting radar attenuation within the Antarctic ice sheet." Earth and Planetary Science Letters 359-360 173-183 [10.1016/j.epsl.2012.10.018]

    MacGregor, J. A., S. Anandakrishnan, G. A. Catania, and D. P. Winebrenner. 2011. "The grounding zone of the Ross Ice Shelf, West Antarctica, from ice-penetrating radar." Journal of Glaciology 57 (205): 917-928

    MacGregor, J., K. Matsuoka, and M. Studinger. 2009. "Radar detection of accreted ice over Lake Vostok Antarctica." Earth Planet Sci Lett 282 (1-4): 222-233 [10.1016/j.epsl.2009.03.018]

    MacGregor, J., K. Matsuoka, M. Studinger, E. Waddington, and D. Winebrenner. 2009. "Millennially averaged accumulation rates for the Lake Vostok region inferred from deep internal layers." Annals of Glaciology 50 (51): 25-34

    Jacobel, R. W., B. C. Welch, D. Osterhouse, R. Pettersson, and J. A. MacGregor. 2009. "Spatial variation of radar-derived basal conditions on Kamb Ice Stream, West Antarctica." Annals of Glaciology 50 (51): 10-16 [10.3189/172756409789097504]

    MacGregor, J. A., D. P. Winebrenner, H. Conway, et al. K. Matsuoka, P. A. Mayewski, and G. D. Clow. 2007. "Modeling englacial radar attenuation at Siple Dome, West Antarctica, using ice chemistry and temperature data." Journal of Geophysical Research 112 (F3): F03008 [10.1029/2006jf000717]

    O'Neal, M. A., M. E. O'Mansky, and J. A. MacGregor. 2005. "Modeling the natural degradation of earthworks." Geoarchaeology 20 (7): 739-748 [10.1002/gea.20079]

    Non-Refereed

    Brunt, K. M., and J. A. Macgregor. 2015. "What Instruments are Available for Polar Studies?" Eos 96 [10.1029/2015EO026855]

    MacGregor, J. A. 2014. "Cryosphere: Bottom-up restructuring of ice." Nature Geosci 7 (7): 481-482 [10.1038/ngeo2191]

                                                                                                                                                                                            
    NASA Logo, National Aeronautics and Space Administration