Matthew Alkire

Matthew Alkire

Matt’s research interests include: (1) the use of chemical tracers (salinity, δ18O, total alkalinity, barium, nutrients, and oxygen) to differentiate sources of freshwater (meteoric water, sea-ice meltwater, and Pacific water) in the Arctic Ocean and study changes in their distribution over time; (2) the evolution of these tracers in response to on-going Arctic change (e.g., warming, loss of sea ice, increased biological activity); (3) the linkages between changes in the surface circulation of the Arctic Ocean and the flux and composition of freshwater exported through the Canadian Arctic Archipelago and Nares Strait; and (4) the use of autonomous platforms (Lagrangian floats and Seagliders) and biogeochemical sensors to study biogeochemical dynamics and net community production on relatively small (mesoscale and sub-mesoscale) spatial and temporal scales.

Curriculum Vitae

APL-Ocean Physics Projects

2008 North Atlantic Bloom

A vast renewal event happens each spring as a wave of tiny plant growth covers the North Atlantic Ocean. This mass greening of the ocean’s surface is observed dramatically from space by color-sensitive sensors on satellites as it extends from Bermuda to the ice edge in the Arctic during the season. The phytoplankton of the North Atlantic bloom play a major role in pulling CO2 from the atmosphere and storing it in the ocean. Despite the magnitude and importance of this event, it has rarely been observed from start to end due to the difficulty and expense of maintaining ships in the region for many months.

APL-UW investigators, their students, and colleagues from the University of Maine and Dalhousie University in Nova Scotia led an ambitious collaborative experiment in the North Atlantic near Iceland to coincide with the bloom in 2008. The challenge of the experiment was to characterized the bloom’s temporal and spatial evolutions of physics, biology, and chemistry over its entire duration.

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Selected Projects

  • Small Canadian Arctic River Flows (SCARFs)

    There are two primary goals of this project: (1) determine whether relatively small Canadian Arctic rivers significantly contribute to the total volume of freshwater that drains through Davis Strait and (2) determine if they are chemically distinct from larger North American rivers such as the Mackenzie and Yukon Rivers.  To achieve these goals we have collected water samples from eight different rivers across Nunavut and the Northwest Territories to determine their geochemical signatures (e.g., d18O, total alkalinity, barium, Sr isotopes, major ions, and dissolved organic carbon).  The first year (2014) of field work is completed and chemical analyses of river samples are ongoing.  The second (2015) and third (2016) years of the project will involve a continuation of the river sampling efforts as well as extending sampling into the adjoining estuaries to assess changes across the salinity gradient.

    Project page

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  • North Pole Environmental Observatory

    The observatory is staffed by an international research team that establishes a camp at the North Pole each spring to take the pulse of the Arctic Ocean and learn how the world’s northernmost sea helps regulate global climate.

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Selected Publications

  • Alkire, M.B., I. Polyakov, R. Rember, I.M. Ashik, V. Ivanov, and A.V. Pnyushkov (2017). Lower halocline water formation and modification, a comparison of physical and geochemical methods, manuscript in preparation.

  • Polyakov, I.V., A.V. Pnyushkov, M. Alkire, I.M. Ashik, T. Baumann, E.C. Carmack, I. Goszczko, J. Guthrie, V.V. Ivanov, T. Kanzow, R. Krishfield, R. Kwok, A. Sundfjord, J. Morison, R. Rember, and A. Yulin (2017). Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean, Science, doi:10.1126/science.aai8204.

  • Alkire, M. B., A. Jacobson, G. O. Lehn, R. W. Macdonald, and M. W. Rossi (2017). On the geochemical heterogeneity of rivers draining into the straits and channels of the Canadian Arctic Archipelago, Journal of Geophysical Research Biogeosciences, doi:10.1002/2016JG003723

  • Alkire, M.B., J. Morison, A. Schweiger, J. Zhang, M. Steele, C. Peralta-Ferriz, S. Dickinson (2017). A meteoric water budget for the Arctic Ocean, Journal of Geophysical Research, in review.

  • Alkire, M. B., A. D. Jacobson, G.O Lehn, and R.W. Macdonald (2015). Small rivers could have big impact on Arctic Ocean, Eos 96, doi:10.1029/2015EO034005.

  • Alkire, M.B., F. Nilsen, E. Falck, J. Søreide, and T. Gabrielsen (2015). Tracing sources of freshwater contributions to first-year sea ice in Svalbard fjords, Continental Shelf Research 101, 85-97.

  • Alkire, M.B., J. Morison, and R. Andersen (2015). Variability in the meteoric water, sea-ice melt, and Pacific water contributions to the central Arctic Ocean, 2000-2014, Journal of Geophysical Research 120, doi:10.1002/2014JC010023.

  • Alkire, M.B., E. D’Asaro, C. Lee, M.J. Perry, I. Cetinic, N. Briggs, and A. Gray (2014). Net community production and export from Seaglider measurements in the North Atlantic after the spring bloom bloom, Journal of Geophysical Research 119, doi:10.1002/2014JC010105.

  • Alkire, M.B., M.J. Perry, E. D’Asaro, and C. M. Lee (2013). Using sensor-based, geochemical measurements from autonomous platforms to estimate biological production and export of carbon during the 2008 North Atlantic spring bloom, Ocean Carbon and Biogeochemistry News 6(2), 1-6.

  • Morison, J., R. Kwok, C. Peralta-Ferriz, M. Alkire, I. Rigor, R. Andersen, and M. Steele, Changing Arctic Ocean Freshwater Pathways Measured With ICESat and GRACE, Nature, 481, 66-70, DOI: 10.1038/nature10705, 2012

  • Alkire, M.B., E. D’Asaro, C. Lee, M.J. Perry, A. Gray, I. Cetinic, N. Briggs, E. Rehm, E. Kallin, J. Kaiser, and A. Gonzalez-Posada (2012). Estimates of net community production and export using high-resolution, Lagrangian measurements of O2, NO3, and POC through the evolution of a spring diatom bloom in the North Atlantic, Deep-Sea Research I, 64: 157-174.

  • Alkire, M.B., K.K. Falkner, J. Morison, R.W. Collier, C.K.Guay, R.A. Desiderio, I.G. Rigor, M. McPhee (2010). Sensor-based profiles of the NO parameter in the central Arctic and southern Canada Basin: new insights regarding the cold halocline, Deep-Sea Research I 57: 1432-1443, 2010.

  • Alkire, M.B., K.K. Falkner, T. Boyd, R.W. Macdonald (2010), Sea-ice melt and meteoric water distributions in Baffin Bay and the Canadian Arctic archipelago, Journal of Marine Research 68(6), 767-798, 2010.

  • Alkire, M.B. (2010), Differentiating freshwater contributions and their variability to the surface and halocline layers of the Arctic and subarctic seas, Ph.D. Thesis, College of Oceanic & Atmospheric Sciences, Oregon State University, defended on March 19, 2010.

  • Abrahamsen, E.P., M.P. Meredith, K.K. Falkner, S. Torres-Valdes, M.J. Leng, M.B. Alkire, S. Bacon, I. Polyakov, V. Ivanov, S. Kirillov (2009). Tracer-derived freshwater budget of the Siberian Continental Shelf following the extreme Arctic summer of 2007, Geophysical Research Letters 36: doi:10.1029/2009GL037341.

  • McPhee, M., J. Morison, A. Proshutinsky, M. Steele, M. Alkire (2009), Rapid Change in Freshwater Content of the Arctic Ocean, Geophysical Research Letters 36: doi:10.1029/2009GL037525.

  • Alkire, M.B., K.K. Falkner, I. Rigor, M. Steele, J. Morison (2007). The return of Pacific waters to the upper layers of the central Arctic Ocean, Deep-Sea Research I 54: 1509-1529.

  • Alkire, M.B., J.H. Trefry (2006). Transport of spring floodwater from rivers under ice to the Alaskan Beaufort Sea, Journal of Geophysical Research 111: doi:10.1029/2005JC003446.

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