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Roger Andersen Principal Mathematician roger@apl.washington.edu Phone 206-543-1258 |
Biosketch
Roger Andersen has made 35 trips to the polar regions for scientific research since joining the Polar Science Center in 1975, when it was the Arctic Ice Dynamics Joint Experiment. His current projects include the North Pole Environmental Observatory and the Freshwater Switchyard of the Arctic Ocean.
Education
B.A. Mathematics, Washington State University, 1970
M.S. Atmospheric Science, University of Washington, 1973
Roger Andersen's Website
http://psc.apl.washington.edu/wordpress/people/research-staff/roger-andersen/ |
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Videos
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Changing Freshwater Pathways in the Arctic Ocean Freshening in the Canada Basin of the Arctic Ocean began in the 1990s. Polar scientist Jamie Morison and colleagues report new insights on the freshening based in part on Arctic-wide views from two satellite system. |
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5 Jan 2012
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The Arctic Ocean is a repository for a tremendous amount of river runoff, especially from several huge Russian rivers. During the spring of 2008, APL-UW oceanographers on a hydrographic survey in the Arctic detected major shifts in the amount and distribution of fresh water. The Canada basin had freshened, but had the entire Arctic Ocean? |
Publications |
2000-present and while at APL-UW |
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Arctic iceocean coupling and gyre equilibration observed with remote sensing Dewey, S., J. Morison, R. Kwok, S. Dickinson, D. Morison, and R. Andersen, "Arctic iceocean coupling and gyre equilibration observed with remote sensing," Geophys. Res. Lett., 45, 1499-1508, doi:10.1002/2017GL076229, 2018. |
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16 Feb 2018 ![]() |
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Model and observational evidence has shown that ocean current speeds in the Beaufort Gyre have increased and recently stabilized. Because these currents rival ice drift speeds, we examine the potential for the Beaufort Gyre's shift from a system in which the wind drives the ice and the ice drives a passive ocean to one in which the ocean often, in the absence of high winds, drives the ice. The resultant stress exerted on the ocean by the ice and the resultant Ekman pumping are reversed, without any change in average wind stress curl. Through these curl reversals, the ice‐ocean stress provides a key feedback in Beaufort Gyre stabilization. This manuscript constitutes one of the first observational studies of ice‐ocean stress inclusive of geostrophic ocean currents, by making use of recently available remote sensing data. |
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Variability in the meteoric water, sea-ice melt, and Pacific water contributions to the central Arctic Ocean, 20002014 Alkire, M.B., J. Morison, and R. Andersen, "Variability in the meteoric water, sea-ice melt, and Pacific water contributions to the central Arctic Ocean, 20002014," J. Geophys. Res., 120, 1573-1598, doi:10.1002/2014JC010023, 2015. |
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12 Mar 2015 ![]() |
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Fourteen years (20002014) of bottle chemistry data collected during the North Pole Environmental Observatory were compiled to examine variations in the composition of freshwater (meteoric water, net sea-ice meltwater, and Pacific water) over mixed layer of the Central Arctic Ocean. In addition to significant spatial and interannual variability, there was a general decrease in meteoric water (MW) fractions at the majority of stations reoccupied over the duration of the program that was approximately balanced by a concomitant increase in freshwater from sea-ice melt (SIM FW) between 2000 and 2012. Inventories (0120 m) of MW and SIM FW computed using available data between 2005 and 2012 exhibited similar variations over the study area, allowing for first-order estimates of the mean annual changes in MW (389±194 km3 yr-1) and SIM FW (292±97 km3 yr-1) for the Central Arctic region. These mean annual changes were attributed to the diversion of Siberian river runoff to the Beaufort Gyre and the overall reduction of sea ice volume across the Arctic, respectively. In addition to this lower-frequency variability, spatial gradients and interannual variations in MW, SIM FW, and Pacific water contributions to specific locations were attributed to shifts in the Transpolar Drift that advects waters of eastern and western Arctic origin through the study area. |
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Changing Arctic Ocean freshwater pathways Morison, J., R. Kwok, C. Peralta-Ferriz, M. Alkire, I. Rigor, R. Andersen, and M. Steele, "Changing Arctic Ocean freshwater pathways," Nature, 481, 66-70, doi:10.1038/nature10705, 2012. |
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5 Jan 2012 ![]() |
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Freshening in the Canada basin of the Arctic Ocean began in the 1990s and continued to at least the end of 2008. By then, the Arctic Ocean might have gained four times as much fresh water as comprised the Great Salinity Anomaly of the 1970s, raising the spectre of slowing global ocean circulation. Freshening has been attributed to increased sea ice melting and contributions from runoff, but a leading explanation has been a strengthening of the Beaufort High a characteristic peak in sea level atmospheric pressure which tends to accelerate an anticyclonic (clockwise) wind pattern causing convergence of fresh surface water. Limited observations have made this explanation difficult to verify, and observations of increasing freshwater content under a weakened Beaufort High suggest that other factors must be affecting freshwater content. |
In The News
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Coast Guard assists Arctic Ocean research Anchorage Daily News, Marc Lester A Coast Guard C-130 flew from Anchorage over the Arctic Ocean on Tuesday, October 12, 2010, on a mission to deploy a research bouy. The Coast Guard, the University of Washington and the National Ice Center partnered on the project to gather information on changing conditions in the Arctic. |
14 Oct 2010
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