Observing the New Arctic

Physical oceanography Observational Seminar, Spring 2019

Professor Jen MacKinnon , Fridays 12-1, OAR / Keck 150

Course Overview

The Arctic Ocean is changing rapidly, as the ice melts, the water warms, and significant alterations in everything from mesoscale circulation to biogeochemistry follow suit. In this seminar we’ll investigate some of those changes through discussion of cutting edge observational papers.

Every week one or two students will lead discussion of one or two papers. All registered students will lead/present once, and should come other weeks having read the paper and prepared to contribute to the discussion.

Others (non-students at any level) are quite welcome to attend and join the discussion as well.

Schedule

• 4/5: Intro by Jen and full class discussion of (click on it) Carmak et al 15. Choose future topics and schedule

• 4/12: Channing, Tide-mediated warming of Arctic halocline by Atlantic heat fluxes over rough topography, Rippeth et al 15. [ Channing’s presentation]

• 4/19: Bobby, Is there a “new normal” climate in the Beaufort Sea?, Wood et al 13 [Presentation]

• 4/26: Margaret, Arctic Ocean basin liquid freshwater storage trend 1992–2012, Rabe et al 14 [Presentation]

• 5/3: Effie, The arctic ocean spices up, Timmermans and Jayne 16 [Presentation]

• 5/10: Alex, Seasonal and regional manifestation of Arctic sea ice loss, Onarheim et al 18 [Presentation]

• 5/17: Paul C An autonomous approach to observing the seasonal ice zone in the western Arctic (Lee et al) and Evolution of the eddy field in the Arctic Ocean's Canada Basin, 2005–2015 (Zhao et al 16) [Presentation]

• 5/24: Andre + Theresa. Seasonal to interannual variability of the Pacific water boundary current in the Beaufort Sea, Brugler et al (primary paper), and Characteristics and dynamics of wind-driven upwelling in the Alaskan Beaufort Sea based on six years of mooring data (secondary paper).

• 5/31: Emelia (bio-physical interactions). Are phytoplankton blooms occurring earlier in the Arctic? Kahru et al 2010. And secondary paper: Sea-ice algal phenology in a warmer Arctic, Tedesco et al May 2019 (!)

• 6/7: Emma, tbd

Additional Reference material (click on each one to go to the paper).

General warming rates and Sea ice reduction

• Cryosphere: Warmth from the deep, Carmak and Melling 2011

• Toward quantifying the increasing role of oceanic heat in sea ice loss in the new Arctic, Carmack et al 15

• **Consistent changes in the sea ice seasonal cycle in response to global warming, Eisenman et al 11

• Arctic amplification dominated by temperature feedbacks in contemporary climate models, Pithan and Mauritsen 14

• Arctic Ocean warming contributes to reduced polar ice cap, Polyakov et al 10

• Seasonal and regional manifestation of Arctic sea ice loss, Onarheim et al 18

• A decade of environmental change in the Pacific Arctic region, Wood et al 15

Freshwater balance

• Deterioration of perennial sea ice in the Beaufort Gyre from 2003 to 2012 and its impact on the oceanic freshwater cycle, krishfield et al 14

• Rapid change in freshwater content of the Arctic Ocean, McPhee et al 09

• Beaufort Gyre freshwater reservoir: State and variability from observations, Proshutinsky et al 09

Evolving Boundary Currents

• Shelfbreak circulation in the Alaskan Beaufort Sea: Mean structure and variability, Pickart 04

• The western Arctic boundary current at 152 W: Structure, variability, and transport, Nikolopoulos et al 09

• Two configurations of the western Arctic shelfbreak current in summer, von Appen and Pickart 12

• ** Warming of the interior Arctic Ocean linked to sea ice losses at the basin margins, Timmermans et al 18

Ocean/land interface, erosion, surf zone, cross-shore transport of freshwater, biogeochemistry, sediment, etc

• Modeling erosion of ice‐rich permafrost bluffs along the Alaskan Beaufort Sea coast, Barnhart et al 14a

• The effect of changing sea ice on the physical vulnerability of Arctic coasts., Barnhart et al 14b

Upper ocean boundary layer structure, turbulence, momentum, stresses

• ** The impact of stored solar heat on Arctic sea ice growth, Timmermans 15

• ** Episodic reversal of autumn ice advance caused by release of ocean heat in the Beaufort Sea, Smith et al 18

• Horizontal density structure and restratification of the Arctic Ocean surface layer, Timmermans et al 12

• Ekman veering, internal waves, and turbulence observed under Arctic sea ice, Cole et al 14

• Observations of upper ocean boundary layer dynamics in the marginal ice zone, Fer et al 07

• Mixing, heat fluxes and heat content evolution of the Arctic Ocean mixed layer, Sirevaag et al 11

• Seasonal and interannual variability of pan-Arctic surface mixed layer properties from 1979 to 2012 from hydrographic data, and the dominance of stratification for … Perralta-Ferriz and Woodgate 15

• Role of the upper ocean in the energy budget of Arctic sea ice during SHEBA, Shaw et al 09

• Influences of the ocean surface mixed layer and thermohaline stratification on Arctic Sea ice in the central Canada Basin, Toole et al 10

• A tale of two spicy seas, MacKinnon et al 16

Wind stress and surface waves (somewhat overlapping with above category)

• ** Swell and sea in the emerging Arctic Ocean, Thomson and Rogers 14

• Fixed-point observation of mixed layer evolution in the seasonally ice-free Chukchi Sea: Turbulent mixing due to gale winds and internal gravity waves, kawaguchi et al 15

• Seasonality and long‐term trend of Arctic Ocean surface stress in a model, Martin et al 14

• Ocean surface turbulence in newly formed marginal ice zones, Smith and Thomson 19

Pacific Water intrusions, Barrow Canyon, heat content, and heat content

• Increases in the Pacific inflow to the Arctic from 1990 to 2015, and insights into seasonal trends and driving mechanisms from year-round Bering Strait mooring data, Woodgate 18

• Pacific Ocean inflow: Influence on catastrophic reduction of sea ice cover in the Arctic Ocean, Shimada et al 06

• Observed increases in Bering Strait oceanic fluxes from the Pacific to the Arctic from 2001 to 2011 and their impacts on the Arctic Ocean water column, Woodgate et al 12

• Vertical heat transfer based on direct microstructure measurements in the ice-free Pacific-side Arctic Ocean: the role and impact of the Pacific water intrusion, kawaguchi et al 14

• Mechanisms of Pacific summer water variability in the Arctic's Central Canada Basin, Timmermans et al 14

• Water properties, heat and volume fluxes of Pacific water in Barrow Canyon during summer 2010, Itoh et al 15

• Microstructure Observations of Turbulent Heat Fluxes in a Warm-Core Canada Basin Eddy, Fine et al 18

Shelf and coastal

• Coupled wind-forced controls of the Bering–Chukchi shelf circulation and the Bering Strait throughflow: Ekman transport, continental shelf waves, and … Danielson et al 14

• Lateral mixing across ice meltwater fronts of the Chukchi Sea shelf, Lu et al 15

Internal Waves

• Internal waves in the Arctic Ocean: Comparison with lower-latitude observations, Levine et al 85

• Inertial currents in the Beaufort Sea: Observations of response to wind and shear, Merrifield and Pinkel 96

• Internal waves and velocity fine structure in the Arctic Ocean, D’Asaro and morehead 91

• Internal wave dissipation under sea ice, Morrison et al 85

• Internal waves and mixing in the Arctic Ocean, D’asaro and Morrison 92

• Revisiting internal waves and mixing in the Arctic Ocean, Guthrie et al 13

• Observations of internal wave generation in the seasonally ice‐free Arctic, Rainville and Woodgate 09

• ** Near-inertial internal wave field in the Canada Basin from ice-tethered profilers, Dosser et al 14

• Internal waves and mixing in the marginal ice zone near the Yermak Plateau, Fer et al 10

• ** Wind‐driven mixing at intermediate depths in an ice‐free Arctic Ocean, Lincoln et al 16

• Near-inertial internal waves and sea ice in the Beaufort Sea, Martini et al 14

• The wavenumber–frequency spectrum of vortical and internal-wave shear in the western Arctic Ocean, Pinkel 08

• Near-inertial wave propagation in the western Arctic, Pinkel 05

General mixing

• ** Tide-mediated warming of Arctic halocline by Atlantic heat fluxes over rough topography, Rippeth et al 15

• Mixing across the Arctic Ocean: Microstructure observations during the Beringia 2005 expedition, Rainville and Winsor 08

• Impact of wind-driven mixing in the Arctic Ocean, Rainville et al 11

• Observations of turbulent mixing and hydrography in the marginal ice zone of the Barents Sea, Sundfjord et al 07

• Intermittent intense turbulent mixing under ice in the Laptev Sea continental shelf, Lenn et al 11

• Vertical mixing at intermediate depths in the Arctic boundary current, Lenn et al 09

• Vertical diffusivity of the Western Arctic Ocean halocline, Shaw and STanton 14

• Internal wave mixing in the Baltic Sea: Near‐inertial waves in the absence of tides, Van der Lee and Umlauf 11

Changing T-S structure: spice, double-diffusion, and ‘Altantification’

• Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean, polyakov et al 17

• ** Observed Atlantification of the Barents Sea causes the polar front to limit the expansion of winter sea ice, Barton et al 17

• ** Arctic warming hotspot in the northern Barents Sea linked to declining sea-ice import, Lind et al 18

• ** The arctic ocean spices up, Timmermans and Jayne 16

Physics and Biology intersection (all could be **)

• Are phytoplankton blooms occurring earlier in the Arctic?, Kahru et al 11

• Bio‐optical feedbacks among phytoplankton, upper ocean physics and sea‐ice in a global model, Manizza et al 05

• Amplified Arctic warming by phytoplankton under greenhouse warming, Park et al 15

• Impacts of chromophoric dissolved organic material on surface ocean heating in the Chukchi Sea, Hill 08

• Increased intrusion of warming Atlantic water leads to rapid expansion of temperate phytoplankton in the Arctic, Neukermans and Babin 18