Arctic coastlines, and in particular the northern coast of Alaska, are eroding at rates of meters per year. Coastal flooding events are becoming more common, as reductions in seasonal sea ice create large fetches for autumn storms. The proposed work concerns the oceanographic factors associated with coastal erosion and flooding, which are distinct from the geologic controls. Key among these oceanographic factors is the previously demonstrated increasing trend in surface wave activity throughout the western Arctic.

Field observations will be collected and a coupled modeling system will be developed that together quantify the wave-ice-ocean interactions along the northern coast of Alaska. This new model will be applied, after calibration and validation with the field observations, to generate a 20-year hindcast. The hindcast will be used to investigate the climate signals in Arctic wave–ice–ocean coupling. The results will determine:

• The significance of coastal protection via scattering and dissipation of waves by sea ice
• The thermodynamic and mechanical effects of increasing wave energy
• The changes in coastal flooding and circulation associated with increasing wave momentum

Cruise dates, activities, and stations:

• 6 Nov: Mobilize in Nome, AK
• 7 Nov: Depart, transit north
• 8 Nov: Transit North
• 9 Nov: Deploy mooring line and sampling at Icy Cape (CODA Site 1)
• 10 Nov: Recover/redeploy U Delaware / ONR acoustics mooring
• 11 Nov: GOWEST Fishing in open water
• 12 Nov: Moorings, Stations, and SWIFTs at Jones Islands (CODA Site 2)
• 13 Nov: Moorings, Stations at Flaxman Island (CODA Site 3)
• 14 Nov: GOWEST fishing at the eastern shelfbreak
• 15 Nov: GOWEST fishing in the eastern basin and the mid-slope
• 16 Nov: Stations and redeploy at Jones Is (CODA Site 2)
• 17 Nov: GOWEST fishing at the mid shelf break (with full ice station)
• 18 Nov: GOWEST fishing in the mid basin (and transits West)
• 19 Nov: GOWEST fishing at the western basin (and transits West)
• 20 Nov: GOWEST fishing at the western shelf (and transits South)
• 21–23 Nov: SWIFT buoys and stations at Icy Cape (CODA S1)
• 24 Nov: Turnaround moorings at Icy Cape (CODA S1)
• 25–26 Nov: Transit south *
• 27 Nov: Personnel transfer in Nome
• 28 Nov: Transit south
• 29–30 Nov: Transit south, with pause for SWIFT buoy testing in open water
• 1 Dec: Arrive Dutch Harbor, AK, begin demobilization

* The return transit began early to account for an adverse weather forecast. This amounts to two days of lost science operations from the CODA project.

December 1: R/V Sikuliaq arrived Dutch Harbor in the morning.

Demobilization. CODA project completed.

November 28–30: Transit South, with pause for SWIFT buoy testing in open water.

There was an extensive field of pancake ice upon arrival near the shore of Icy Cape. Conditions were ideal to monitor interaction of an incoming storm and this new shore ice — 30 knot winds, 3 m (10 ft) seas from the N/NE. Sampling based on moorings placed earlier in the trip in a perpendicular line from the coast at 3, 6, 9, and 12 miles from shore, encompassed myriad ocean conditions from thick pancake ice to open water.

At each station, SASSY (Sediment and Salinity System) was sent through water column a few times. Bottom sediment samples collected and surface ice samples collected.

24-hr/day data collection: Three CODA watch teams, 8-hr shifts per team. SWIFT buoys were deployed and drifted toward coast with the onshore wind. Once their satellite antennas were fully iced (preventing signals to ship), they were recovered, de-iced, and redeployed. Significant amount of data successfully collected.

November 23–24: Steady snow and windy conditions for the past 3 days.

At S1 (Icy Cape), data was gathered during and after a wind event. All three moorings and the 'sea spider' were retrieved and redeployed. This will augment the data and samples gathered from over 100 stations in the same area.

November 20, Weather Changes Expected: Weather has been mild over the western arctic this week — winds less than 15 knots and very little wave activity. But, today a significant low pressure system is developing to the south.

Tonight, the R/V Sikuliaq will leave the protection of sea ice and head toward Icy Cape (site 1), to a more coastal area as the storm rolls by. The intended vantage point is near the site of the initial mooring deployment. The science team will observe the storm event three ways: through direct observation, castings off the ship (with the CTD, LISST, and SASSY)*, and anchored moorings.

The storm should peak tomorrow, November 21st, bringing 3–4 m (9–12 ft) waves.

* (respectively: Conductivity–Temperature–Depth, Laser In-Situ Scattering and Transmissiometry, Sediment and Salinity System)

– – – – –

5:35 PM Update: Ship is motoring southwest, about 70 miles west of Barrow, in open water. The wind is still light with a gentle swell.

November 11–17, North of Prudhoe Bay in the Beaufort Sea: The science team successfully deployed three additional pressure logger moorings — to measure and record pressure and temperature at varying depths form the sea floor — at a new site located west of the six moorings deployed at two other sites last August. Each site has three moorings, placed 3 miles apart.

The ship transited east to the middle site to retrieve August moorings. All three moorings were successfully retrieved, although the third one did not respond to the acoustic release 'ping' and was manually trawled and caught.

The ship then moved to the last site on an overnight transit eastward encountering thicker than anticipated ice. Progress was slowed to half the expected speed (from 6 knots to 3 knots) and arrived at the first mooring location much later than scheduled. Sikuliaq's thrusters were used to break away ice in order to see the buoy if it surfaced. Retrieval was a lengthy process, requiring much ship maneuvering and crew muscle to clear the ice around the small buoy. Mooring was retrieved. At the second mooring sea conditions were much better, but the acoustic call to release its buoy went 'unconfirmed.' Ship was repositioned for another attempt — still no release. Due to limited daylight, the decision was made to continue retrieval attempt of second mooring and abort retrieval attempt of the third and final mooring at this site. Despite continued efforts, second mooring was not recovered.

November 10: After two days' transit time from Nome, the science team deployed the first set of moorings near Icy Cape in the Chukchi Sea. The first mooring, a sea floor tripod, was deployed using the ship's A-frame in 30 m of water 12 nautical miles from shore. The next three moorings were placed along a line at 9, 6, and 3 nautical miles from shore. These are simple anchors with pressure loggers and sub-surface thermistor chains that could be deployed by hand.

These four moorings, along with eight more to be deployed in the coming weeks, will record wave properties, water turbulence, temperature, and current data autonomously. They will rest on the seafloor through the fall freeze up, under the winter ice, and through the summer melt, before being retrieved next September.

While on these sites, the team also collected sediment, water samples, and CTD data. All of the deployments went well, aided by settled weather conditions and strong coordination with the ship's crew.

November 7: The fully loaded R/V Sikuliaq departed Nome, motoring north at about 10 knots in winds of 35 knots.

November 5: 'SIKULIAQ HEADS NORTH: STORMS, ICE, AND THE FOOD CHAIN' — a joint community presentation by three of the lead scientists for the Strait Science Series, hosted at Nome’s University of Alaska Northwestern campus. Dr. Jim Thomson talked about his focus on understanding wave mechanics and how storm waves affect ice formation and durability along the shore. Dr. Hauke Flores discussed the algae under the ice and the society of creatures it supports. And Dr. Franz Mueter talked about the small but critical Arctic cod populations that depend on that layer of algae.

Early November: R/V Sikuliaq cruised northwest from Newport, Oregon across the Gulf Alaska, then north through the Bering Sea to Nome, Alaska.

Early August: The research team worked for several days out of Prudhoe Bay in the R/V Ukpik to deploy seafloor instruments to measure waves and temperatures throughout the open-water summer and into the autumn ice advance. The goal is to observe coastal conditions with and without ice, to understand how the ice protects the coasts from waves.