Aquatic vegetation provides ecosystem services of great value. Its protection and restoration has become a major focus in coastal management. We seek to better understand the role of vegetation in protecting shorelines from wave energy. The motion of flexible vegetation blades can significantly reduce the drag force, which will in turn affect the wave decay. The wave decay can be characterized using an effective blade length, 𝑙𝑒, which represents the length of a rigid blade that generates the same wave damping as a flexible blade with length 𝑙. Previous studies suggest that the effective blade length ratio 𝑙𝑒/𝑙~(𝐶𝑎𝑤𝐿)^−1/4, in which Cauchy number 𝐶𝑎𝑤 defines the ratio of hydrodynamic drag to blade stiffness and the normalized blade length L is the ratio of blade length to wave orbital excursion. This laboratory research extends the existing studies and the aim of finding the link between drag force on an individual blade and wave dissipation over a meadow. Flume experiments were conducted to measure the wave decay over an artificial meadow constructed from plastic blades and wooden dowels. Another set of experiments were conducted to measure the drag force on the individual blades. It’s observed that the scaling law (force on individual blade) is able to predict the wave decay over the meadow. A correction factor was needed to account for the fact that the individual blades within the meadow shelter one another. As the stem density increases, the sheltering becomes more significant, resulting in a reduced rate of wave energy dissipation.

As part of the Norwegian SI-ARCTIC Program, in late summer of 2014 and 2015 acoustic data (18, 38 and 120 kHz) for the estimation of the distribution and abundance of zooplankton and fish were collected from regions west and north of Svalbard, to examine high latitude epipelagic and mesopelagic scattering structures. The deep scattering layer biological constituents were determined from vertical and oblique hauls with zooplankton nets and pelagic trawls. There was strong patchy scattering in the upper part of the epipelagic zone (<50 m) throughout the area due to 0-group fish that were particularly abundant west of the Spitsbergen Archipelago and by copepods, krill, and amphipods. The distinct Off-shelf deep scattering layer (DSL) occurred between 200 and 600 m and contained a range of larger longer lived organisms (mesopelagic fish and macrozooplankton). In eastern Fram Strait, the DSL also included larger fish close to the shelf/slope break that were associated with Warm Atlantic Water moving north towards the Arctic Ocean, but switched to dominance by species having weaker scattering signatures further offshore. The Weighted Mean Depths of the DSL were deeper (WMD >440 m) in the Arctic habitat north of Svalbard compared to those south in the Fram Strait west of Svalbard (WMD ~400 m) and the mesopelagic nautical area scattering coefficient was a factor of approximately 6-10 lower around Svalbard compared to the areas in the south-eastern part of the Norwegian Sea ~62º30’N. The DSL displayed a clear ascending and descending diel movement. The high-light WMD with respect to backscattered energy was statistically deeper than the low-light WMD for the locations studied. This behavior of the DSL was consistent both when the sun was continuously above the horizon and after it started to set on 1 September, and both in open water and sea ice covered waters.

The marginal sea ice zone (MIZ) is a complex interface between the open ocean and the pack ice, where ocean-ice-atmosphere interactions are extremely complex. With a width of about 100 km, similar to the grid size of many climate models, the MIZ is not resolved in CMIP5 climate scenarios. In recent years, coupled climate models have been developed with ocean components at higher resolution, such as the high resolution version of the Met Office Global Coupled Model GC3 based on the GO6 configuration of the ORCA12 1/12° ocean model. We compare the MIZ representation in a coupled simulation with a simulation using the same ocean component forced by observed atmospheric data. Biases in the MIZ position and width are of the same order of magnitude in the coupled and forced model. The sea ice edge is strongly influenced by the ocean circulation and is often found at the wrong location, even when an observed atmospheric state is used to force the model. Despite a possible mismatch between atmosphere and ice/ocean in the forced model, due to the absence of feedback between sea ice and atmospheric temperature, surface heat fluxes in the MIZ are similar in amplitude in the coupled and forced simulations.  Our analysis focuses on the Greenland Sea because it is region of deep water formation, a major control of the Atlantic Meridional Overturning Circulation and thus very important for climate scenarios. The strong interannual variability of sea ice in the Greenland Sea is examplified by the Odden tongue, a protrusion of sea ice extending northeastward away from the Greenland continental slope. The coupled model exhibits such interannual variability, with a sea ice concentration larger than observed on average. The relationship between atmosphere, ice concentration and mixed layer depth is analyzed to assess the performance of both coupled and forced 1/12° models to represent deep water formation in the Nordic seas.

When rain falls over the ocean, it produces a vertical salinity profile that is fresher at the surface. This fresh water will be mixed downward by turbulent diffusion through gravity waves and the wind stress, which dissipates over a few hours until the upper layer (1-5 m depth) becomes well mixed. Therefore, there will be a transient bias between the bulk salinity, measured by in-situ instruments, and the satellite-measured SSS (representative of the first cm of the ocean depth). Based on observations of Aquarius (AQ) SSS under rain conditions, a rain impact model (RIM) was developed to estimate the change in SSS due to the accumulation of precipitation previous to the time of the satellite observation. RIM uses ocean surface salinities, from the HYCOM (Hybrid Coordinate Ocean Model) and the NOAA global rainfall product CMORPH, to model transient changes in the near-surface salinity profile. Also, the RIM analysis has been applied to SMOS (Soil Moisture and Ocean Salinity) and SMAP (Soil Moisture Active Passive), with similar results observed. The original version of RIM assumes a constant vertical diffusivity and neglects the effects of wind and wave mixing. However, it has been shown that the persistence of rain-induced salinity gradients depends on wind speed, with freshening due to rain during weak winds (less than 2 m/s) persisting for 8 hours or more. Moreover, the mechanical mixing of the ocean caused by wind and waves rapidly reduces the salinity stratification caused by rain. Also, previous results using RIM, in the presence of moderate/high wind speeds, show that the model overestimates the effect of rain on the SSS, which suggests that for RIM to accurately model the near-surface salinity stratification, the effect of wind needs to be included in the model. To address this issue, this paper will focus on an improved RIM-2 that parameterizes the effects of wind on the vertical diffusivity (Kz). Results will be presented that compare RIM and RIM-2 calculations at different depths for several Kz parametrizations. Also, comparisons, between RIM-2 at depths of several meters with measurements from in-situ salinity instruments, will be presented.

Stanford University offers a wide variety of opportunities for its students to engage in substantive, meaningful academic and professional experiences at the interface of ocean science and policy. As a student studying interdisciplinary environmental science, these programs have been transformative for how I see myself academically and professionally. The opportunities are made possible by collaborations with other academic institutions, non-governmental organizations, and governments. For instance, the Stanford at SEA program partners with the Sea Education Association to introduce students to marine biology and oceanography alongside sail handling and celestial navigation aboard a tall ship. While dissecting fish stomachs on the ship, I became more comfortable identifying myself as a scientist and fell in love with being at sea. Outside of courses, Stanford provides students with myriad ways to undertake significant work experiences. The Stanford in Washington program, for example, matches undergraduates with government offices or nonprofit organizations in Washington, D.C., for full-time internships during the school year. Students also take classes in the evening to complement their work experiences. I interned at the Department of Justice in the Environment and Natural Resources Division, which gave me a unique perspective on how federal agencies enforce environmental statutes. The Haas Center for Public Service and Stanford in Government, a student organization, also provide stipends for hundreds of summer fellowships. With SIG funding, I worked at the Center for Ocean Solutions and contributed significantly to a coastal adaptation policy project and planning for a new small-scale fisheries initiative. My experience with Stanford's programs have allowed me to substantively contribute to my learning about the ocean and to the missions of my host organizations while also giving me a sense of direction for my plans post-graduation.

This paper compares and contrasts UAS-based Structure from Motion (SfM) and TLS survey methods as applied to evaluate the impacts of, and recovery from, the extreme El Niño 2015-16 on the seasonal geomorphic and sediment budget responses of an embayed, high-energy beach-dune system on the central coast of British Columbia, Canada. TLS and UAS mapping campaigns over a two-year period provided seasonal bare-earth digital terrain models (DTMs) and orthophoto mosaics. Spatial-temporal change detection methods were used to quantify volumes of significant erosion and deposition within the beach-dune system. The frequency and magnitude of erosive events and aeolian activity were also estimated from oblique, time-lapse photography. During the 2015-16 El Niño season, elevated water levels and storm waves eroded the foredune and lowered the beach surface by ~ 1m. Erosion was greatest in the middle of the beach with dune scarping of over 2m where wave energy was focused. Minor accretion occurred during the summer of 2016 on the upper beach, and ramp rebuilding was observed mostly from slumping and avalanching of existing dune sands. The following winter 2017 storm season led to minor erosion on the beach and extensive incipient dune development and sand ramp recovery fronting the foredune to an extent close to pre-El Niño elevations. Comparison of change surfaces between methods revealed limitations in the SfM method, namely due to vegetation effects on DTM generation, which limit its ability to detect change in the coastal environment. The costs, time, logistics, and accuracy for both SfM and TLS survey methodologies for coastal geomorphic change detection analysis is also evaluated. Combined, the UAS and SfM workflow provides a competitive solution to more expensive and time-consuming survey methods, such as TLS and aerial LiDAR, but its utility and accuracy is highly dependent on research objectives and post-processing techniques.

We examine the role of transient and standing eddies in an idealized model with a Southern Ocean analog and two basins in the Southern hemisphere. We use the new MOM6 code base in an entirely adiabatic configuration, which allows for full equilibrium integration in only 100 years of simulation time. Fine resolution eddy-resolving simulations at 1/16- and 1/8-degree resolutions are performed in cases with and without continental barriers and/or bottom roughness. A time- and zonal-Reynolds averaging approach is used to decompose eddy fluxes into transient eddies and standing meanders. For a flat bottom channel the wind driven overturning circulation is balanced by transient eddies, consistent with previous studies. However, when continental barriers or bottom roughness are present, we find that standing meanders are dominant in the Southern Ocean.

The interior of lakes is often quiescent and most of the mixing in a lake occurs at the sloping boundaries, where wind-induced internal waves create turbulence (which leads to mixing) through interactions with the lakebed. To predict the occurrence and strength of turbulence in terms of meteorological forcing and stratification, we investigated the dependence of internal wave type, and their contribution to turbulence on the slope, on the Lake number, which compares the stabilizing tendency of stratification to the destabilizing tendency of the wind. Three thermistor chains and a meteorological station were deployed in West Okoboji Lake (length ~ 9 km, max. depth ~ 40 m) for two weeks. A wavelet analysis was conducted to determine time periods when different wave frequencies were excited, with particular focus on the first vertical mode seiche, the critical frequency with respect to the stratification and slope, and high frequency waves in the band of 1-10 times the buoyancy frequency. We measured the velocities in the bottom boundary layer (BBL) with a high resolution acoustic current profiler (2 MHz Nortek HR Aquadopp) and then computed the turbulent dissipation rate using the structure function method, which uses the spatial correlations of velocity along a beam to estimate the dissipation. This generated a two week time series of turbulent dissipation rate in the BBL which was then compared to the wavelet amplitudes. During the deployment, a strong daily wind forced near constant internal wave activity. The theoretical period of the first vertical mode seiche was ~17 hours, but the diurnal wind forcing interfered with free oscillation of this mode. Although not an obvious natural frequency of the lake, waves of the critical frequency (which had a period of ~11 hours) were activated throughout the measurement period. High-frequency waves were observed in the thermistor chain near the slope at the lowest Lake number wind events. The turbulence observed on the boundary was highest during these events, implying that the low frequency seiching was less important than higher frequency motions in driving turbulence on the slope.

The Puget Sound is a complex estuarine system within the Salish Sea, fed by both high salinity water from the Pacific Ocean and freshwater from a number of rivers. The Snohomish River is one of the largest of these freshwater inputs, transporting freshwater from the Skykomish and Snoqualmie rivers to Port Gardner Bay off the coast of Everett. At its mouth, the higher density salt water from the Puget Sound intrudes into the freshwater, forming a salt wedge that causes a highly stratified water column which rapidly changes with the tidal cycle. In this stratified water column, little mixing occurs between the different layers of the water, resulting in a lack of nutrients near the surface. This study aims to quantify the amount of mixing occurring at this location in relation to tidal patterns and season and analyze the effect varying levels of mixing have on related chemical properties. This research is being conducted at the Ocean Research College Academy (ORCA), a dual enrollment program through Everett Community College. In cooperation with Gravity Marine Consulting and the Port of Everett, ORCA has permanently moored a SeaBird CTD 3 meters below the surface in the mouth of the Snohomish River. The CTD captures temperature, salinity, chlorophyll, turbidity, and dissolved oxygen measurements at 30-minute intervals. Velocities in 3-dimensions are recorded by a Nortek Aquadopp. This study will define the characteristics of the salt wedge in relation to temperature and salinity and then look at its influence on chlorophyll and turbidity levels.

Ocean General Circulation Models (OCGM) have been used for ocean forecasts and reanalysis in the past; successfully reproducing realistic large scale features such as Western Boundary Currents (WBC) which evolve slowly in time. Recent developments of three dimensional OCGM’s include the incorporation of tidal forcing embedded in the numerical integration. With the inclusion of higher frequency tidal forcing it is now possible to study the impact of tides on the larger scale features of the ocean reproduced in the OCGM’s such as WBC’s through comparison of simulations with and without tides. We compare two 1/12.5° simulations of the Hybrid Coordinate Ocean Model (HYCOM) and report on differences in the mean position, transports, and warm/cold core eddy production in the Gulf Stream and Kuroshio Current and their extensions across the Atlantic and Pacific Oceans.

Chukchi Sea benthic ostracode assemblages collected during a research cruise aboard the USCGC Healy in 2017 are compared to collections from past years, primarily 2009 and 2010, with a goal of understanding recent species changes related to temperature, total organic carbon (TOC) and sediment grain size. The study area includes the continental shelf region influenced by the Alaska Coastal Current and the northward extension of the Bering Sea Shelf waters that flow through Bering Strait. Significant temporal (decadal, interannual) and spatial variability in the proportions of dominant species in the assemblage were observed, including an increase in subarctic species, particularly, Normanicythere leioderma, which is typically dominant in the Bering Sea, but which showed a notable range expansion in 2017 into the Chukchi Sea (20% of the 2017 Chukchi Sea assemblage). Secondary subarctic species with increasing abundance include Schizocythere ikeyai (8%) and Munseyella kiklukhensis (7%). A corresponding decline in dominance of Paracyprideis pseudopunctillata (4%), a common Arctic species in Chukchi, Beaufort and Laptev Sea assemblages, is another significant change. Continued monitoring of temperature-sensitive ostracode species in the Bering and Chukchi Seas is planned to provide additional information on annual and decadal variability in species dominance.

Using bibliometric analysis techniques, we trace the evolution of climate and climate-change related articles in major oceanographic journals, 1987-2017. We use these bibliometric tools (network mapping, cluster analysis, alluvial analysis, corpus keyword detection) to document trends in growth, integration and centralization of climate-related research within ocean sciences over the past three decades. Such analysis methods offer an objective and complementary methodology, in contrast to the traditional “expert panel” approach, for guiding long-term strategic science planning. But how does the macro trend compare to scientific outputs supported by large ocean observatory facilities? Have scientists making use of these facilities followed, led or diverged from the general trend? We compare the macro trend to corpora of published science from two such facilities, Australia’s Integrated Marine Observing System (IMOS) and Ocean Networks Canada (ONC). The goal is to discern the extent to which these “big science” ocean observatories have been able to support or lead research that helps inform policy, management and the public about critical societal issues such as long term ocean change.

Researchers are challenged with preparing and complying with data management plans and open data mandates. The ocean science repository community has demonstrated the benefits of providing FAIR (findable, accessible, interoperable, and reusable) data to its researchers through innovative alliances, robust metadata, and semantic connectivity. Challenges still exist in coordinating science policy, and research services across funders, institutions, and publishers that support the researcher’s data management needs. The convenors of this session request abstracts that focus on the value of FAIR data to the research community and the tools that support data discovery, compliance with data management plans, transparency, reproducibility, and research integrity.

Airborne lidar surveys were used to characterize subsurface layers of phytoplankton in the Arctic Ocean during the latter half of July 2014 and again during the latter half of July 2017. The survey region included US waters in the Beaufort and Chukchi Seas. In 2014, layers were detected in open water and also in openings in pack ice where up to 90% of the surface was covered by ice. The layers in the pack ice were less prevalent, weaker, and shallower than those in open water. Layers were more prevalent in the Chukchi Sea than in the Beaufort Sea. Three quarters of the layers observed were thinner than 5 m. In 2017, ice conditions were significantly different. The ice edge was farther north at the beginning of the measurement period in 2017 and retreated faster during that period. As a result, flights were conducted in the areas surveyed in 2014 in addition to areas near the ice edge. Data analysis of the 2017 flights will be done in the same way as the 2014 data. Low clouds and fog are common in the Arctic. The lidar can operate through optically thin clouds and fog, but at some point, the beam is completely attenuated. Data where the atmospheric attenuation is too great must be removed from consideration by visual inspection. Detection of ice in the lidar return is straightforward, since ice produces a saturated return in the lidar receiver. Subsurface layers will be identified by visual inspection of the data, and the characteristics will be calculated. Subsurface layers are clearly present in the data, and their characteristics will be presented, along with a comparison between 2014 and 2017 results.