Hydrographic shipboard profile data collected within Olympic coast national marine sanctuary, 2005-2023.

Olympic Coast National Marine Sanctuary (OCNMS), which was established in 1994 and covers an area of 8257 km2, is located along Washington State's remote and rugged outer coast towards the northernmost extent of the California Current System (CCS). In this region, summertime equatorward winds drive seasonal upwelling of cold, nutrient rich waters onto the continental shelf. These waters help fuel a highly diverse and productive ecosystem that includes marine mammal and seabird communities as well as commercially and culturally important fisheries. The sanctuary is located within the boundaries of the legally defined Usual and Accustomed (U&A) fishing grounds of four Coastal Treaty Tribes, the Hoh Tribe, Makah Tribe, Quileute Tribe, and the Quinault Indian Nation, which hold treaty fishing rights and co-manage fisheries and other natural resources within the sanctuary through state, federal, and international partnerships and agreements. This data article describes shipboard hydrographic Conductivity-Temperature-Depth (CTD) and dissolved oxygen profile data that were collected within the sanctuary at fourteen locations during mooring deployment, recovery, and maintenance cruises between the months of May and October from 2005-2023. The 792 CTD profiles were acquired using Sea-Bird Scientific 19 SeaCAT or 19plus SeaCAT CTD profilers with associated SBE-43 (Sea-Bird Electronics) or Beckman or YSI-type (Yellow Springs Instruments) dissolved oxygen sensors. The data were processed using Sea-Bird Scientific's SBE Data Processing application. These data are needed for improving our understanding of subsurface oceanographic conditions - including marine heat waves, changes in timing of spring transition to upwelling, seasonal hypoxia, and ocean acidification - in this important but undersampled region, and can be used to help improve the management of marine resources regionally and within the sanctuary. The CTD cast data are available via Zenodo at https://doi.org/10.5281/zenodo.10466124.

Exchange of Plankton, Pollutants, and Particles Across the Nearshore Region.

Exchange of material across the nearshore region, extending from the shoreline to a few kilometers offshore, determines the concentrations of pathogens and nutrients near the coast and the transport of larvae, whose cross-shore positions influence dispersal and recruitment. Here, we describe a framework for estimating the relative importance of cross-shore exchange mechanisms, including winds, Stokes drift, rip currents, internal waves, and diurnal heating and cooling. For each mechanism, we define an exchange velocity as a function of environmental conditions. The exchange velocity applies for organisms that keep a particular depth due to swimming or buoyancy. A related exchange diffusivity quantifies horizontal spreading of particles without enough vertical swimming speed or buoyancy to counteract turbulent velocities. This framework provides a way to determinewhich processes are important for cross-shore exchange for a particular study site, time period, and particle behavior.

A stitch in time: Combining more than two decades of mooring data from the central Oregon shelf.

The highly biologically productive northern California Current, which includes the Oregon continental shelf, is an archetypal eastern boundary region with summertime upwelling driven by prevailing equatorward winds and wintertime downwelling driven by prevailing poleward winds. Between 1960 and 1990, monitoring programs and process studies conducted off the central Oregon coast advanced the understanding of many oceanographic processes, including coastal trapped waves, seasonal upwelling and downwelling in eastern boundary upwelling systems, and seasonal variability of coastal currents. Starting in 1997, the U.S. Global Ocean Ecosystems Dynamics - Long Term Observational Program (GLOBEC-LTOP) continued those monitoring and process study efforts by conducting routine CTD (Conductivity, Temperature, and Depth) and biological sampling survey cruises along the Newport Hydrographic Line (NHL; 44.652°N, 124.1 - 124.65°W), located west of Newport, Oregon. Additionally, GLOBEC-LTOP maintained a mooring slightly south of the NHL, nominally at 44.64°N, 124.30°W, on the 81-meter isobath. This location is referred to as NH-10, as it is located 10 nautical miles or 18.5 km west of Newport. A mooring was first deployed at NH-10 in August 1997. This subsurface mooring collected water column velocity data using an upward-looking acoustic Doppler current profiler. A second mooring with a surface expression was deployed at NH-10 starting in April 1999. This mooring included velocity, temperature and conductivity measurements throughout the water column as well as meteorological measurements. GLOBEC-LTOP and the Oregon State University (OSU) National Oceanographic Partnership Program (NOPP) provided funding for the NH-10 moorings from August 1997 to December 2004. Since June 2006, the NH-10 site has been occupied by a series of moorings operated and maintained by OSU with funding from the Oregon Coastal Ocean Observing System (OrCOOS), the Northwest Association of Networked Ocean Observing Systems (NANOOS), the Center for Coastal Margin Observation & Prediction (CMOP), and most recently the Ocean Observatories Initiative (OOI). While the objectives of these programs differed, each program contributed to long-term observing efforts with moorings routinely measuring meteorological and physical oceanographic variables. This article provides a brief description of each of the six programs, their associated moorings at NH-10, and our efforts to combine over twenty years of temperature, practical salinity, and velocity data into one coherent, hourly averaged, quality-controlled data set. Additionally, the data set includes best-fit seasonal cycles calculated at a daily temporal resolution for each variable using harmonic analysis with a three-harmonic fit to the observations. The stitched together, hourly NH-10 time series and seasonal cycles are available via Zenodo at https://doi.org/10.5281/zenodo.7582475.

Spatially gridded cross-shelf hydrographic sections and monthly climatologies from shipboard survey data collected along the Newport Hydrographic Line, 1997-2021.

The Oregon continental shelf is embedded within the northern California Current System, a wind-driven, eastern boundary system that includes the equatorward flowing California Current and the poleward flowing California Undercurrent. During spring and summer months, equatorward winds drive the upwelling of cold, nutrient-rich, and oxygen-poor waters from depth onto the shelf, fueling a highly productive marine ecosystem that supports several valuable commercial fisheries. This data article describes a time series of hydrographic data collected on a biweekly to monthly schedule from March 1997 to July 2021 along the Newport Hydrographic Line (NHL; 44.652°N, 124.1 - 124.65°W) located west of Newport, Oregon. The NHL, with its 2-4 week sampling rate and inclusion of biological data such as zooplankton net tows, is the only long-term, high-frequency dataset of its kind for the California Current and as such is crucial to understanding the connectivity between changes in ocean-climate and ecosystem structure and function. Data were collected using Sea-Bird Scientific conductivity, temperature, depth (CTD) profilers with associated dissolved oxygen sensors at seven stations located between 1.9 and 46.3 km from shore. Water depths for the seven stations range from 30 to 296 m. Data collected during each cruise were processed using Sea-Bird Scientific's Seasoft software package. These CTD station data were gridded to a 0.01° x 1 dbar longitude - pressure grid using linear interpolation to create cross-shelf hydrographic sections of temperature, practical salinity, potential density, spiciness, and dissolved oxygen. From the gridded section data, seasonal climatologies were calculated for each variable at each location in the longitude - pressure section using harmonic analysis with a three-harmonic fit to the gridded transect observations. The station data, gridded transect data and monthly climatologies for all five variables are available via Zenodo at https://doi.org/10.5281/zenodo.5814071.

Role of Sea Surface Physical Processes in Mixed-Layer Temperature Changes During Summer Marine Heat Waves in the Chile-Peru Current System.

We identified anomalously warm sea surface temperature (SST) events during 1980-2019 near the major upwelling center at Punta Lavapié in the central Chile-Peru Current System, using the European Centre for Medium-Range Weather Forecasts reanalysis and focusing on time scales of 10 days to 6 months. Extreme warm SST anomalies on these time scales mostly occurred in the austral summer, December through February, and had spatial scales of 1000s of km. By compositing over the 37 most extreme warm events, we estimated terms in a heat budget for the ocean surface mixed layer at the times of strongest warming preceding the events. The net surface heat flux anomaly is too small to explain the anomalous warming, even when allowing for uncertainty in mixed-layer depth. The composite mean anomaly of wind stress, from satellite ocean vector wind swath data, during the 37 anomalous warming periods has a spatial pattern similar to the resulting warm SST anomalies, analogous to previous studies in the California Current System. The weakened surface wind stress suggests reduced entrainment of cold water from below the mixed layer. Within 100-200 km of the coast, the typical upwelling-favorable wind stress curl decreases, suggesting reduced upwelling of cold water. In a 1000-km area of anomalous warming offshore, the typical downwelling-favorable wind stress curl also decreases, implying reduced downward Ekman pumping, which would allow mixed-layer shoaling and amplify the effect of the positive climatological summertime net surface heat flux.

The wind- and wave-driven inner-shelf circulation.

The inner continental shelf, which spans water depths ofa few meters to tens of meters, is a dynamically defined region that lies between the surf zone (where waves break) and the middle continental shelf (where the along-shelf circulation is usually in geostrophic balance). Many types of forcing that are often neglected over the deeper shelf-such as tides, buoyant plumes, surface gravitywaves, and cross-shelfwind stress-drive substantial circulations over the inner shelf. Cross-shelf circulation over the inner shelf has ecological and geophysical consequences: It connects the shore to the open ocean by transporting pollutants, larvae, phytoplankton, nutrients, and sediment. This review of circulation and momentum balances over the inner continental shelf contrasts prior studies, which focused mainly on the roles of along-shelfwind and pressure gradients, with recent understanding of the dominant roles of cross-shelf wind and surface gravity waves.