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With the growing number and increasing availability of shared-use instruments and observatories, observational data is becoming an essential part of application workflows and contributor to scientific discoveries in a range of disciplines. However, the corresponding growth in the number of users accessing these facilities coupled with the expansion in the scale and variety of the data, is making it challenging for these facilities to ensure their data can be accessed, integrated, and analyzed in a timely manner, and is resulting significant demands on their cyberinfrastructure (CI). In this paper, we present the design of a push-based data delivery framework that leverages emerging in-network capabilities, along with data pre-fetching techniques based on a hybrid data management model. Specifically, we analyze data access traces for two large-scale observatories, Ocean Observatories Initiative (OOI) and Geodetic Facility for the Advancement of Geoscience (GAGE), to identify typical user access patterns and to develop a model that can be used for data pre-fetching. Furthermore, we evaluate our data pre-fetching model and the proposed framework using a simulation of the Virtual Data Collaboratory (VDC) platform that provides in-network data staging and processing capabilities. The results demonstrate that the ability of the framework to significantly improve data delivery performance and reduce network traffic at the observatories’ facilities.

This paper explores the impact of the individual components of a coastal ocean observing system on estimates of the circulation derived from a state-of-the-art analysis and forecast system for the Mid-Atlantic Bight and Gulf of Maine. The foundation of these activities is the Regional Ocean Modeling System 4-dimensional variational (4D-Var) data assimilation platform, which is run in support of the Mid-Atlantic Regional Association Coastal Ocean Observing System as part of the U.S. Integrated Ocean Observing System. The specific focus of this study is on the impact of remote sensing observations from both space- and land-based platforms on estimates of cross-shelf transport in the vicinity of the National Science Foundation Ocean Observatories Initiative Pioneer array. Sea surface temperature (SST) and sea surface height (SSH) were found to have, on average, a similar impact on the transport estimates. However, during a typical 3-day 4D-Var assimilation cycle, approximately two orders of magnitude more observations of SST than SSH are used in the model, and closer analysis shows that each altimeter measurement has approximately 50 times more impact on the transport estimates than an individual SST observation. This highlights the value of altimetry data for ocean state estimation, and the significance of expanding the altimeter constellation. The observations that are most impactful of all are in situ measurements of temperature and salinity, which have typically 3-4 times more impact than an individual SSH datum. A robust geographical distribution of the observation impacts emerges across a range of transport metrics which results from the combined influence of space-time dynamical interpolation and error covariance information within the 4D-Var system. The observation impact calculations suggest that High Frequency (HF) radar estimates of surface currents have relatively little direct influence on cross-shelf transport estimates. However, quantification of the sensitivity of these same estimates to changes in the observing system indicate that HF radar observations indirectly provide important information. This is understood in the current system by appealing to the idea of borrowing strength from the field of statistics in which some observations (satellite remote sensing in the case considered here) can borrow strength from other, seemingly less important observations.

Large-scale scientific facilities provide a broad community of researchers and educators with open access to instrumentation and data products generated from geographically distributed instruments and sensors. This paper discusses key architectural design, deployment, and operational aspects of a production cyberinfrastructure for the acquisition, processing, and delivery of data from large scientific facilities using experiences from the National Science Foundation's Ocean Observatories Initiative. This paper also outlines new models for data delivery and opportunities for insights in a wide range of scientific and engineering domains as the volumes and variety of data from facilities grow.

The Ocean Observatories Initiative (OOI) of the National Science Foundation in the USA includes a coastal observatory called the OOI Pioneer Array, which is focused on understanding shelf/s...

The Cabled Observatory Vent Imaging Sonar (COVIS) was installed on the Ocean Observatories Initiative's Regional Cabled Array observatory at ASHES hydrothermal vent field on Axial Seamount in July 2018. The acoustic backscatter data recorded by COVIS in August–September 2018, in conjunction with in situ temperature measurements, are used to showcase and verify the use of COVIS for long‐term, quantitative monitoring of hydrothermal discharge. Specifically, sonar data processing generates three‐dimensional backscatter images of the buoyant plumes above major sulfide structures and two‐dimensional maps of diffuse flows within COVIS's field‐of‐view. The backscatter images show substantial changes of plume appearance and orientation that mostly reflect plume bending in the presence of ambient currents and potentially the variations of outflow fluxes. The intensity of acoustic backscatter decreases significantly for highly bent plumes as compared to nearly vertical plumes, reflecting enhanced mixing of plume fluids with seawater driven by ambient currents. A forward model of acoustic backscatter from a buoyancy‐driven plume developed in this study yields a reasonable match with the observation, which paves the way for inversely estimating the source heat flux of a hydrothermal plume from acoustic backscatter measurements. The acoustic observations of diffuse flows show large temporal variations on time scales of hours to days, especially at tidal frequencies, but no apparent long‐term trend. These findings demonstrate COVIS's ability to quantitatively monitor hydrothermal discharge from both focused and diffuse sources to provide the research community with key observational data for studying the linkage of hydrothermal activity with oceanic and geological processes.

Ocean observing systems are well-recognized as platforms for long-term monitoring of near-shore and remote locations in the global ocean. High-quality observatory data is freely available and accessible to all members of the global oceanographic community—a democratization of data that is particularly useful for early career scientists (ECS), enabling ECS to conduct research independent of traditional funding models or access to laboratory and field equipment. The concurrent collection of distinct data types with relevance for oceanographic disciplines including physics, chemistry, biology, and geology yields a unique incubator for cutting-edge, timely, interdisciplinary research. These data are both an opportunity and an incentive for ECS to develop the computational skills and collaborative relationships necessary to interpret large data sets. Here, we use observatory data to demonstrate the potential for these interdisciplinary approaches by presenting a case study on the water-column response to anomalous atmospheric events (i.e., major storms) on the shelf of the Mid-Atlantic Bight southwest of Cape Cod, United States. Using data from the Ocean Observatories Initiative (OOI) Pioneer Array, we applied a simple data mining method to identify anomalous atmospheric events over a four-year period. Two closely occurring storm events in late 2018 were then selected to explore the dynamics of water-column response using mooring data from across the array. The comprehensive ECS knowledge base and computational skill sets allowed identification of data issues in the OOI data streams and technologically sound characterization of data from multiple sensor packages to broadly characterize ocean-atmosphere interactions. An ECS-driven approach that emphasizes collaborative and interdisciplinary working practices adds significant value to existing datasets and programs such as OOI and has the potential to produce meaningful scientific advances. Future success in utilizing ocean observatory data requires continued investment in ECS education, collaboration, and research; in turn, the ECS community provides feedback, develops knowledge, and builds new tools to enhance the value of ocean observing systems. These findings present an argument for building a community of practice to augment ECS ocean scientist skills and foster collaborations to extend the context, reach, and societal utility of ocean science.

Axial Seamount is the most active submarine volcano in the NE Pacific Ocean, and is monitored by instruments connected to a cabled observatory (the US Ocean Observatories Initiative Cabled Array), ...

The Cabled Observatory Vent Imaging Sonar (COVIS) was installed on the Ocean Observatories Initiative’s Cabled Array observatory at ASHES hydrothermal vent field on Axial Seamount in July 2018. Diffuse hydrothermal flows are identified by maps made using the standard deviation of thephase change between pings separated in time by fractions of 1 s. The results demonstrate significant influences of ocean tides and bottom currents on diffuse hydrothermal discharge. The same data are used to estimate diffuse heat flux, providing two-dimensional maps of heat flux density at a rate of one per day. Sonar data are also used to generate three-dimensional backscatter images of the buoyant plumes above major sulfide structures. These backscatter images show substantial changes in plume bending in the presence of ambient currents and potentially the variations of outflow fluxes. The intensity of acoustic backscatter decreases significantly for highly bent plumes as compared to nearly vertical plumes, reflecting enhanced mixing of plume fluids with seawater driven by ambient currents. A forward model of acoustic backscatter from a buoyancy driven plume yields a reasonable match with the observation, paving the way for inversely estimating the source heat flux of a hydrothermal plume. [Work sponsored by NSF.]

A numerical model of ocean flow, hydrography, and transport is used to extrapolate observations of currents and hydrography and infer patterns of material flux in the deep ocean around Axial Seamount, a destination node of NSF's Ocean Observatories Initiative's Cabled Array. Using an inverse method, the model is made to approximate measured deep ocean flow around this site during a 35-day time period in the year 2002. The model is then used to extract month-long mean patterns and examine smaller-scale spatial and temporal variability around Axial. Like prior observations, model month-long mean currents flow anti-cyclonically around the seamount's summit in toroidal form with maximum speeds at 1500m depth of 10-11 cm/s. As a time mean, the temperature (salinity) anomaly distribution takes the form of a cold (briny) dome above the summit. Passive tracer material continually released at the location of the ASHES vent field exits the caldera primarily through its southern open end before filling the caldera. Once outside the caldera, the tracer circles the summit in clockwise fashion, fractionally re-entering the caldera over lower walls at its north end, while gradually bleeding southwestward during the modeled time period into the ambient ocean. A second tracer release experiment using a source of only two-day duration inside and near the CASM vent field at the northern end of the caldera suggests a residence time of the fluid at that locale of 8-9 days.

Natural methane gas release from the seafloor is a widespread phenomenon that occurs at cold seeps along most continental margins. Since their discovery in the early 1980s, seeps have been the focus of intensive research, partly aimed to refine the global carbon budget. However, deep-sea research is challenging and expensive and, to date, few works have successfully monitored the variability of methane gas release over long periods of time (> 1 year). Long-term monitoring is necessary to study the mechanisms that control seabed gas release. In 2017, the University of Bremen initiated the M3 project, which aims to study the temporal and spatial variability of gas emissions at the Southern Hydrate Ridge by acoustically monitoring gas effluxes over several years. Located at 800 m depth on the Cascadia accretionary prism offshore Oregon, the Southern Hydrate Ridge is one of the most studied seep sites where persistent but variable gas release has been observed for more than 20 years. We present the Southern Hydrate Ridge Overview Sonar, a long-range multibeam echosounder mounted on a rotator, which detects every gas bubble stream, or bubble plume, located in the study area. Built to resist to the harsh, corrosive conditions of the deep- sea, the instrument aims to produce data time-series that span over several years. It is powered and controlled from land through the Ocean Observatories Initiative’s Cabled Array observatory. The sonar was deployed and connected to the Cabled Array in June 2018 and started collecting data at fixed time intervals. This paper describes the design of the sonar, the dataflow, the post-processing steps that are required to process the enormous amount of data produced, as well as some preliminary data products.

This Mini Review is intended to describe the history, design, and summarize the performance of one class of mooring used by the Ocean Observatories Initiative.

Data and services provided by shared facilities, such as large-scale observing facilities, have become important enablers of scientific insights and discoveries across many science and engineering disciplines. Ensuring satisfactory quality of service can be challenging for facilities, due to their remote locations and to the distributed nature of the instruments, observatories, and users, as well as the rapid growth of data volumes and rates. This research explores how knowledge of the facilities usage patterns, coupled with emerging cyberinfrastructures can be leveraged to improve their performance, usability, and scientific impact. We propose a framework with a smart, internet-scale cache augmented with prefetching and data placement strategies to improve data delivery performance for scientific facilities. Our evaluations, which are based on the NSF Ocean Observatories Initiative, demonstrate that our framework is able to predict user requests and reduce data movements by more than 56% across networks.

Mesoscale eddies are ubiquitous features in the global oceans, having long been recognized to influence the distribution of physical, and biogeochemical properties in the marine environment. They have also been shown to contribute to shelf-slope exchange and to strongly influence biological processes, either by inducing vertical fluxes of nutrients that can support new production or by passively advecting phytoplankton. Observations from the Ocean Observatories Initiative(OOI) Pioneer Array suggest that coastal ocean dynamics are changing rapidly New England, changes to shelf-slope exchange may significantly affect nutrient transport between the deep ocean and the continental shelf, with consequences for higher trophic level productivity, including commercially harvested fish. Much has been learned about eddy characteristics and propagation properties over the last few years. In particular, recent studies have shown that mesoscale variability in the ocean occurs primarily as nonlinear eddies, which in contrast to linear waves can transport momentum, heat, mass, and chemical constituents present in the seawater as they propagate. Many studies have used satellite observations of sea level anomalies (SLA) or results from numerical models to describe the horizontal structure and kinematic properties of eddies in diverse oceanic settings. However, much remains to be learned about their vertical structure. Here we apply recently developed eddy detection and eddy tracking algorithms to high-resolution SLA fields in combination with data from conductivity-temperature-depth (CTD) sensors equipped in the Coastal Slocum Glider to investigate mesoscale eddies, especially their vertical structures, and their role on the New England Coast circulation.

The Ocean Observatories Initiative (OOI) is an integrated network that enables scientific investigation of interlinked physical, chemical, biological and geological processes throughout the global ocean. With near real-time data delivery via a common Cyberinfrastructure, the OOI instruments two contrasting ocean systems at three scales. The Regional Cabled Array instruments a tectonic plate and overlying ocean in the northeast Pacific, providing a permanent electro-optical cable connecting multiple seafloor nodes that provide high power and bandwidth to seafloor sensors and moorings with instrumented wire crawlers, all with speed-of-light interactive capabilities. Coastal arrays include the Pioneer Array, a relocatable system currently quantifying the New England shelf-break front, and the Endurance Array, a fixed system off Washington and Oregon with connections to the Regional Cabled Array. The Global Arrays host deep-ocean moorings and gliders to provide interdisciplinary measurements of the water column, mesoscale variability, and air-sea fluxes at critical high latitude locations. The OOI has unique aspects relevant to the international ocean observing community. The OOI uses common sensor types, verification protocols, and data formats across multiple platform types in diverse oceanographic regimes. OOI observing is sustained, with initial deployment in 2013 and 25 years of operation planned. The OOI is distributed among sites selected for scientific relevance based on community input and linked by important oceanographic processes. Scientific highlights include real-time observations of a submarine volcanic eruption, time-series observations of methane bubble plumes from Southern Hydrate Ridge off Oregon, observations of anomalous low-salinity pulses off Oregon, discovery of new mechanisms for intrusions of the Gulf Stream onto the shelf in the Middle Atlantic Bight, documentation of deep winter convection in the Irminger Sea, and observations of extreme surface forcing at the most southerly surface mooring in the world ocean.

The efficacy of an ocean observing, analysis, and forecasting system for the Mid-Atlantic Bight and the Gulf of Maine is explored using the concept of array modes. The analysis-forecast system is based on a triply nested configuration of the Regional Ocean Modeling System (ROMS) in conjunction with 4-dimensional variational (4D-Var) data assimilation. The array modes identify the degrees of freedom (df) of the signal and of the noise resolved by the observations, and are used here to quantify the extent to which the existing network of platforms and instruments are able to observe the ocean across different dynamical regimes ranging from quasi-geostrophic through the mesoscale and down to the sub-mesoscale. The ocean observing system includes the U.S. National Science Foundation’s Ocean Observatories Initiative Pioneer Array. In general, it is found that the df of the signal are largely associated with in situ observations from the Pioneer Array. On the other hand, a combination of satellite remote sensing and in situ observations potentially contribute to the df of the noise associated with uncertainties in the measurements. The array modes also provide information about the reduction in the expected analysis and forecast error covariance due to assimilating the observations. Here too observations from the Pioneer Array are found to significantly influence the veracity of the analyses and forecasts, and the circulation is instrumental in propagating observational information to other parts of the model domain. An approach is presented in which the array modes are used to quantify the impact of data assimilation on the expected forecast error covariance of forecasts initialized from the 4D-Var ocean state estimates. The advantage of this approach over others in common use is that it is independent of forecast error norm and circumvents the need for generating potentially large and costly ensembles.

Noise interferometry is the method of passively estimating acoustic propagation using ambient sound. It has been used for long-term ocean monitoring applications such as tomography, thermometry, and measuring flow velocity. Using noise interferometry, the time domain Greene’s function (TDGF) between two locations can be estimated. In this talk, we use 6 years (2015–2020) of acoustic data recorded by two hydrophones in the northeast Pacific Ocean to analyze the long-term TDGF. The hydrophones are deployed at the Cabled Array which is maintained by the Ocean Observatories Initiative (OOI). They are separated by 3.2 km, located on the ocean floor at a depth of 1500 m, and have a sampling rate of 200 Hz. We calculate the signal-to-noise ratio (SNR) of the TDGF estimate for different propagation paths and study how it varies for different average times, local shipping densities, and oceanographic variables such as sound speed. [Work supported by ONR.]

A nested configuration of the Regional Ocean Modeling System (ROMS) comprising three grids was used in conjunction with a 4-dimensional variational (4D-Var) data assimilation system to compute ocean state estimates of the Mid-Atlantic Bight (MAB). The three nested grids have a horizontal resolution ranging from ∼ 7 km to ∼ 0.8 km and capture circulation regimes that span the Gulf Stream western boundary current, through the mesoscale eddy field, and down to the rapidly evolving and energetic sub-mesoscale. All of these circulation regimes are challenging for any data assimilation system, yet the 4D-Var system was found to perform well across this range of space- and time-scales. The observational data used to constrain the ocean state estimates comes from a wide range of remote sensing, in situ, and mobile platforms. An adjoint-based procedure was used to compute the impact of each observing platform on several different indexes that describe the position of the MAB front, stratification, and associated cross-shelf exchange processes in the vicinity of the U.S. National Science Foundation’s Ocean Observatories Initiative Pioneer Array. The impact of observations from each observing platform on the chosen indexes varies across the three grids. It is a function of several factors that include the nature of the background circulation and the level of error assumed for the background ocean state and the observations. The geographic distribution of the observation impacts is remarkably robust across the various indexes and the three grids. In addition, observations that are both local to and remote from the target regions that define each index can exert a significant influence on the circulation. Variations in the observation impacts through time can be used to identify observations that exert unexpectedly large influence on the 4D-Var analyses (i.e, outliers), and routine monitoring of observation impacts is a useful indicator of the efficacy of different components of the observing system. Also, the observation impacts were found to be a useful performance indicator for the data assimilation system.

75 kHz ADCPs stationed near the 450-meter isobath within the Ocean Observatories Initiative Coastal Pioneer Array capture consistent patterns indicative of daily vertical migration (DVM) in depth profiles of both mean volume backscatter (MVB) and the vertical component of velocity (w). While the presence of DVM patterns is consistent throughout 2018 and 2019, attributes of MVB and w profiles are subject to variability within and across different seasons and years. This variability may be influenced by abiotic factors characteristic of the Mid-Atlantic Bight region such as the disruption of typical spring time temperature-salinity structures via frontal instability or the episodic introduction of warm-core rings. Additionally, biological community composition in the region may be reflected in MVB and w profiles given zooplankton survey data and knowledge of seasonal biophysical dynamics in the region, along with measured variability of other environmental properties observed by the Pioneer Array including dissolved oxygen concentration, chlorophyll-a concentration, and photosynthetically available radiation. Linking all of these factors, driven by long-term, stationary acoustical observations, can provide a useful framework for more directly assessing the impacts of aberrational physical phenomena on regional biological patterns.

Ground‐breaking measurements from the ocean observatories initiative Irminger Sea surface mooring (60°N, 39°30′W) are presented that provide the first in situ characterization of multiwinter surface heat exchange at a high latitude North Atlantic site. They reveal strong variability (December 2014 net heat loss nearly 50% greater than December 2015) due primarily to variations in frequency of intense short timescale (1–3 days) forcing. Combining the observations with the new high resolution European Centre for Medium Range Weather Forecasts Reanalysis 5 (ERA5) atmospheric reanalysis, the main source of multiwinter variability is shown to be changes in the frequency of Greenland tip jets (present on 15 days in December 2014 and 3 days in December 2015) that can result in hourly mean heat loss exceeding 800 W/m2. Furthermore, a new picture for atmospheric mode influence on Irminger Sea heat loss is developed whereby strongly positive North Atlantic Oscillation conditions favor increased losses only when not outweighed by the East Atlantic Pattern.

The Ocean Observatories Initiative (OOI) is a United States National Science Foundation-funded major research facility that provides continuous observations of the ocean and seafloor from coastal and open ocean locations in the Atlantic and Pacific. Multiple cycles of OOI infrastructure deployment, recovery, and refurbishment have occurred since operations began in 2014. This heterogeneous ocean observing infrastructure with multidisciplinary sampling in important but challenging locations has provided new scientific and engineering insights into the operation of a sustained ocean observing system. This paper summarizes the challenges, successes, and failures experienced to date and shares recommendations on best practices that will be of benefit to the global ocean observing community.

We use an eddy-resolving, regional ocean biogeochemical model to investigate the main variables and processes responsible for the climatological spatio-temporal variability of pCO2 and the air-sea CO2 fluxes in the southwestern Atlantic Ocean. Overall, the region acts as a sink of atmospheric CO2 south of 30° S, and is close to equilibrium with the atmospheric CO2 to the north. On the shelves, the ocean acts as a weak source of CO2, except for the mid/outer shelves of Patagonia, which act as sinks. In contrast, the inner shelves and the low latitude open ocean of the southwestern Atlantic represent source regions. Observed nearshore-to-offshore and meridional pCO2 gradients are well represented by our simulation. A sensitivity analysis shows the importance of the counteracting effects of temperature and dissolved inorganic carbon (DIC) in controlling the seasonal variability of pCO2. Biological production and solubility are the main processes regulating pCO2, with biological production being particularly important on the shelves. The role of mixing/stratification in modulating DIC, and therefore surface pCO2, is shown in a vertical profile at the location of the Ocean Observatories Initiative (OOI) site in the Argentine Basin (42° S, 42° W).

The Ocean Observatories Initiative air‐sea flux mooring deployed at 54.08°S, 89.67°W, in the southeast Pacific sector of the Southern Ocean, is the farthest south long‐term open ocean flux mooring ever deployed. Mooring observations (February 2015 to August 2017) provide the first in situ quantification of annual net air‐sea heat exchange from one of the prime Subantarctic Mode Water formation regions. Episodic turbulent heat loss events (reaching a daily mean net flux of −294 W/m2) generally occur when northeastward winds bring relatively cold, dry air to the mooring location, leading to large air‐sea temperature and humidity differences. Wintertime heat loss events promote deep mixed layer formation that lead to Subantarctic Mode Water formation. However, these processes have strong interannual variability; a higher frequency of 2 σ and 3 σ turbulent heat loss events in winter 2015 led to deep mixed layers (>300 m), which were nonexistent in winter 2016.

Large scale observatories are shared-use resources that provide open access to data from geographically distributed sensors and instruments. This data has the potential to accelerate scientific discovery. However, seamlessly integrating the data into scientific workflows remains a challenge. In this paper, we summarize our ongoing work in supporting data-driven and data-intensive workflows and outline our vision for how these observatories can improve large-scale science. Specifically, we present programming abstractions and runtime management services to enable the automatic integration of data in scientific workflows. Further, we show how approximation techniques can be used to address network and processing variations by studying constraint limitations and their associated latencies. We use the Ocean Observatories Initiative (OOI) as a driving use case for this work.

An autonomous sensor platform powered by a benthic microbial fuel cell (BMFC) has been developed and deployed to supply hourly dissolved oxygen (O 2 ), temperature and conductivity measurements from a remote location in the core of the oxygen minimum zone of the northeast Pacific. The platform uses a compact acoustic modem to both store and transmit sensor and energy harvesting measurements. Initial results from the first 150 days of operation are reported. The platform's sensor measurements compare well to data from a nearby cabled benthic experiment package maintained as a component of the “Endurance Array” of the U.S. Ocean Observatories Initiative. The promising performance of our platform makes it a candidate for an expanded O2 observing system needed to provide global O2 inventories through time. Only through analyses of wide-spread long-term measurements can ocean scientists corroborate model predictions that key sectors of the ocean are losing oxygen due to climate change.

The Ocean Observatories Initiative (OOI) is directed to operate and maintain arrays of moored and mobile assets in six locations around the globe. These locations include two coastal arrays off of the east and west coasts of the United States and four global arrays in the Southern Ocean, Argentine Basin, Irminger Sea, and North Pacific. These arrays are currently operational, supplying oceanographic data to the scientific community in near real time. The moorings deployed at these arrays include a number of technological innovations in the field, resulting in some of the most complex mooring systems in use. There are several different classes of moorings in use by the OOI project. This paper will detail the primary systems of the Coastal Surface Moorings (CSMs) deployed off the east coast of the United States at the OOI Pioneer Array. The innovative systems designed into a CSM include networking and telemetry, power storage and generation, and electromechanical systems that span the distance from the seafloor to the surface. The mooring configuration includes a surface buoy with instrumentation at the air-sea interface, telemetry systems mounted over 4.5 meters above the sea surface, and power generation systems. A Near Surface Instrument Frame (NSIF) with instrumentation is located 5 meters below the surface. A MultiFunction Node (MFN) with instrumentation, communication, power distribution, and a recoverable anchor assembly is located on the sea floor. There are currently nine single board computers (SBCs), with room for expansion, distributed throughout various locations on the mooring. Several areas of technology had to be developed in order to implement this capability. The SBCs had to be networked together, creating a need for high speed connections, both to shore, and to the sea floor. The number of sensors and computers, and the use of high speed telemetry, translates to a significantly higher hotel power load than a typical offshore moored system. This power requirement led to the development of a power system with enough reserve storage and power generation to maintain operation over 6-month deployments.

The National Science Foundation-funded Ocean Observatories Initiative (OOI) maintains a series of coastal and oceanic monitoring sites that consists of a multitude of physical and biological sensors. As part of this program, OOI has collected continuous, broadband passive acoustic data along the continental shelf and slope off Newport, Oregon since 2016. The Coastal Endurance cabled array consists of two mooring lines that straddle the Columbia River plume, and capture data from this nutrient rich upwelling site along the northeast Pacific coast. In addition to this instrumentation, underwater gliders conduct regular transects to provide better spatial resolution of coastal ocean parameters in the region. Representative data from the continental slope and seamount recording sites of the Coastal Endurance Array were reviewed for vocally active marine mammals. Physical oceanographic variables collected concurrently from the mooring line instrumentation and coastal gliders were used to spatially and temporally characterize the regional marine mammal habitat. This effort demonstrates applications for use of OOI’s accessible, multi-instrument platform for conducting marine mammal ecosystem studies.

The Cabled Observatory Vent Imaging Sonar (COVIS) was installed on the Ocean Observatories Initiative’s Cabled Array observatory at ASHES hydrothermal vent field on Axial Seamount in July 2018. The acoustic backscatter data recorded by COVIS, in conjunction with in-situ temperature measurements, are used to investigate the temporal and spatial variations of hydrothermal venting within COVIS’s field-of-view. Areas in which diffuse hydrothermal flow is significant are identified by maps made using the standard deviation of the phase change between pings separated in time by fractions of 1 s. The results demonstrate significant influences of ocean tides and bottom currents on diffuse hydrothermal discharge. Comparison with local seismicity shows a small positive correlation between the areal coverage of diffuse hydrothermal discharge and the seismic activity in the vicinity of the vent field. This finding reveals an intimate connection between hydrothermal activity and geological processes during the dynamic period leading up to the next eruption of Axial Seamount. [Work sponsored by NSF.]

During the first two weeks of November 2009, a field experiment was conducted in the Mid-Atlantic Bight region to demonstrate a coastal ocean observatory that can collect observations from heterogeneous platforms and forecast fields from four different ocean models, provide multi-model ensemble forecasts based on either an equal weighting (EQ) or objective weighting (OBJ) method, and use model forecasts in a path planning system to relocate autonomous gliders. This experiment is a prototype for the command and control component of cyberinfrastructure of the Ocean Observatories Initiative funded by the National Science Foundation. The four individual models use different forcing fields, boundary conditions and data assimilation techniques, and have resolutions varying from 2 km to 15 km. Our results indicate that for sea surface temperature and surface currents, the OBJ ensemble outperforms the four individual models, while the EQ ensemble can also provide an effective way to improve individual model forecasts. In terms of glider path planning, the OBJ ensemble has a performance similar to the best individual model, which has the finest horizontal resolution. This field experiment demonstrates the first-ever use of ensemble current forecasts to guide glider path planning in the context of real-time data collection and ocean model forecasting.

The magma reservoir in geophysical volcano plumbing models is often modeled as a simple geometric volume, filled with magma of uniform properties. However, the constraints on reservoir size and magma properties in volcano roots are typically indirect and poor. Axial Seamount, a volcano at a depth of about 1500 m on the Juan de Fuca mid-oceanic ridge in the Pacific Ocean, has both high-resolution seismic images of its subsurface magma and detailed results from monitoring of its most recent eruption and associated seismicity and ground deformation. The 2015 eruption at Axial Seamount is the best monitored submarine eruption so far because of observations made possible by the Ocean Observatories Initiative, and seismic imaging of magma at this volcano is better than in most other environments because of advanced analysis of extensive seismic reflection profiling at sea and the relatively simple volcano structure. This allows new understanding compared to findings from earlier observations from monitored rifting episodes on land. Geophysical magma plumbing models, in general, may need to allow for more complexities, namely, spatial heterogeneities in magma composition, melt content, and location of major volume changes within a single magma dominated crustal volume during eruptions.

Volcanology Axial Seamount is a large and active submarine volcano along the Juan de Fuca midocean ridge off the coast of the western United States. Eruptions in 1998 and 2011 were followed by periods of magma recharge, making it an ideal location to include in the Ocean Observatories Initiative Cabled Array. Wilcock et al. present real-time seismic data from the most recent eruption in April 2015 that allow the tracking of magma before and during eruption. Nooner and Chadwick show that eruptions are predictable on the basis of deformation data. As magma pools underneath it, Axial Seamount inflates and erupts when the inflation hits a threshold. Both studies elucidate the dynamics of submarine volcanoes, which vastly outnumber their aboveground counterparts. Science , this issue p. [1395][1], p. [1399][2] [1]: /lookup/doi/10.1126/science.aah5563 [2]: /lookup/doi/10.1126/science.aah4666

The Cabled Array portion of the National Science Foundation funded Ocean Observatories Initiative is a large scale, high bandwidth and high power subsea science network developed by the University of Washington Applied Physics Laboratory. Part of that system is a set of moorings and winched profilers which continuously scan the upper 200m of the ocean at their deployment sites. The profilers have been in operation since July 2014 and have accumulated a significant performance record. The general design approach, performance results and lessons learned are described.

The Ocean Observatories Initiative (OOI) consists of seven research sites with over 800 instruments collecting ocean, seafloor, and meteorological data in the world's oceans, extending from the Irminger Sea to the Southern Ocean. The scale with which data are produced from the instruments and their platforms presents key challenges, including how to (1) build data and information management infrastructure that associates measurements from multiple instruments for concurrent observations, (2) develop data delivery mechanisms that meet a variety of needs, (3) ensure timely release of data, and (4) formulate capabilities to provide stable, longterm support for research and societal needs. As a strategy for maintenance of the sustained, large-scale, and variety of scientific observations collected, the OOI Cyberinfrastructure (CI) developed an end-to-end system designed to store, query, process, and disseminate the compiled information. These resources include raw instrument values and derived data products, metadata associated with instrument and platform deployments (e.g., deployment dates, water depths, instrument manufacturer, etc.), calibration coefficients, data provenance and descriptors of computational algorithms and transformation functions, and other related outputs. As with many data and information management systems, the need to monitor and improve upon the performance of the various interrelated components of the CI is an integral part in establishing the success of the system. For this reason, the data evaluation team at Rutgers initiated an end-to-end system data quality audit that ensures the system can accurately and completely deliver data within the required specifications. This was applied to a subset of representative platforms for all instrument types. Thus, based on specific system failures that can prevent production of quality data products, we prepared a set of tests and built tools that function as a troubleshooting method for system repair and enhancement. The method was used to report on the system's ability to: (a) Respond to data queries (b) Provide links to data product files (c) Produce all relevant data products (d) Produce correct provenance information (e) Produce quality science data products (f) Parse data with the correct specifications and the correct number of particles (g) Calculate different data levels with correct dimensions and units

The Ocean Observatories Initiative Cabled Array has provided an unprecedented real-time window on the dynamics of Axial Volcano since fall 2014. In April and May of 2015, for the first time, researchers on shore were able to monitor an eruption event as it happened. The seismic, deformation and acoustic signals sent to shore were analyzed to determine the precise locations of diking events, followed hours later by acoustic impulses corresponding to lava expulsion from the seafloor. Although these locations informed follow-up Autonomous Underwater Vehicle (AUV) mapping expeditions which produced high resolution bathymetry, to date, the evolution of an eruptive event and its immediate impact on the surrounding ecosystem have not been observed. Although the 70,000 km-long mid ocean ridge (MOR) must generate many hundreds of powerful, transient events every year, they have never been characterized as they form. We envision a Resident AUV with in situ charging and data download capabilities, shore-based mission control, and an array of bottom-mounted acoustic positioning beacons that can concurrently be used as a multi-hop sensor network. This system will provide unprecedented observing capabilities before, during, and after the next eruption and formation of the highly energetic eruptive (mega) plume. AUV capabilities will include high-resolution bathymetry, high definition video and still imagery, and 3-D water chemistry and microbial sampling throughout the water column, while the acoustic array will monitor horizontal and vertical deformation.