AUV observations of the diurnal surface layer in the North Atlantic salinity maximum

Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 44 (2014): 1595–1604, doi:10.1175/JPO-D-13-0140.1.Autonomous underwater vehicle (AUV) surveys of temperature, salinity, and velocity in the upper 10 m of the ocean were carried out in low-wind conditions near the North Atlantic surface salinity maximum as part of the Salinity Processes in the Upper Ocean Regional Study (SPURS) project. Starting from a well-mixed state, the development, deepening, and decay of a warm salty diurnal surface layer was observed at <1-h resolution. The evaporation rate deduced from the freshwater anomaly of the layer corroborates measurements at a nearby flux mooring. Profiles within a few hundred meters of the stationary research vessel showed evidence of mixing, highlighting the effectiveness of AUVs for collecting uncontaminated time series of near-surface thermohaline structure. A two-dimensional horizontal subsurface survey within the diurnal warm layer revealed coherent warm and cool bands, which are interpreted as internal waves on the diurnal thermocline.NASA supported this work under Grant NNX11AE82G.2014-12-0

OC449-09 Data Report : St. Thomas, USVI to Bermuda, December 1-10, 2008

Data collected during multiple surveys of hydrography, velocity, and biological quantities are presented from a 9-day cruise aboard the R/V Oceanus near the island of St. Thomas, USVI and a subsequent transit to Bermuda during December, 2008. This cruise (OC449-09) was undertaken primarily to field test a newly acquired towed-undulating body, the Scanfish. The Scanfish and a second towed body, the Video Plankton Recorder (VPR), were used to survey hydrographic, optical, and biological properties north and south of St. Thomas. Conductivity-Temperature-Depth (CTD) casts and plankton net-tows were made at locations along the survey transects for inter-comparison. The VPR was also used to profile conditions between St. Thomas and Bermuda during transit. An overview of the cruise is given along with descriptions of the data collection methods, processing steps taken, and data products available for distribution.Funding for this research was provided by the King Abdullah University of Science and Technology (KAUST) under a cooperative research agreement with Woods Hole Oceanographic Institution

Slocum gliders provide accurate near real-time estimates of baleen whale presence from human-reviewed passive acoustic detection information

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Baumgartner, M. F., Bonnell, J., Corkeron, P. J., Van Parijs, S. M., Hotchkin, C., Hodges, B. A., Thornton, J. B., Mensi, B. L., & Bruner, S. M. Slocum gliders provide accurate near real-time estimates of baleen whale presence from human-reviewed passive acoustic detection information. Frontiers in Marine Science, 7, (2020):100, doi:10.3389/fmars.2020.00100.Mitigating the effects of human activities on marine mammals often depends on monitoring animal occurrence over long time scales, large spatial scales, and in real time. Passive acoustics, particularly from autonomous vehicles, is a promising approach to meeting this need. We have previously developed the capability to record, detect, classify, and transmit to shore information about the tonal sounds of baleen whales in near real time from long-endurance ocean gliders. We have recently developed a protocol by which a human analyst reviews this information to determine the presence of marine mammals, and the results of this review are automatically posted to a publicly accessible website, sent directly to interested parties via email or text, and made available to stakeholders via a number of public and private digital applications. We evaluated the performance of this system during two 3.75-month Slocum glider deployments in the southwestern Gulf of Maine during the spring seasons of 2015 and 2016. Near real-time detections of humpback, fin, sei, and North Atlantic right whales were compared to detections of these species from simultaneously recorded audio. Data from another 2016 glider deployment in the same area were also used to compare results between three different analysts to determine repeatability of results both among and within analysts. False detection (occurrence) rates on daily time scales were 0% for all species. Daily missed detection rates ranged from 17 to 24%. Agreement between two trained novice analysts and an experienced analyst was greater than 95% for fin, sei, and right whales, while agreement was 83–89% for humpback whales owing to the more subjective process for detecting this species. Our results indicate that the presence of baleen whales can be accurately determined using information about tonal sounds transmitted in near real-time from Slocum gliders. The system is being used operationally to monitor baleen whales in United States, Canadian, and Chilean waters, and has been particularly useful for monitoring the critically endangered North Atlantic right whale throughout the northwestern Atlantic Ocean.Funding for this project was provided by the Environmental Security Technology Certification Program of the U.S. Department of Defense and the U.S. Navy’s Living Marine Resources Program

CLIMODE bobber data report : July 2005 - May 2009

This report summarizes direct observations of Eighteen Degree Water (EDW) subduction and dispersal within the subtropical gyre of the North Atlantic Ocean. Forty acoustically-tracked bobbing, profiling floats (“bobbers”) were deployed to study the formation and dispersal of EDW in the western North Atlantic. The unique bobber dataset described herein provides insight into the evolution of EDW by means of direct, eddy-resolving measurement of EDW Lagrangian dispersal pathways and stratification. Bobbers are modified Autonomous Profiling Explorer (APEX) profiling floats which actively servo their buoyancy control mechanism to follow a particular isothermal surface. The CLIVAR Mode Water Dynamics Experiment (CLIMODE) bobbers tracked the 18.5°C temperature surface for 3 days, then bobbed quickly between the 17°C and 19°C isotherms. This cycle was repeated for one month, after which each bobber profiled to 1000 m before ascending to the surface to transmit data. The resulting dataset (37/40 tracked bobbers; more than half still profiling as of January 2010) yields well-resolved trajectories, unprecedented velocity statistics in the core of the subducting and spreading EDW, and detailed information about the Lagrangian evolution of EDW thickness and vertical structure. This report provides an overview of the experimental procedure employed and summarizes the initial processing of the bobber dataset.Funding was provided by the National Science Foundation under Grant No. OCE-0424492

A thin layer of phytoplankton observed in the Philippine Sea with a synthetic moored array of autonomous gliders

Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C10020, doi:10.1029/2009JC005317.A synthetic moored array composed of five buoyancy-propelled autonomous underwater gliders was used to characterize mesoscale variability and phytoplankton distribution in a 100 km × 100 km domain in the Philippine Sea east of Luzon Strait for 10 days in May 2004. The study area, located east of the Kuroshio near the subtropical front, is dominated by strong internal tides, by energetic westward-propagating mesoscale eddies with azimuthal velocities exceeding 50 cm/s, and by a deep (130 m) maximum in chlorophyll fluorescence. Each glider in the array was instructed to maintain geographic position while repeatedly profiling to 200-m depth. Good station-keeping performance enabled the resulting series of vertical profiles to be interpreted in the same manner as a physically moored chain of instruments. Although organized primarily as a demonstration of glider capabilities, this field exercise provides a unique data set for examining biological-physical interactions in the open ocean. Here we report on the evolution of a thin layer of phytoplankton observed near the deep chlorophyll maximum. Coincident observations of fine structure in temperature and salinity suggest that the thinning process of this layer was driven primarily by physical forcing, most probably vertical shear associated with energetic diurnal internal waves, as opposed to a biological mechanism, such as convergent swimming, grazing, or spatial variation in growth rate.The Office of Naval Research provided support for fieldwork and analysis through grants N-00014-00-1-0256 and N-00014-05-1-0367

Salinity and temperature balances at the SPURS central mooring during fall and winter

Author Posting. © The Oceanography Society, 2015. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 28, no. 1 (2015): 56-65, doi:10.5670/oceanog.2015.06.One part of the Salinity Processes in the Upper-ocean Regional Study (SPURS) field campaign focused on understanding the physical processes affecting the evolution of upper-ocean salinity in the region of climatological maximum sea surface salinity in the subtropical North Atlantic (SPURS-1). An upper-ocean salinity budget provides a useful framework for increasing this understanding. The SPURS-1 program included a central heavily instrumented mooring for making accurate measurements of air-sea surface fluxes, as well as other moorings, Argo floats, and gliders that together formed a dense observational array. Data from this array are used to estimate terms in the upper-ocean salinity and heat budgets during the SPURS-1 campaign, with a focus on the first several months (October 2012 to February 2013) when the surface mixed layer was becoming deeper, fresher, and cooler. Specifically, we examine the salinity and temperature balances for an upper-ocean mixed layer, defined as the layer where the density is within 0.4 kg m–3 of its surface value. The gross features of the evolution of upper-ocean salinity and temperature during this fall/winter season are explained by a combination of evaporation and precipitation at the sea surface, horizontal transport of heat and salt by mixed-layer currents, and vertical entrainment of fresher, cooler fluid into the layer as it deepened. While all of these processes were important in the observed seasonal (fall) freshening at this location in the salinity-maximum region, the variability of salinity on monthly-to-intraseasonal time scales resulted primarily from horizontal advection.J.T. Farrar, A.J. Plueddemann, J.B. Edson, and the deployment of the central mooring were supported by NASA grant NNX11AE84G. L. Rainville, C. Lee, C. Eriksen, and the Seaglider program were supported by NASA grant NNX11AE78G. R. Schmitt was supported by NSF grant OCE-1129646. B. Hodges and D. Fratantoni were supported by NASA grant NNX11AE82G. The Prawler moorings were funded by PMEL. The data analysis was also supported by NASA grant NNX14AH38G

Promoting co-existence between humans and venomous snakes through increasing the herpetological knowledge base

Snakebite incidence at least partly depends on the biology of the snakes involved. However, studies of snake biology have been largely neglected in favour of anthropic factors, with the exception of taxonomy, which has been recognised for some decades to affect the design of antivenoms. Despite this, within-species venom variation and the unpredictability of the correlation with antivenom cross-reactivity has continued to be problematic. Meanwhile, other aspects of snake biology, including behaviour, spatial ecology and activity patterns, distribution, and population demography, which can contribute to snakebite mitigation and prevention, remain underfunded and understudied. Here, we review the literature relevant to these aspects of snakebite and illustrate how demographic, spatial, and behavioural studies can improve our understanding of why snakebites occur and provide evidence for prevention strategies. We identify the large gaps that remain to be filled and urge that, in the future, data and relevant metadata be shared openly via public data repositories so that studies can be properly replicated and data used in future meta-analyses