765 research outputs found
Status report on MicroSat data telemtery
The intent of this project was to test and evaluate a new data collection concept; that of utilizing a "store and forward" message
system in a low earth orbiting satellite, and to determine its suitabilty for oceanographic data telemetry. This new generation of
satellites, dubbed "MicroSats" because of their small size (a 9 in. cube), was developed by the Amateur Radio Satellite
Corporation (AMSAT) to complement the existing HF and VHG terrestral Packet data switching networks.Funding was provided by the Office of Naval Research
under Contract No. N00014-90-0013
SOFAR float Mediterranean outflow experiment data from the second year, 1985-86
In October, 1984, the Woods Hole Oceanographic Institution SOFAR float
group began a three-year-long field program to observe the low frequency currents
in the Canary Basin. The principal scientific goal was to learn how advection and
diffusion by these currents determine the shape and amplitude of the
Mediterranean salt tongue. Fourteen floats were launched at a depth of 1100 min
a cluster centered on 32°N, 24°W, and seven other floats were launched
incoherently along a north/south line from 24°N to 37°N. At the same time
investigators from Scripps Institution of Oceanography and the University of
Rhode Island used four other SOFAR floats to tag a Meddy, a submesoscale lens
of Mediterranean water.
In October, 1985, seven additional floats were launched, four in three different
Meddies, one of which was tracked during year 1. This report describes the second
year of the floats launched in 1984 and the first year of the ones launched in 1985.
Approximately 41 years of float trajectories were produced during the first two
years of the experiment. One of the striking accomplishments is the successful
tracking of one Meddy over two full years plus the tracking of two other Meddies
during the second year.Funding was provided by the National Science Foundation under
grant Numbers OCE 82-14066 and OCE 86-00055
Gulf Stream recirculation experiment - Part II
This report presents trajectories and time series of velocity, pressure, and
temperature for twelve neutrally-buoyant floats launched during the Gulf Stream
Recirculation EXperiment (GUSREX) and two from earlier experiments, that
continued to operate after May 1982. These float data were obtained from
Autonomous Listening Stations (ALSs) deployed from May 1982 to August 1985.Funding was provided by the national Science Foundation under Grant Numbers OCE 81-09145 and OCE 81-1746
FASINEX (Frontal Air-Sea Interaction Experiment) moored instrumentation
In 1986, FASINEX, a Frontal Air-Sea Interaction Experiment,
a multi-investigator cooperative experiment, was conducted
to study the role of horizontal variability in air-sea
interaction in the persistent front formed in the
subtropical convergence zone south of Bermuda. Aimed at
investigating all aspects of the atmospheric and oceanic
variables related to the formation and maintenance of the
front, an array of meteorological and current meter moorings
was deployed by the Woods Hole Oceanographic Institution
Buoy Group in 5400 meters of water . Two subsurface current
meter moorings were deployed in October, 1984; five surface
meteorological and current meter moorings and four Profiling
Current Meter (PCM) moorings were set in January 1986 . All
except one PCM mooring, which was lost, were recovered in
June 1986. This report discusses the extensive preparations
of, and modifications to, the Woods Hole Oceanographic
Institution Buoy Group instruments placed on the five
surface moorings. The equipment included 30 vector
measuring current meters, ten vector averaging current
meters and five vector averaging wind recorders .Funding was provided by the Office of Naval Research
under contract Number N00014-84-C-0134
WHOI 260Hz Sound Source - Tuning and Assembly
Sound sources are designed to provide subsea tracking and re‐location of RAFOS floats and other Lagrangian drifters listening at 260Hz. More recently sweeps have been added to support FishChip tracking at 262Hz. These sources must be tuned to the water properties where they are to be deployed as they have a fairly narrow bandwidth. The high‐Q resonator’s bandwidth is about 4Hz. This report documents the tuning, and provides an overview of the sound source assembly.Funding was provided by the National Science Foundation under Grant No. OCE0175636
The Indo-U.S. Library of Coude Feed Stellar Spectra
We have obtained spectra for 1273 stars using the 0.9m Coud\'e Feed telescope
at Kitt Peak National Observatory. This telescope feeds the coud\'e
spectrograph of the 2.1m telescope. The spectra have been obtained with the #5
camera of the coud\'e spectrograph and a Loral 3K X 1K CCD. Two gratings have
been used to provide spectral coverage from 3460 \AA to 9464 \AA, at a
resolution of 1\AA FWHM and at an original dispersion of 0.44 \AA/pixel.
For 885 stars we have complete spectra over the entire 3460 \AA to 9464 \AA
wavelength region (neglecting small gaps of 50 \AA), and partial spectral
coverage for the remaining stars. The 1273 stars have been selected to provide
broad coverage of the atmospheric parameters T, log g, and [Fe/H], as
well as spectral type. The goal of the project is to provide a comprehensive
library of stellar spectra for use in the automated classification of stellar
and galaxy spectra and in galaxy population synthesis. In this paper we discuss
the characteristics of the spectral library, viz., details of the observations,
data reduction procedures, and selection of stars. We also present a few
illustrations of the quality and information available in the spectra. The
first version of the complete spectral library is now publicly available from
the National Optical Astronomy Observatory (NOAO) via FTP and HTTP.Comment: 18 pages, 6 figures, 4 table
The neutrally buoyant sediment trap: two decades of progress
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estapa, M., Valdes, J., Tradd, K., Sugar, J., Omand, M., & Buesseler, K. The neutrally buoyant sediment trap: two decades of progress. Journal of Atmospheric and Oceanic Technology, 37(6), (2020): 957-973, https://doi.org/10.1175/JTECH-D-19-0118.1.The biological carbon flux from the ocean’s surface into its interior has traditionally been sampled by sediment traps, which physically intercept sinking particulate matter. However, the manner in which a sediment trap interacts with the flow field around it can introduce hydrodynamic biases, motivating the development of neutral, self-ballasting trap designs. Here, the performance of one of these designs, the neutrally buoyant sediment trap (NBST), is described and evaluated. The NBST has been successfully used in a number of scientific studies since a prototype was last described in the literature two decades ago, with extensive modifications in subsequent years. Originated at Woods Hole Oceanographic Institution, the NBST is built around a profiling float and carries cylindrical collection tubes, a feature that distinguishes it from other neutral traps described in the literature. This paper documents changes to the device that have been implemented over the last two decades, including wider trap tubes; Iridium Communications, Inc., satellite communications; and the addition of polyacrylamide gel collectors and optical sedimentation sensors. Information is also provided with the intent of aiding the development of similar devices by other researchers, including the present adaptation of the concept to utilize commercially available profiling float hardware. The performance of NBSTs built around commercial profiling floats is comparable to NBSTs built around customized floats, albeit with some additional operational considerations. Data from recent field studies comparing NBSTs and traditional, surface-tethered sediment traps are used to illustrate the performance of the instrument design. Potential improvements to the design that remain to be incorporated through future work are also outlined.Funding supporting this work has come from multiple sources over the years: the NSF Chemical Oceanography and Carbon and Water programs (most recently OCE-1660012 and OCE-1659995), the NASA Ocean Biology and Biogeochemistry and New Investigator programs (80NSSC17K0662 and NNX14AM01G), and the Woods Hole Oceanographic Institution Technology Award
An autonomous, in situ light-dark bottle device for determining community respiration and net community production
Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography-Methods 16 (2018): 323-338, doi:10.1002/lom3.10247.We describe a new, autonomous, incubation-based instrument that is deployed in situ to
determine rates of gross community respiration and net community production in marine and aquatic
ecosystems. During deployments at a coastal pier and in the open ocean, the PHORCYS
(PHOtosynthesis and Respiration Comparison-Yielding System) captured dissolved oxygen fluxes
over hourly timescales that were missed by traditional methods. The instrument uses fluorescence-quenching optodes fitted into separate light and dark chambers; these are opened and closed with
piston-like actuators, allowing the instrument to make multiple, independent rate estimates in the
course of each deployment. Consistent with other studies in which methods purporting to measure
the same metabolic processes have yielded divergent results, respiration rate estimates from the
PHORCYS were systematically higher than those calculated for the same waters using a traditional
two-point Winkler titration technique. However, PHORCYS estimates of gross respiration agreed
generally with separate incubations in bottles fitted with optode sensor spots. An Appendix describes
a new method for estimating uncertainties in metabolic rates calculated from continuous dissolved
oxygen data. Multiple successful, unattended deployments of the PHORCYS represent a small step
toward fully autonomous observations of community metabolism. Yet the persistence of unexplained
disagreements among aquatic metabolic rate estimates — such as those we observed between rates
calculated with the PHORCYS and two existing, widely-accepted bottle-based methods — suggests
that a new community intercalibration effort is warranted to address lingering sources of error in
these critical measurements.This research was supported by the U.S.
National Science Foundation (awards OCE-1155438 to B.A.S.V.M., J.R.V., and R.G.K., and OCE-
1059884 to B.A.S.V.M.), the Woods Hole Oceanographic Institution through a Cecil and Ida Green
Foundation Innovative Technology Award and an Interdisciplinary Science Award, and a U.S.
Environmental Protection Agency (EPA) STAR Graduate Fellowship to J.R.C. under Fellowship
Assistance Agreement no. FP-91744301-0
Brain-predicted age difference mediates the association between PROMIS sleep impairment, and self-reported pain measure in persons with knee pain
Knee pain, the most common cause of musculoskeletal pain (MSK), constitutes a severe public health burden. Its neurobiological causes, however, remain poorly understood. Among many possible causes, it has been proposed that sleep problems could lead to an increase in chronic pain symptomatology, which may be driven by central nervous system changes. In fact, we previously found that brain cortical thickness mediated the relationship between sleep qualities and pain severity in older adults with MSK. We also demonstrated a significant difference in a machine-learning-derived brain-aging biomarker between participants with low-and high-impact knee pain. Considering this, we examined whether brain aging was associated with self-reported sleep and pain measures, and whether brain aging mediated the relationship between sleep problems and knee pain. Exploratory Spearman and Pearson partial correlations, controlling for age, sex, race and study site, showed a significant association of brain aging with sleep related impairment and self-reported pain measures. Moreover, mediation analysis showed that brain aging significantly mediated the effect of sleep related impairment on clinical pain and physical symptoms. Our findings extend our prior work demonstrating advanced brain aging among individuals with chronic pain and the mediating role of brain-aging on the association between sleep and pain severity. Future longitudinal studies are needed to further understand whether the brain can be a therapeutic target to reverse the possible effect of sleep problems on chronic pain
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