RRS Discovery Cruise D359, 17 Dec 2010-14 Jan 2011. RAPID moorings cruise report

This cruise report covers scientific operations conducted during RRS Discovery Cruise D359. Cruise D359 departed from São Antonio, Cape Verde on Friday 17th December 2010 arriving Santa Cruz de Tenerife Friday 14th December 2011.The purpose of the cruise was the refurbishment of an array of moorings on the mid-­Atlantic Ridge and off the Moroccan Coast at a nominal latitude of 26.5°N. The moorings are part of a purposeful Atlantic wide mooring array for monitoring the Atlantic Meridional Overturning Circulation and Heat Flux. The array is a joint UK/US programme and is known as the RAPID-­?WATCH/MOCHA array. Information and data from the project can be found on the web site hosted by the National Oceanography Centre Southampton http://www.noc.soton.ac.uk/rapidmoc and also from the British Oceanographic Data Centre http://www.bodc.ac.uk.The RAPID transatlantic array consists of 24 moorings of which 21 are maintained by the UK, and 20 bottom landers of which 16 are maintained by the UK. The moorings are primarily instrumented with self logging instruments measuring conductivity, temperature and pressure. Direct measurements of currents are made in the shallow and deep western boundary currents. The bottom landers are instrumented with bottom pressure recorders (also known as tide gauges), measuring the weight of water above the instrument.The RAPID naming convention for moorings is Western Boundary (WB), Eastern Boundary (EB) and Mid-­Atlantic Ridge (MAR) indicating the general sub-­regions of the array. Numbering increments from west to east. An L in the name indicates a bottom lander, M indicates a mini-­mooring with only one instrument, H indicates a mooring on the continental slope. During D359 we recovered: MAR0, MAR1L4, MAR1, MAR2, MAR3, MAR3L4, EB1, EB1L7, EBHi, EBH1, EBH1L7, EBH2, EBH3, EBH4, EBP2, EBH5, EBM5. We did not recover EBM1, EBM4, EBM6, EBH1 and MAR3. We deployed: MAR0, MAR1L7, MAR1, MAR2, MAR3, MAR3L6, EB1, EB1L7, EBHi, EBH1, EBH1L8, EBH2, EBH3, EBH4, EBP2, EBH5. A sediment trap mooring NOGST was also recovered and redeployed for the Ocean Biogeochemistry and Ecosystems Group at the NOCS.CTD stations were conducted at convenient times throughout the cruise for purposes of providing pre and post deployment calibrations for mooring instrumentation and for testing mooring releases prior to deployment.Shipboard underway measurements were systematically logged, processed and calibrated, including: waves (spectra of energy and significant wave height), surface meteorology (air pressure, temperature, wind speed and direction and radiation (total incident and photosynthetically active), 6m-­depth sea temperatures and salinities, water depth, navigation (differential GPS measurements feeding two independent and different receivers, heading, pitch and roll from a four antenna Ashtec ADU5 receiver, gyro heading and ships speed relative to the water using an electro-­magnetic log). Water velocity profiles from 15m to approximately 500m depth were obtained using a ship mounted 75 kHz acoustic Doppler current profiler. Sea-­water samples from CTD stations and of the sea-­surface were obtained for calibration and analysed on a salinometer referencing these samples against standard sea water. For velocity data (wind and currents) measured relative to the ship considerable effort was made to obtain the best possible earth-­referenced velocities.Four APEX argo floats supplied by the Met Office were deployed at pre-­assigned locations, filling gaps in the network

RRS Discovery Cruise 242, 07 Sep-06 Oct 1999. Atlantic - Norwegian Exchanges

This report describes RRS Discovery cruise 242 from 07 September to 06 October 1999. The cruise title is Atlantic - Norwegian Exchanges. There are two distinct parts to this experiment with closely related objectives. The first is to measure the pathways and flux of warm, upper ocean water northward through the Iceland Basin and Rockall Trough to high latitudes. The second is to measure the returning flux of cold, deep water that flows through the Faroe Bank Channel into the North Atlantic. A full depth hydrographic section was occupied between Scotland and Iceland, repeating the frequently occupied Rockall Trough section (occupied 36 times between March 1975 and January 1996) and it's recent extension from Rockall to Iceland (occupied in 1997, 1998 and now in 1999). A second section was occupied from southeast Iceland to Lousy Bank (occupied in 1962,1990 and 1996). These two sections comprised CTD/LADCP stations with discrete vertical samples for salinity, oxygen, silicate, nitrate and phosphate. Horizontal station spacing was ~30 km in the Iceland Basin but much closer over steep bathymetry and in the Rockall Trough. Ancilliary measurements of transmittance and reversing temperature and salinity were also made. Shipbourne observations were made throughout the cruise and comprised ADCP, navigation, meteorology, waves, echosounding and surface temperature and salinity. These two sections were designed to measure the pathways of the northward flow through the Iceland Basin and Rockall Trough. Differences to earlier occupations will show the time variability of these flows. In the Faroe Bank Channel and on the Iceland Ridge eight sections were occupied (some repeats) to examine the cold outflow into the North Atlantic. These sections were made in the Faroe Bank Channel and downstream of the sill, at a horizontal separation of between 15 km and 40 km. Five of these were standard CTD/LADCP sections with chemistry observations. Three sections were also occupied using the BRIDGET deep tow vehicle. This vehicle carried a CTD and 12 bottle rosette for water samples as well as some auxiliary sensors. The key novelty was the mounting of self-contained downward and upward looking ADCP's. BRIDGET was towed at 100 m off bottom giving cross-stream measurements at high resolution of the velocity structure of the overflow. These sections were taken in and just downstream from the Faroe Bank Channel sill. We will examine the initial adjustment of the overflow and with contemporaneous observations made in the Faroe Shetland (Fisheries Research Services, Aberdeen) the role of hydraulic control at the Faroe Bank Channel sill. The two sections in the Iceland Basin cross the overflow 360 km and 660 km downstream from the source defining the far field location and properties of the overflow. A short section of XBT observations was made along the Wyville-Thomson Ridge to measure the temperature at two saddle points where it is occasionally observed that cold Faroe Bank Channel water passes into the Rockall Trough

RRS James Clark Ross Cruise JR55, 21 Nov-14 Dec 2000. Drake Passage repeat hydrography: WOCE Southern Section 1b – Burdwood Bank to Elephant Island

This report describes the sixth repeat hydrography section across Drake Passage, first established during the International World Ocean Circulation Experiment. Through continuation of this time series the nature of the interannual variability in the location and properties of the ACC at this choke point between South America and the Antarctic Peninsula can be determined. Across the 644km section from Burdwood Bank to Elephant Island, thirty-one CTD/LADCP stations (including one test station) were made on the southbound journey with a maximum station spacing of 33km. Water samples were drawn for salinity analysis and CTD conductivity calibration. The underway measurements included: Vessel Mounted Acoustic Doppler Current Profiler, measuring currents to depths of 300m beneath the ship, navigation, sea surface temperatures recorded by thermosalinograph, meteorology logged via the oceanlogger system and Simrad echo sounder determining water depths. CTD station 32 was at the Rothera time series (RaTs) site just off Rothera Pier, carried out primarily for collected water samples for nutrient analysis back at SOC.On the northbound crossing of Drake Passage, to the west of the southbound section, an extra two full depth CTD/LADCP stations were made to test CTD DEEP03. XBTs were deployed at two hourly intervals and underway data logged. This report was compiled by Louise M. Duncan

Progressing social prescribing with a focus on process of connection : evidence-informed guidance for robust evaluation and evidence synthesis

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Multidecadal variability of potential temperature, salinity, and transport in the eastern subpolar North Atlantic

The Extended Ellett Line (EEL) hydrographic section extends from Scotland to Iceland crossing the Rockall Trough, Hatton-Rockall Basin and Iceland Basin. With 61 full-depth stations at a horizontal resolution of 10 to 50 km, the EEL samples the upper limb of the Atlantic Meridional Overturning Circulation flowing across the Iceland-Scotland Ridge into the Nordic Seas. The Rockall Trough has been sampled nearly four times per year from 1975 to 1996, and the full section annually since 1996. The EEL is an exceptionally long timeseries of deep-ocean temperatures and salinities. This study extends prior work in the Rockall Trough, and examines for the first time 18 year records in the Iceland and Hatton-Rockall Basins. We quantify errors in the timeseries from two sources: observational errors and aliasing. The data quality and annual sampling are suitable for observing interannual to decadal variability because the variability exceeds our error estimates. The upper waters of all 3 basins are cooler/fresher from 1997 to 2001, warmer/more saline 2001 to 2006, and cooler/fresher from 2006 to 2014. A reference level for geostrophic shear is developed heuristically and by comparison with sea-surface altimetry. The mean northward transport in the upper waters is 6.7±3.7 Sv and there is a 6.1±2.5 Sv southward flow below the thermocline. Although the magnitude of the Iceland Basin overturning circulation (4.3±1.9 Sv) is greater than in the Rockall Trough (3.0±3.7 Sv), the variability is greater in the Rockall Trough. We discuss the results in the context of our understanding of drivers of variability

The Blackbody Radiation Spectrum Follows from Zero-Point Radiation and the Structure of Relativistic Spacetime in Classical Physics

The analysis of this article is entirely within classical physics. Any attempt to describe nature within classical physics requires the presence of Lorentz-invariant classical electromagnetic zero-point radiation so as to account for the Casimir forces between parallel conducting plates at low temperatures. Furthermore, conformal symmetry carries solutions of Maxwell's equations into solutions. In an inertial frame, conformal symmetry leaves zero-point radiation invariant and does not connect it to non-zero-temperature; time-dilating conformal transformations carry the Lorentz-invariant zero-point radiation spectrum into zero-point radiation and carry the thermal radiation spectrum at non-zero temperature into thermal radiation at a different non-zero-temperature. However, in a non-inertial frame, a time-dilating conformal transformation carries classical zero-point radiation into thermal radiation at a finite non-zero-temperature. By taking the no-acceleration limit, one can obtain the Planck radiation spectrum for blackbody radiation in an inertial frame from the thermal radiation spectrum in an accelerating frame. Here this connection between zero-point radiation and thermal radiation is illustrated for a scalar radiation field in a Rindler frame undergoing relativistic uniform proper acceleration through flat spacetime in two spacetime dimensions. The analysis indicates that the Planck radiation spectrum for thermal radiation follows from zero-point radiation and the structure of relativistic spacetime in classical physics.Comment: 21 page

Computing gravitational waves from slightly nonspherical stellar collapse to black hole: Odd-parity perturbation

Nonspherical stellar collapse to a black hole is one of the most promising gravitational wave sources for gravitational wave detectors. We numerically study gravitational waves from a slightly nonspherical stellar collapse to a black hole in linearized Einstein theory. We adopt a spherically collapsing star as the zeroth-order solution and gravitational waves are computed using perturbation theory on the spherical background. In this paper we focus on the perturbation of odd-parity modes. Using the polytropic equations of state with polytropic indices $n_p=1$ and 3, we qualitatively study gravitational waves emitted during the collapse of neutron stars and supermassive stars to black holes from a marginally stable equilibrium configuration. Since the matter perturbation profiles can be chosen arbitrarily, we provide a few types for them. For $n_p=1$, the gravitational waveforms are mainly characterized by a black hole quasinormal mode ringing, irrespective of perturbation profiles given initially. However, for $n_p=3$, the waveforms depend strongly on the initial perturbation profiles. In other words, the gravitational waveforms strongly depend on the stellar configuration and, in turn, on the ad hoc choice of the functional form of the perturbation in the case of supermassive stars.Comment: 31 pages, accepted for publication in Phys. Rev. D, typos and minor errors correcte

SMAD6 variants in craniosynostosis: genotype and phenotype evaluation

Purpose: Enrichment of heterozygous missense and truncating SMAD6 variants was previously reported in nonsyndromic sagittal and metopic synostosis, and interaction of SMAD6 variants with a common polymorphism near BMP2 (rs1884302) was proposed to contribute to inconsistent penetrance. We determined the occurrence of SMAD6 variants in all types of craniosynostosis, evaluated the impact of different missense variants on SMAD6 function, and tested independently whether rs1884302 genotype significantl