The hydrography and circulation of the upper 1200 meters in the tropical North Atlantic during 1982-91

We assemble a collection of 7591 conductivity-temperature-depth stations in the tropical Atlantic between 5S and 20N for the period 1982–1991 using data from the Soviet SECTIONS program enhanced by contributions primarily from the WESTRAX and FOCAL/SEQUAL programs. Most of the stations are west of 30W, forming a series of 21 surveys. In addition there were five multi-ship basinwide surveys, each taking 1.5–3 months to complete. The quality of the SECTIONS data is discussed and comparisons between the data sets are shown. Within the pycnocline, southern water is distinguished by salinity that is 0.3 psu lower than its northern counterpart at the same density. This difference allows us to distinguish the origin of pycnocline water. Based on this information together with geostrophic analysis we confirm that much of the water transported across the equator in the North Brazil Current retroflects eastward south of 8N. In summer and fall the water of the North Brazil Current merges with the water of the North Equatorial Current to form the North Equatorial Countercurrent, whose axis shifts southward with depth. East of 35W part of the mass transport in the Countercurrent is lost to the equatorial zone, while the rest continues eastward. During winter and spring eastward currents are found in two latitude bands, a surface current between 5–10N and a weaker current south of 5N confined to the thermocline. This latter North Equatorial Undercurrent has no surface expression in winter. During the summer and fall the northern boundary of Southern Hemisphere water at pycnocline depths is given by the North Equatorial Countercurrent. During the rest of the year the northern boundary of Southern Hemisphere water only penetrates to the edge of the weaker North Equatorial Undercurrent south of 5N. The availability of ten years of data allows us to examine aspects of year-to-year variability. Among these results the data set reveals strong meandering of the North Equatorial Countercurrent between 42W and 35W during the summer of 1987. The meandering also appears in contemporaneous Geosat altimetry. Another unusual feature occurred in the summer 1986 when there was a strong thermocline current transporting water northward at the rate of 26 Sv. Water mass analysis shows that this current was the result of a pressure gradient set up by an intrusion of warm low-salinity water from the Southern Hemisphere. The fact that this high transport occurred in the interior ocean suggests that interior flows must be monitored during any attempt to observe meridional transports of mass or heat

Interannual to Decadal Variability of Atlantic Water in the Nordic and Adjacent Seas

Warm salty Atlantic Water is the main source water for the Arctic Ocean and thus plays an important role in the mass and heat budget of the Arctic. This study explores interannual to decadal variability of Atlantic Water properties in the Nordic Seas area where Atlantic Water enters the Arctic, based on a reexamination of the historical hydrographic record for the years 1950-2009, obtained by combining multiple data sets. The analysis shows a succession of four multi-year warm events where temperature anomalies at 100m depth exceed 0.4oC, and three cold events. Three of the four warm events lasted 3-4 years, while the fourth began in 1999 and persists at least through 2009. This most recent warm event is anomalous in other ways as well, being the strongest, having the broadest geographic extent, being surface-intensified, and occurring under exceptional meteorological conditions. Three of the four warm events were accompanied by elevated salinities consistent with enhanced ocean transport into the Nordic Seas, with the exception of the event spanning July 1989-July 1993. Of the three cold events, two lasted for four years, while the third lasted for nearly 14 years. Two of the three cold events are associated with reduced salinities, but the cold event of the 1960s had elevated salinities. The relationship of these events to meteorological conditions is examined. The results show that local surface heat flux variations act in some cases to reinforce the anomalies, but are too weak to be the sole cause

An assessment of the long-term effects of three phosphorus fertiliser regimes on soil phosphorus and sward condition.

End of Project ReportA grazing trial using beef animals (mean weight 260 kg) was used to determine optimum soil phosphorus levels for dry stock farming. · The trial commenced in 1968. There were three fertiliser P treatments, 0, 15 and 30 kg P/ha applied annually. There were two stocking rates, 3300 and 2400 kg liveweight at turn out, respectively. Animals were rotationally grazed around six paddocks per treatment and stocking rates were reduced in June and September to match feed supply. The trial continued until 1998. ¸ Nitrogen was applied at a rate of 220 kg/ha per year to all treatments. ¹ Liveweight gains/ha/year were monitored annually. Soil P levels were monitored by sampling to 10 cm depth. º The distribution of phosphorus in the soil was recorded by analysing P levels at various depths from 0-2 mm to 100 cm. Botanical composition was recorded at the commencement of the trial and again in 1997. Phosphorus levels in herbage were also recorded. » An analysis of the liveweight gain data showed that for optimum output a Soil Index of 3 (Morgans P between 6.1 and 10.0 mg/l) is the target Soil P Index. ¼ Phosphorus recovery (as expressed by percentage of P fertiliser recovered in product) in the P30 treatments was low and was better in the P15 treatments. ½ The vast bulk of P accumulated near the surface of the soil, but there was some evidence of movement down the profile in the P30 treatment over a 30 year period. The soil P status influenced both the botanical composition of the sward and the P content in the herbage. The perennial ryegrass content declined on the zero P treatment, while there were no significant differences between the P15 and P30 treatments. The P concentration in the herbage in the zero P treatments were not sufficient for healthy growth of plants or animals.E u ropean Union Structural Funding (EAGGF

Phosphorus loss from soil to water.

End of Project ReportThe work described under this project covers field work on phosphorus(P) loss from soil to water under field conditions. In addition two International Workshops on P loss to water, held in Ireland in 1995 and 1998, are also covered under this project. The results indicate that P loss to water is a complex process and it is influenced by a number of factors, including hydrology of the soil, rates and timing of P application and soil P levels. Most work on this subject indicates that there is a positive relationship between soil test P levels and P loss to water. There is need for further work to establish the relative contribution of the different variables involved in P loss from soil to water for different soils and farming conditions. This should help provide answers to the most sustainable methods to minimise losses of P to water and ensure that agricultural production is compatible with good water quality.European Union Structural Funds (EAGGF

Reading with the Tongue: Individual Differences Affect the Perception of Ambiguous Stimuli with the BrainPort

There is an increasing interest in non-visual interfaces for HCI to take advantage of the information processing capability of the other sensory modalities. The BrainPort is a vision-to-tactile sensory substitution device that conveys information through electro-stimulation on the tongue. As the tongue is a horizontal surface, it makes for an interesting platform to study the brain’s representation of space. But which way is up on the tongue? We provided participants with perceptually ambiguous stimuli and measured how often different perspectives were adopted; furthermore, whether camera orientation and gender had an effect. Additionally, we examined whether personality (trait extraversion and openness) could predict the perspective taken. We found that self-centered perspectives were predominantly adopted, and that trait openness may predict perspective. This research demonstrates how individual differences can affect the usability of sensory substitution devices, and highlights the need for flexible and customisable interfaces

Developments in fuel cell technologies in the transport sector

The demand for clean power source which can be used to run the various types of vehicles on the road is increasing on a daily basis due to the fact that high emissions released from internal combustion engine play a significant role in air pollution and climate change. Fuel cell devices, particularly Proton Exchange Membrane (PEM) type, are strong candidates to replace the internal combustion engines in the transport industry. The PEMFC technology still has many challenges including high cost, low durability and hydrogen storage problems which limit the wide-world commercialization of this technology. In this paper, the fuel cell cost, durability and performances challenges which are associated with using of fuel cell technology for transport applications are detailed and reviewed. Recent developments that deal with the proposed challenges are reported. Furthermore, problems of hydrogen infrastructure and hydrogen storage in the fuel cell vehicle are discussed

Satellite Evidence of Hurricane-Induced Phytoplankton Blooms in an Oceanic Desert

The physical effects of hurricanes include deepening of the mixed layer and decreasing of the sea surface temperature in response to entrainment, curl-induced upwelling, and increased upper ocean cooling. However, the biological effects of hurricanes remain relatively unexplored. In this paper, we examine the passages of 13 hurricanes through the Sargasso Sea region of the North Atlantic during the years 1998 through 2001. Remotely sensed ocean color shows increased concentrations of surface chlorophyll within the cool wakes of the hurricanes, apparently in response to the injection of nutrients and/or biogenic pigments into the oligotrophic surface waters. This increase in post-storm surface chlorophyll concentration usually lasted 2-3 weeks before it returned to its nominal pre-hurricane level

Ex-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environment

Metallic-based bipolar plates exhibit several advantages over graphite-based plates, including higher strength, lower manufacturing cost and better electrical conductivity. However, poor corrosion resistance and high interfacial contact resistance (ICR) are major challenges for metallic bipolar plates used in proton exchange membrane (PEM) fuel cells. Corrosion of metallic parts in PEM fuel cells not only increases the interfacial contact resistance but it can also decrease the proton conductivity of the Membrane Electrode Assembly (MEA), due to catalyst poisoning phenomena caused by corrosive products. In this paper, a composite coating of polytetrafluoroethylene (PTFE) was deposited on stainless steel alloys (SS304, SS316L) and Titanium (G-T2) via a CoBlast™ process. Corrosion resistance of the coated and uncoated metals in a simulated PEM fuel cell environment of 0.5 M H2SO4 + 2 ppm HF at 70 °C was evaluated using potentiodynamic polarisation. ICR between the selected metals and carbon paper was measured and used as an indicator of surface conductivity. Scanning Electron Microscopy (SEM), 3D microscopy, Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD), and contact angle measurements were used to characterise the samples. The results showed that the PTFE coating improved the hydrophobicity and corrosion resistance but increased the ICR of the coated metals due to the unconductive nature of such coating. Thus, it was concluded that it is not fully feasible to use the PTFE alone for coating metals for fuel cell applications and a hybrid coating consisting of PTFE and a conductive material is needed to improve surface conductivity.Enterprise Irelan