Concentration of alkanes in the atmosphere
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The dataset contains a variety of atmospheric measurements including time series of air temperature, wind speed and direction, precipitation, irradiance and humidity. A comprehensive atmospheric sampling programme provided measurements of atmospheric particulates, aerosols and gases, including hydrocarbons, nitrogen, oxygen, ozone and sulphur species, carbon monoxide, carbon dioxide, and nitrous and hydrochloric acids. Additional measurements of photolysis rates and ion and radical concentrations were also collected. The data were collected from the vicinity of the north Norfolk coast between 1994 and 1997. The bulk of the data were collected during two field campaigns in the winter (October/November) of 1994 and the summer (May/June) of 1995. During these campaigns data were collected continuously from the University of East Anglia (UEA) Atmospheric Observatory at Weybourne on the north Norfolk coast. The widest range of parameters is available for this station. An instrumented vessel (MV Guardian) was stationed offshore to provide a second sampling site to allow changes in a given air mass to be monitored. The Imperial College London Jetstream Research aircraft made one flight during each campaign to provide a link between the two surface stations and four additional flights in 1996 and 1997. The River-Atmosphere-Coast Study (RACS) was the component of the LOIS programme looking at processes from the river catchment into the coastal sea. Professor John Plane from the Environmental Sciences Department at UEA was the scientific co-ordinator of this sub-project of LOIS. The data are held by BODC as a series of ASCII data files conforming to the NASA AMES 1001 format together with a PDF document that describes the data set.
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The dataset comprises concentration of gas hydrates beneath the seabed, in the water column and, atmosphere along with the topography of the sea floor. Data were collected in the Arctic Ocean off the NorthWestern coast of Svalbard across the continental margin between 78 and 80 North and 4 and 11 East. The data were collected during cruise JR211 which, over two legs, took place between 23rd August 2008 and 24th September 2008. Geophysical and geological techniques were used to detect methane hydrate beneath the seafloor and to investigate features trough which methane escapes to the seafloor. The seabed was imaged and mapped using a multibeam sonar (Simrad EM120), an echosounder (Simrad EK60), TOBI deep-towed sidescan sonar (30 kHz), widescan sidescan sonar (100 and 350 kHz). The sedimentary layers and geological structures beneath the seabed were imaged with the 7 kHz profiler in TOBI, a TOPAS sub-bottom acoustic profiler and multichannel seismic reflaction (96 channels with 6.25 m group spacing) using two air guns in true GI mode 45/105 cu.in. More accurate information on seismic velocity was obtained by deploying ocean-bottom seismometers on the seabed which contained 3 Sercel L-28 4.5 Hz geophones and a High Tech HTI-90-U hydrophone. Sediment samples were obtained using a piston corer, a gravity corer and, a box corer. Water chemistry was measured from discrete samples taken from bottles attached to the conductivity-temperature-depth (CTD) sensor package and continuously from the ship's seawater supply. Methane concentration was measured on-board using a headspace technique. Air samples were collected at 12 hour intervals. Sampling occurred on the Navigation Bridge deck and the side of the ship upwind of the ships emissions was chosen each time. Additional samples were also collected close to the ship's funnel, to check for contamination, and from the gas released by the cores when in an inert atmosphere (N2). Analysis of methane mixing ratio is performed by Gas Chromatography - Flame Ionisation Detector (GC-FID) and the stable carbon isotopic composition of methane is analysed using a continuous flow Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) system. Almost half of the Earth's carbon is stored in gas hydrates and related shallow gas deposits. Numerical models predict that this reservoir is highly mobile and that escaping gas has a significant potential to accelerate climate change releasing as much as 2000 Gt of methane over a short period of time. As methane is a potent greenhouse gas it would course further global warming. Arctic gas hydrates are most vulnerable to future climate change because (1) it is predicted that temperatures will increase faster in the Arctic than in low latitudes (2) the intercept of the gas hydrate stability zone with the seabed is within the reach of fast warming surface waters and (3) the water column above the vulnerable zone of gas hydrates is smaller than in warmer oceans facilitating more efficient transport of greenhouse gases to the atmosphere. This information will allow a detailed assessment of the mobility of Arctic gas hydrates and it will significantly decrease the uncertainties involved in climate modelling. The data were collected by the National Oceanographic Centre, Southampton with Professor Tim Minshull as the principal scientist on-board.
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The dataset comprises a wide range of physical and biogeochemical oceanographic and atmospheric parameters, plus additional biological measurements and observations. Hydrographic parameters include temperature, salinity, current velocities, fluorescence and attenuance, while biogeochemical and biological analyses of water samples provided measurements of dissolved gases, hydrocarbons, sulphur species, dissolved organic carbon (DOC), halocarbons, nutrients, pigments, bacteria, phytoplankton and zooplankton. Bird identification and cetacean abundance studies were also undertaken, as were tracer release experiments using both inert chemical (sulphur hexafluoride, SF6) and bacterial (Bacillus globigii) tracers. Meteorological data were also collected, including concentrations of various chemicals, supplemented by standard measurements of air temperature, pressure, irradiance, humidity and wind velocities. The data were collected in the North Atlantic Ocean and North Sea between 1996 and 1998, as follows: Eastern Atlantic off the coast of Ireland (June-July 1996 and May 1997); southern North Sea (October-November 1996); and North Eastern Atlantic between the UK and Iceland (June-July 1998). The data were collected during four cruises (RRS Challenger CH127, CH129, CH133 and RRS Discovery D234) using a variety of equipment, including instrumentation deployed at sampling stations (e.g. conductivity-temperature-depth (CTD) profilers) and underway sensors that ran throughout each cruise, yielding continuous measurements of both hydrographic and meteorological parameters. Discrete air and water samplers were also used to measure atmospheric and hydrographic parameters throughout each cruise. The data collection periods were associated with individual ACOSE air-sea exchange experiments: two Eastern Atlantic Experiments (EAE96 and EAE97); ASGAMAGE in the southern North Sea; and the North Atlantic Experiment, NAE. ACSOE was a 5-year UK NERC Thematic Research Programme investigating the chemistry of the lower atmosphere (0 - 12 km) over the oceans. The Marine Aerosol and Gas Exchange (MAGE) study group was the only component of the ACSOE Project that included measurements in the marine environment. ACSOE data management was a shared responsibility between the British Atmospheric Data Centre (BADC) and the British Oceanographic Data Centre (BODC). BODC handled the management of ship data as well as all other data collected in the water column during the ACSOE/MAGE cruises. BODC assisted in the onboard collection and subsequent working up of ship data, and assembled all marine data in BODC's relational database carrying out quality control and data processing as required. ACSOE was led by Prof. Stuart Penkett of the University of East Anglia and cruise principle scientists included representatives of the University of Newcastle Upon Tyne, and the University of East Anglia.
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The dataset comprises hydrographic data, including salinity, temperature, depth, dissolved oxygen, transmittance (for suspended sediment), chlorophyll, irradiance, and current velocities. Both oceanographic and benthic measurements of nutrients (nitrate, nitrite, silicate, phosphate and ammonium), phytoplankton and zooplankton abundance, dissolved and particulate trace metals, primary and bacterial production, sulphur compounds and halocarbons were collected, as well as atmospheric physical and chemical measurements. The data were collected in the North Sea between August 1988 and October 1990 over a series of 38 cruises on RRS Challenger. Oceanographic measurements were taken using hydrographic profilers, moored instruments and shipboard underway systems. Underway meteorological data were also collected in addition to a comprehensive atmospheric sampling programme. Both continuous and discrete water samples were collected, providing biogeochemical and biological data. These were supplemented by net hauls. Benthic processes were investigated with sediment cores taken on eight survey cruises at six sites of varied character, three being in the area of summer stratification. Water and benthic sample analyses were supplemented by results of seabed and shipboard incubation experiments. The North Sea Project evolved from a NERC review of shelf seas research, which identified the need for a concerted multidisciplinary study of circulation, transport and production. The Proudman Oceanographic Laboratory (POL), now the National Oceanography Centre (NOC) hosted the project. It involved over 200 scientists and support staff from the Natural Environment Research Council (NERC), the Ministry of Agriculture, Fisheries and Food (MAFF - now DEFRA) and other academic institutes. The data are held at the British Oceanographic Data Centre and are available on CD-ROM.
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The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing well over 1000 parameters. There are data from over 1000 conductivity-temperature-depth (CTD)/rosette stations, over 440 core profiles, over 180 sediment trap samples, over 140 net hauls and much, much more. The primary study area was a box extending to the base of the slope from Vigo to Cap Finistere. However, data are included from both further offshore (filament tracking) and from the Portuguese Margin. Measurements were taken from November 1996 to October 1999 during 33 cruise legs, involving research vessels from seven nations. Data were collected using a variety of equipment and techniques, including expendable bathythermographs (XBTs), turbulence probes, CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and a comprehensive water sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and phosphate uptake experiments are also included in the dataset, as are bathymetric data from multibeam (swath) surveys, coastal upwelling measurements and data from moored instruments and benthic landers. The dataset also includes imagery from satellites, seabed photography and X-ray photographs of core samples. The aim of the project was study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. The project brought together over 100 scientists from 40 research centres and universities throughout Europe. The British Oceanographic Data Centre (BODC) is assembling the data sets collected during OMEX II into its project database system and the data set is also available on CD-ROM.
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The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing over 1000 parameters. There are data from over 1650 conductivity-temperature-depth (CTD)/rosette stations, over 300 core profiles, over 370 sediment trap samples and much, much more. Most of this effort was directed at the region of the east Atlantic margin between La Chapelle Bank and the Goban Spur (between France and Ireland). In addition, there were two secondary areas of interest: the Norwegian Shelf Break just off Tromso and the Iberian Margin, either off Vigo or in the vicinity of the Tagus estuary. Measurements were collected from April 1993 until the end of December 1995 during 55 research cruise legs. Data were collected using a variety of equipment and techniques, including expendable bathythermography (XBTs), CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and comprehensive water and air sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and trace metal experiments are also included in the dataset, as are bathymetric data from the British Oceanographic Data Centre (BODC) GEBCO digital Atlas, air-sea flux measurements and data from moored instruments and benthic landers that were deployed for periods from a few weeks to a year. The dataset also includes imagery from satellites, water column and seabed photography, scanning electron micrographs and X-ray photographs. FORTRAN source code for biogeochemical models developed during OMEX I is also included. The aim of the project was to study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. OMEX I involved scientists from 30 institutions in 10 countries. BODC is assembling the data sets collected during OMEX I into its database system and the data are also available on CD-ROM.