Concentrations of dissolved and atmospheric nitrous oxide, N2O, were measured in the austral spring of 1992 in the Drake Passage and Bellingshausen Sea as part of the United Kingdom Joint Global Ocean Flux Study expedition to the Southern Ocean. The measured atmospheric mixing ratio was 313 +/- 5 parts per billion by volume, in agreement with the hemispherically corrected global mean. In the Drake Passage, surface N2O saturations were generally very close to atmospheric equilibrium, 99.7 +/- 3%, although several anomalous points were associated with the presence of frontal and eddy-like features within the Antarctic Polar Frontal Zone and at the Continental Water Boundary. Further to the south, a series of oceanographic stations and two surface transects along the 85 degrees W meridian between 65.28 degrees S and 70.32 degrees S revealed a transition from undersaturated conditions in open water to oversaturated conditions in the marginal ice zone, in the upper mixed layer (75-100 m). These observations reflect upwelling of Circumpolar Deep Water at approximately 70 degrees S, resulting in the accumulation of N2O under the winter sea ice and its subsequent release to the atmosphere following the ice retreat. Sea-air N2O fluxes were estimated from the product of the surface N2O anomaly and the modelled gas transfer coefficients of Liss and Merlivat [1986] and Wanninkhof [1992] to find a maximum rate of +3.1 micromole N2O m-2 d -1. North of the upwelling region, Antarctic Surface Water formed from the mixing of surface waters and ice melt was moderately depleted in N2O with respect to the atmosphere, a minimum 90% of saturation. This sink area was estimated to extend between 65.28 degrees S and 69.57 degrees S with a mean sea-air flux of between -0.6 +/- 0.4 and -0.9 +/- 0.7 micromole N2O m-2 d-1. The region studied at 85 degrees W (65.28 degrees S to 70.32 degrees S) revealed source and sink areas which were largely determined by the changing physical hydrography, so that overall there was a small net negative flux of between -0.06 +/- 0.9 and -0.09 +/- 1.4 micromole N2O m-2 d-1. Funding: The work was supported by NERC funding to the Plymouth Marine Laboratory, the British Antarctic Survey and from the U.K. Biogeochemical Flux Study (BOFS).

These data include greenhouse gas concentrations and physio-chemical water properties for the Clyde estuary in Scotland to support understanding of the GHG sources and sinks and their associated mechanisms in a highly stratified, temperate urban estuary. These measurements look at the changes in GHG along the Clyde estuary taking measurements from land to sea down the estuary on the ebb tide at both the surface and bed so the impact of location, river flow, wastewater treatment outflows and stratifications can be understood. Full details about this dataset can be found at https://doi.org/10.5285/a22b495e-b2cd-43cd-95b7-8712b64dc0da

The data pertains to a single time point 'snapshot' spatial sampling of site characteristics, soil parameters and soil greenhouse gas emissions for two sites (Extensive and Intensive). The extensively managed site ('Extensive'; 240-340 m above sea level; a.s.l.) consisted of an 11.5 ha semi-improved, sheep-grazed pasture at Bangor University's Henfaes Research Station, Abergwyngregyn, North Wales (53°13'13''N, 4°0'34''W). The intensively managed site ('Intensive'; on average 160 m a.s.l.) was a 1.78 ha sheep-grazed pasture located in south-west England, at the North Wyke Farm Platform (NWFP), Rothamsted Research, Okehampton, Devon (50°46'10''N, 30°54'05''W). At the Extensive site soil and gas sampling was conducted on 30th November 2016. At the Intensive site soil and gas sampling was conducted on 1st August 2016. The data contains: site characteristics including elevation, slope, compound topographic index, vegetation type or manure application, and sample point grid references; soil parameters including soil bulk density, soil percentage water-filled pore space, soil moisture, soil organic matter contents, soil pH, soil nitrate nitrogen concentration, soil ammonium nitrogen concentration, soil percentage total carbon contents, soil percentage total nitrogen contents, and carbon to nitrogen content ratio; and soil greenhouse gas flux data for nitrous oxide, carbon dioxide and methane. The study was conducted as a wider part of the NERC funded Uplands-N2O project and BBSRC-supported Rothamsted Research, North Wyke Farm Platform (Grant Nos: NE/M015351/1, NE/M013847/1, NE/M013154/1, BBS/E/C/000J0100, BBS/E/C/000I0320, BBS/E/C/000I0330). Quantifying the spatial and variability of the drivers of greenhouse gas emissions and their interactions in grazing systems is critical to improve our understanding of nitrous oxide, carbon dioxide and methane fluxes, enabling better estimates of aggregated greenhouse gas emissions and associated uncertainties at the landscape scale. Full details about this dataset can be found at https://doi.org/10.5285/f3118fa8-6bec-488b-9713-2415912b8b9e

The dataset comprises nitrous oxide (N2O) flux data, collected from static chambers as part of a study to determine how land management affected nitrogen cycling by nitrifiers and denitrifiers in an upland agricultural grassland soil and to determine the effects of changing environmental conditions on nitric and nitrous oxide production and emission as a result of land management. Data were collected during a project funded under the NERC Soil Biodiversity Programme, established in 1999 and centred upon the intensive study of a large field experiment located at the Macaulay Land Use Research Institute (now the James Hutton Institute) farm at Sourhope in the Scottish Borders (Grid reference: NT8545019630). During the experiment, the site was monitored to assess changes in above-ground biomass production (productivity), species composition and relative abundance (diversity). Full details about this dataset can be found at https://doi.org/10.5285/46b23af7-0f63-4416-ad71-c08ee028c3b2

This dataset contains concentrations of dissolved organic carbon, dissolved inorganic carbon, nutrients and concentrations of greenhouse gases CO2, CH4 and N2O from nine sites across the River Tay catchment. Water was sampled on a monthly basis between February 2009 and December 2010. The locations of sampling sites were based on existing flow gauging and water sampling sites of the Scottish Environment Protection Agency (SEPA). Full details about this dataset can be found at https://doi.org/10.5285/a61da7da-b7ef-40b7-a324-c3711ef81207

The dataset contains greenhouse gas fluxes (N2O, CO2 and CH4) following artificial and real sheep urine applied to organic soils within the Carneddau mountain range (556 m a.s.l.) in Snowdonia National Park, North Wales, UK. The study was conducted across two contrasting seasons (summer and autumn). Soil greenhouse gas emission data was collected using a combination of automated chambers and manually sampled chambers, with gas samples analysed via gas chromatography. Supporting data include characterisation of the soil properties at each site, meteorological data, soil moisture and soil chemistry on a time-series following treatment application. The data were used to calculate sheep urine patch N2O-N emission factors, to improve estimates of greenhouse gas emissions from sheep urine deposited to extensively grazed montane agroecosystems. Full details about this dataset can be found at https://doi.org/10.5285/01811fce-1e0f-43be-8649-336b5c51d6cf

The dataset contains instantaneous fluxes of carbon dioxide, methane and nitrous oxide from intact lysimeters in agricultural grasslands in the Hampshire Avon catchment (UK). Manipulations of soil temperature, soil water saturation, additions of nitrogen, phosphorus and of nitrogen and phosphorus were made at three orthogonal experiments in three sub-catchments of contrasting geology (chalk, clay and greensand). Fluxes of carbon dioxide were directly measured continuously during 2014 and 2015 using automated chamber approach, and fluxes of methane and nitrous oxide were measured in 'campaign' mode. Flux measurements consisted of chamber closure for 180 seconds, except when in 'campaign' mode when measurement periods were extended to 300 seconds. Full details about this dataset can be found at https://doi.org/10.5285/8031c2c1-7032-4958-b314-7664d747b988