389 research outputs found
Atmospheric Methane : Comparison Between Methane's Record in 2006–2022 and During Glacial Terminations
Atmospheric methane's rapid growth from late 2006 is unprecedented in the observational record. Assessment of atmospheric methane data attributes a large fraction of this atmospheric growth to increased natural emissions over the tropics, which appear to be responding to changes in anthropogenic climate forcing. Isotopically lighter measurements of (Figure presented.) are consistent with the recent atmospheric methane growth being mainly driven by an increase in emissions from microbial sources, particularly wetlands. The global methane budget is currently in disequilibrium and new inputs are as yet poorly quantified. Although microbial emissions from agriculture and waste sources have increased between 2006 and 2022 by perhaps 35 Tg/yr, with wide uncertainty, approximately another 35–45 Tg/yr of the recent net growth in methane emissions may have been driven by natural biogenic processes, especially wetland feedbacks to climate change. A model comparison shows that recent changes may be comparable or greater in scale and speed than methane's growth and isotopic shift during past glacial/interglacial termination events. It remains possible that methane's current growth is within the range of Holocene variability, but it is also possible that methane's recent growth and isotopic shift may indicate a large-scale reorganization of the natural climate and biosphere is under way
Environmental monitoring : phase 5 final report (April 2019 - March 2020)
This report presents the results and interpretation for Phase 5 of an integrated environmental
monitoring programme that is being undertaken around two proposed shale gas sites in England –
Preston New Road, Lancashire and Kirby Misperton, North Yorkshire. The report should be read
in conjunction with previous reports freely available through the project website1
. These provide
additional background to the project, presentation of earlier results and the rationale for
establishment of the different elements of the monitoring programme
Environmental monitoring : phase 4 final report (April 2018 - March 2019)
This report describes the results of activities carried out as part of the Environmental
Monitoring Project (EMP) led by the British Geological Survey (BGS) in areas around two
shale gas sites in England – Kirby Misperton (Vale of Pickering, North Yorkshire) and Preston
New Road (Fylde, Lancashire). It focuses on the monitoring undertaken during the period April
2018–March 2019 but also considers this in the context of earlier monitoring results that have
been covered in reports for earlier phases of the project (Phases I–IV)
2
.
The EMP project is a multi-partner project involving BGS together with Public Health England
(PHE), University of Birmingham, University of Bristol, University of Manchester, Royal
Holloway University of London (RHUL) and University of York. The work has been enabled
by funding from a combination of the BGS National Capability programme, a grant awarded
by the UK Government’s Department for Business Energy & Industrial Strategy (BEIS) and
additional benefit-in-kind contributions from all partners.
The project comprises the comprehensive monitoring of different environment compartments
and properties at and around the two shale-gas sites. The component parts of the EMP are all
of significance when considering environmental and human health risks associated with shale
gas development. Included are seismicity, ground motion, water (groundwater and surface
water), soil gas, greenhouse gases, air quality, and radon.
The monitoring started before hydraulic fracturing had taken place at the two locations, and so
the results obtained before the initiation of operations at the shale-gas sites represent baseline
conditions. It is important to characterise adequately the baseline conditions so that any future
changes caused by shale gas operations, including hydraulic fracturing, can be identified. This
is also the case for any other new activities that may impact those compartments of the
environment being monitored as part of the project.
In the period October 2018–December 2018, an initial phase of hydraulic fracturing took place
at the Preston New Road (PNR) shale-gas site (shale gas well PNR1-z) in Lancashire. This was
followed by a period of flow testing of the well to assess its performance (to end of January
2019). The project team continued monitoring during these various activities and several
environmental effects were observed. These are summarised below and described in more
detail within the report. The initiation of operations at the shale-gas site signified the end of
baseline monitoring. At the Kirby Misperton site (KMA), approval has not yet been granted
for hydraulic fracturing of the shale gas well (KM8), and so no associated operations have
taken place during the period covered by this report. The effects on air quality arising from the
mobilisation of equipment in anticipation of hydraulic fracturing operations starting was
reported in the Phase III report, and in a recently published paper3
. Following demobilisation of the equipment and its removal from the site, conditions returned to baseline and the on-going
monitoring (reported in this report) is effectively a continuation of baseline monitoring
Ground-Based Mobile Measurements to Track Urban Methane Emissions from Natural Gas in 12 Cities across Eight Countries
Plant growth-promoting rhizobacteria mediate induced systemic resistance in rice against bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae
In vitro effect of pH on resistance of ruminal bacteria to intracellular potassium depletion, and effect of pH and ionophores on ammonia and microbial protein production
Isotopic signatures of methane emissions from tropical fires, agriculture and wetlands: the MOYA and ZWAMPS flights
We report methane isotopologue data from aircraft and ground measurements in Africa and South America. Aircraft campaigns sampled strong methane fluxes over tropical papyrus wetlands in the Nile, Congo and Zambezi basins, herbaceous wetlands in Bolivian southern Amazonia, and over fires in African woodland, cropland and savannah grassland. Measured methane δ13CCH4 isotopic signatures were in the range −55 to −49‰ for emissions from equatorial Nile wetlands and agricultural areas, but widely −60 ± 1‰ from Upper Congo and Zambezi wetlands. Very similar δ13CCH4 signatures were measured over the Amazonian wetlands of NE Bolivia (around −59‰) and the overall δ13CCH4 signature from outer tropical wetlands in the southern Upper Congo and Upper Amazon drainage plotted together was −59 ± 2‰. These results were more negative than expected. For African cattle, δ13CCH4 values were around −60 to −50‰. Isotopic ratios in methane emitted by tropical fires depended on the C3 : C4 ratio of the biomass fuel. In smoke from tropical C3 dry forest fires in Senegal, δ13CCH4 values were around −28‰. By contrast, African C4 tropical grass fire δ13CCH4 values were −16 to −12‰. Methane from urban landfills in Zambia and Zimbabwe, which have frequent waste fires, had δ13CCH4 around −37 to −36‰. These new isotopic values help improve isotopic constraints on global methane budget models because atmospheric δ13CCH4 values predicted by global atmospheric models are highly sensitive to the δ13CCH4 isotopic signatures applied to tropical wetland emissions. Field and aircraft campaigns also observed widespread regional smoke pollution over Africa, in both the wet and dry seasons, and large urban pollution plumes. The work highlights the need to understand tropical greenhouse gas emissions in order to meet the goals of the UNFCCC Paris Agreement, and to help reduce air pollution over wide regions of Africa
Parâmetros da degradação protéica ruminal de diferentes alimentos e rações estimados por técnica in vitro
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
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