A5052964161- Atmospheric and Environmental Gas Dynamics
- Methane Hydrates and Related Phenomena
- Hydrocarbon exploration and reservoir analysis
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Coal Properties and Utilization
- Peatlands and Wetlands Ecology
- Geology and Paleoclimatology Research
- Climate change and permafrost
- Meteorological Phenomena and Simulations
- Air Quality Monitoring and Forecasting
- Arctic and Antarctic ice dynamics
- Fire effects on ecosystems
- Spectroscopy and Laser Applications
- Carbon Dioxide Capture Technologies
- Isotope Analysis in Ecology
- Air Quality and Health Impacts
- Groundwater flow and contamination studies
- Oil, Gas, and Environmental Issues
- Geological and Geochemical Analysis
- Climate variability and models
- Landfill Environmental Impact Studies
- Oil Spill Detection and Mitigation
- Cryospheric studies and observations
- Paleontology and Stratigraphy of Fossils
Royal Holloway University of London
2015-2025
University of Cambridge
1975-2023
Ida Darwin hospital
2023
Jet Propulsion Laboratory
2020
AGH University of Krakow
2016
University of London
2008
Universidad de Londres
2008
University of Saskatchewan
1987-1991
Institute of Mineralogy
1980
A factor of 2.5 increase in the global abundance atmospheric methane (CH 4 ) since 1750 contributes 0.5 Wm −2 to total direct radiative forcing by long-lived greenhouse gases (2.77 2009), while its role chemistry adds another approximately 0.2 indirect forcing. Since CH has a relatively short lifetime and it is very close steady state, reductions emissions would quickly benefit climate. Sensible emission mitigation strategies require quantitative understanding ’s budget sinks. Atmospheric...
Abstract Atmospheric methane grew very rapidly in 2014 (12.7 ± 0.5 ppb/year), 2015 (10.1 0.7 2016 (7.0 and 2017 (7.7 at rates not observed since the 1980s. The increase burden began 2007, with mean global mole fraction remote surface background air rising from about 1,775 ppb 2006 to 1,850 2017. Simultaneously 13 C/ 12 C isotopic ratio (expressed as δ CH4 ) has shifted, now trending negative for more than a decade. causes of methane's recent are therefore either change relative proportions...
Atmospheric concentrations of the greenhouse gas methane are rising, but reasons remain incompletely understood.
Abstract From 2007 to 2013, the globally averaged mole fraction of methane in atmosphere increased by 5.7 ± 1.2 ppb yr −1 . Simultaneously, δ 13 C CH4 (a measure C/ 12 isotope ratio methane) has shifted significantly more negative values since 2007. Growth was extreme 2014, at 12.5 0.4 ppb, with a further shift being observed most latitudes. The isotopic evidence presented here suggests that rise dominated significant increases biogenic emissions, particularly tropics, for example, from...
More than 250 plumes of gas bubbles have been discovered emanating from the seabed West Spitsbergen continental margin, in a depth range 150–400 m, at and above present upper limit hydrate stability zone (GHSZ). Some extend upward to within 50 m sea surface. The is predominantly methane. Warming northward‐flowing current by 1°C over last thirty years likely increased release methane reducing extent GHSZ, causing liberation decomposing hydrate. If this process becomes widespread along Arctic...
Abstract The atmospheric methane burden is increasing rapidly, contrary to pathways compatible with the goals of 2015 United Nations Framework Convention on Climate Change Paris Agreement. Urgent action required bring back a pathway more in line goals. Emission reduction from “tractable” (easier mitigate) anthropogenic sources such as fossil fuel industries and landfills being much facilitated by technical advances past decade, which have radically improved our ability locate, identify,...
Abstract The 2015 Paris Agreement of the United Nations Framework Convention on Climate Change aims to keep global average temperature increases well below 2 °C preindustrial levels in Year 2100. Vital its success is achieving a decrease abundance atmospheric methane (CH 4 ), second most important anthropogenic greenhouse gas. If this reduction be achieved, individual nations must make and meet goals their nationally determined contributions, with regular independently verifiable stock...
Abstract Atmospheric methane's rapid growth from late 2006 is unprecedented in the observational record. Assessment of atmospheric methane data attributes a large fraction this to increased natural emissions over tropics, which appear be responding changes anthropogenic climate forcing. Isotopically lighter measurements are consistent with recent being mainly driven by an increase microbial sources, particularly wetlands. The global budget currently disequilibrium and new inputs as yet...
Global measurements of atmospheric methane have revealed a sharp decrease in the growth rate Northern Hemisphere during 1992. The average trend for 1983–1991 was (11.6±0.2) ppbv yr −1 , but increase 1992 only (1.8±1.6) ppbv. In Southern Hemisphere, (1983–1991) (11.1±0.2) and (7.7±1.0) Various possibilities change sources or sinks are discussed, most likely explanation is an anthropogenic source such as fossil fuel exploitation, which can be rapidly easily affected by man's activities.
European CH 4 emissions are estimated for the period 2001–2006 using a four‐dimensional variational (4DVAR) inverse modeling system, based on atmospheric zoom model TM5. Continuous observations used from various monitoring stations, complemented by and global flask samples NOAA/ESRL network. The available mainly provide information northwest Europe (NWE), including UK, Ireland, BENELUX countries, France Germany. estimates total anthropogenic NWE 21% higher compared to EDGARv4.0 emission...
Can national emissions inventories be verified through direct atmospheric measurements?
By com parison o f the methane m ixing ratio and carbon isotope (<513C ch4 ) in Arctic air w ith regional background, incremental input C H 4 an parcel source < 513C signature can be determined.Using this technique bulk soiuce arriving at Spitsbergen late summer 2008 2009 was found to -6 8 %o, indicative dominance a bio genic soiuce.This is close emissions from boreal wetlands.In spring, when wet land as frozen, th e sig n atu re ore enriched 13C -5 3 ± 6%o mass back trajectories indicating...
Abstract. High-precision analyses of the isotopic composition methane in ambient air can potentially be used to discriminate between different source categories. Due complexity isotope ratio measurements, such have generally been performed laboratory on samples collected field. This poses a limitation temporal resolution at which monitored with reasonable logistical effort. Here we present performance dual mass spectrometric system (IRMS) and quantum cascade laser absorption spectroscopy...
Abstract We present methane (CH 4 ) emissions for East Asia from a Bayesian inversion of CH mole fraction and stable isotope (δ 13 C‐CH measurements. Emissions were estimated at monthly resolution 2000 to 2011. A posteriori, the total emission increased 43 ± 59 Tg yr −1 between 2011, owing largely increase in China, 39 54 , while other Asian countries remained relatively stable. For South Korea, Japan, smaller than prior estimates (i.e., Emission Database Global Atmospheric Research 4.2...
Abstract Atmospheric measurements show an increase in CH 4 from the 1980s to 1998 followed by a period of near‐zero growth until 2007. However, 2007, has increased again. Understanding variability is critical for climate prediction and change mitigation. We examine role sources dominant sink, oxidation hydroxyl radical (OH), atmospheric over past three decades using observations , C 2 H 6 δ 13 CH4 inversion. From 2006 2014, microbial fossil fuel emissions 36 ± 12 15 8 Tg y −1 respectively....
Abstract We find that summer methane (CH 4 ) release from seabed sediments west of Svalbard substantially increases CH concentrations in the ocean but has limited influence on atmospheric levels. Our conclusion stems complementary measurements at seafloor, ocean, and atmosphere land‐based, ship aircraft platforms during a campaign 2014. detected high dissolved above seafloor with sharp decrease pycnocline. Model approaches taking potential emissions both bubble‐released larger region into...
Abstract Isotopic data provide powerful constraints on regional and global methane emissions their source profiles. However, inverse modeling of spatially resolved flux is currently constrained by a lack information the variability isotopic signatures. In this study, signatures in Fennoscandian Arctic have been determined chambers over wetland, air 0.3 to 3 m above wetland surface aircraft sampling from 100 wetlands up stratosphere. Overall, atmosphere has coherent δ 13 C signature −71 ± 1‰,...
The rising number of operational biogas plants in the UK brings a new emissions category to consider for methane monitoring, quantification and reduction. Minimising losses from atmosphere is critical not only because their contribution global warming but also with respect sustainability renewable energy production. Mobile greenhouse gas surveys were conducted detect plumes southern England that varied size, waste feed input materials utilization. Gaussian plume modelling was used estimate...
Abstract. Subsea permafrost and hydrates in the East Siberian Arctic Shelf (ESAS) constitute a substantial carbon pool, potentially large source of methane to atmosphere. Previous studies based on interpolated oceanographic campaigns estimated atmospheric emissions from this area at 8–17 TgCH4 yr−1. Here, we propose insights observations evaluate these estimates. The comparison high-resolution simulations mole fractions continuous during whole year 2012 confirms high variability...
Atmospheric methane (CH4) continues to increase, but there are multiple anthropogenic source categories that can be targeted for cost-effective emissions reduction. Cities emit CH4 the atmosphere from a mixture of sources, which include, not limited to, fugitive natural gas distribution systems, wastewater treatment facilities, waste-and rainwater networks, and landfills. Therefore, target mitigation measures, it is important locate quantify local urban prioritize opportunities in large...
Abstract Methane (CH 4 ) is a potent greenhouse gas with warming potential 84 times that of carbon dioxide (CO 2 over 20‐year period. Atmospheric CH concentrations have been rising since the nineteenth century but cause large increases post‐2007 disputed. Tropical wetlands are thought to account for ∼20% global emissions, African tropical understudied and their contribution uncertain. In this work, we use first airborne measurements sampled three wetland areas in Zambia derive emission...
Abstract. The Zeppelin Observatory (78.90∘ N, 11.88∘ E) is located on Mountain at 472 m a.s.l. Spitsbergen, the largest island of Svalbard archipelago. Established in 1989, observatory part Ny-Ålesund Research Station and an important atmospheric measurement site, one only a few high Arctic, several European global monitoring programmes research infrastructures, notably Monitoring Evaluation Programme (EMEP); Arctic Assessment (AMAP); Global Atmosphere Watch (GAW); Aerosol, Clouds Trace...
Abstract Small‐scale developments have been made to an off‐the‐shelf continuous‐flow gas chromatography/isotope‐ratio mass spectrometry (CF‐GC/IRMS) system allow high‐precision isotopic analysis of methane (CH 4 ) and carbon dioxide (CO 2 at ambient concentrations. The repeatability (1 σ obtainable with this is 0.05‰ for δ 13 C CH , 0.03‰ CO 18 O ten consecutive analyses a standard tank. An automated inlet system, which allows diurnal studies isotopes, also described. improved precision was...