MetNH3 Whim Bog Intercomparison Off-line ammonia metrology intercomparison

There is no regular quality assurance programme for ammonia passive samplers despite widespread use of these samplers across Europe and the rest of the world. In order to improve standards and begin to embed quality assurance in the measurement of ambient ammonia using passive samplers, within the EMRP MetNH3 project a passive sampler intercomparison was planned to enable side-by side exposure of the samplers to varying levels of ammonia in the field. From this experiment and in parallel the NPL CATFAC experiment (also within MetNH3), sufficient information and protocols could be developed. The method and infrastructure developed will then be available for future studies

Drivers for spatial, temporal and long-term trends in atmospheric ammonia and ammonium in the UK

A unique long-term dataset from the UK National Ammonia Monitoring Network (NAMN) is used here to assess spatial, seasonal and long-term variability in atmospheric ammonia (NH3: 1998–2014) and particulate ammonium(NH4+: 1999–2014) across the UK. Extensive spatial heterogeneity in NH3 concentrations is observed, with lowest annual mean concentrations at remote sites (< 0.2 μg m-3 and highest in the areas with intensive agriculture (up to 22 μg m-3), while NH4+ concentrations show less spatial variability (e.g. range of 0.14 to 1.8 μg m-3 annual mean in 2005). Temporally, NH3 concentrations are influenced by environmental conditions and local emission sources. In particular, peak NH3 concentrations are observed in summer at background sites (defined by 5 km grid average NH3 emissions < 1 kg N ha-1 yr-1 and in areas dominated by sheep farming, driven by increased volatilization of NH3 in warmer summer temperatures. In areas where cattle, pig and poultry farming is dominant, the largest NH3 concentrations are in spring and autumn, matching periods of manure application to fields. By contrast, peak concentrations of NH4+ aerosol occur in spring, associated with long-range transboundary sources. An estimated decrease in NH3 emissions by 16%between 1998 and 2014 was reported by the UK National Atmospheric Emissions Inventory. Annually averaged NH3 data from NAMN sites operational over the same period (n=59)show an indicative downward trend, although the reduction in NH3 concentrations is smaller and non-significant: Mann–Kendall (MK), -6.3 %; linear regression(LR), -3.1 %. In areas dominated by pig and poultry farming, a significant reduction in NH3 concentrations between 1998 and 2014 (MK: -22 %; LR: -21 %, annually averaged NH3/ is consistent with, but not as large as the decrease in estimated NH3 emissions from this sector over the same period (-39 %). By contrast, in cattle-dominated areas there is a slight upward trend (non-significant) in NH3 concentrations (MK: +12 %; LR: +3.6 %, annually averaged NH3, despite the estimated decline in NH3 emissions from this sector since 1998 (-11 %). At background and sheep-dominated sites, NH3 concentrations increased over the monitoring period. These increases (non-significant) at background (MK: C17 %; LR: C13 %, annually averaged data) and sheep-dominated sites (MK: +15 %; LR: +19 %, annually averaged data) would be consistent with the concomitant reduction in SO2 emissions over the same period, leading to a longer atmospheric lifetime of NH3, thereby increasing NH3 concentrations in remote areas. The observations for NH3 concentrations not decreasing as fast as estimated emission trends are consistent with a larger downward trend in annual particulate NH4+ concentrations (1999–2014: MK: -47 %; LR: -49 %, p < 0.01, n=23), associated with a lower formation of particulate NH4+ in the atmosphere from gas phase NH3

Acid gases and aerosol measurements in the UK (1999–2015): regional distributions and trends

The UK Acid Gases and Aerosol Monitoring Network (AGANet) was established in 1999 (12 sites, increased to 30 sites from 2006), to provide long-term national monitoring of acid gases (HNO3, SO2, HCl) and aerosol components (NO3-, SO42-, Cl-, Na+, Ca2+, Mg2+). An extension of a low-cost denuder-filter pack system (DELTA) that is used to measure NH3 and NH4+ in the UK National Ammonia Monitoring Network (NAMN) provides additional monthly speciated measurements for the AGANet. A comparison of the monthly DELTA measurement with averaged daily results from an annular denuder system showed close agreement, while the sum of HNO3 and NO3- and the sum of NH3 and NH4+ from the DELTA are also consistent with previous filter pack determination of total inorganic nitrogen and total inorganic ammonium, respectively. With the exception of SO2 and SO42-, the AGANet provides for the first time the UK concentration fields and seasonal cycles for each of the other measured species. The largest concentrations of HNO3, SO2, and aerosol NO3- and SO42- are found in south and east England and smallest in western Scotland and Northern Ireland, whereas HCl are highest in the southeast, southwest and central England, that may be attributed to dual contribution from anthropogenic (coal combustion) and marine sources (reaction of sea salt with acid gases to form HCl). Na+ and Cl- are spatially correlated, with largest concentrations at coastal sites, reflecting a contribution from sea salt. Temporally, peak concentrations in HNO3 occurred in late winter and early spring attributed to photochemical processes. NO3- and SO42- have a spring maxima that coincides with the peak in concentrations of NH3 and NH4+, and are therefore likely attributable to formation of NH4NO3 and (NH4)2SO4 from reaction with higher concentrations of NH3 in spring. By contrast, peak concentrations of SO2, Na+ and Cl- during winter are consistent with combustion sources for SO2 and marine sources in winter for sea salt aerosol. Key pollutant events were captured by the AGANet. In 2003, a spring episode with elevated concentrations of HNO3 and NO3¬- was driven by meteorology and transboundary transport of NH4NO3 from Europe. A second, but smaller episode occurred in September 2014, with elevated concentrations of SO2, HNO3, SO42-, NO3- and NH4+ that was shown to be from the Icelandic Holuhraun volcanic eruptions. Since 1999, AGANet has shown substantial decrease in SO2 concentrations relative to HNO3 and NH3, consistent with estimated decline in UK emissions. At the same time, large reductions and changes in the aerosol components provides evidence of a shift in the particulate phase from (NH4)2SO4 to NH4NO3. The potential for NH4NO3 to release NH3 and HNO3 in warm weather, together with the surfeit of NH3 also means that a larger fraction of the reduced and oxidised N is remaining in the gas phase as NH3 and HNO3 as indicated by the increasing trend in ratios of NH3:NH4+ and HNO3:NO3- over the 16 year period. Due to different removal rates of the component species by wet and dry deposition, this change is expected to affect spatial patterns of pollutant deposition with consequences for sensitive habitats with exceedance of critical loads of acidity and eutrophication. The changes are also relevant for human health effects assessment, particularly in urban areas as NH4NO3 constitutes a significant fraction of fine particulate matter (< 2.5 µm) that are linked to increased mortality from respiratory and cardiopulmonary diseases

Atmospheric ammonia, acid gas and aerosol monitoring in Northern Ireland. Year 1: March 2019 - February 2020

ALPHA® and DELTA® network A new network of 25 ammonia (NH3) monitoring sites implementing the UKCEH ALPHA® method (ALPHA® network) and 4 reactive gases and aerosols monitoring sites implementing the UKCEH DELTA® method (DELTA® network) was established in spring 2019 across Northern Ireland. The ALPHA® sites were selected to provide representative coverage of i) the range of modelled concentrations from FRAME (using the most recent 5 km NH3 emissions data for 2016), (ii) each of seven major dominant emission source classifications: cattle (beef and dairy), pigs & poultry, sheep, mixed, non-agricultural, fertiliser and background (very low emission density, < 1 kg N ha-1 yr-1), and (iii) spatial coverage across Northern Ireland. The aims of the measurements are to (i) explore spatial and temporal patterns in NH3 concentrations, (ii) compare results with the FRAME atmospheric transport model and for verification of UK NAEI emissions inventory and FRAME model, (iii) monitor and assess relationship between NH3 and interacting gases (HNO3, SO2) and inorganic particulate phase composition. Measurement data over the same period from existing UK long-term national network sites (Coleraine, Hillsborough, Lough Navar), and from the Ballynahone Bog project in Northern Ireland are also included in the report, to complement the network data. All measurements are made through monthly time-integrated sampling, which is cost-efficient for providing annual means while permitting detection of seasonal trends in the data. The first measurements in the ALPHA® and DELTA® networks started in early March 2019. The first full year of ratified monthly ALPHA® and DELTA® data for the period March 2019 – February 2020 are presented in this report. Calibration of ALPHA® NH3 data An annual field calibrated ALPHA® uptake rate is derived for each calendar year from the regression of passive ALPHA® versus active DELTA® measurements at nine inter-comparison sites in the UK National Ammonia Monitoring Network. The calibration is usually carried out in April each year, based on a full year of data from the preceding year. The updated uptake rate is then applied retrospectively to ALPHA® data for the year of calibration. Calibrated uptake rates derived from the UK national network are applied to the Northern Ireland ALPHA® network data. These were 0.0031665 m3 h-1 and 0.0031277 m3 h-1, for 2019 and 2020, respectively. At AFBI25 Hillsborough, ALPHA® and DELTA® measurement are co-located with parallel measurements

Tides in colliding galaxies

Long tails and streams of stars are the most noticeable upshots of galaxy collisions. Their origin as gravitational, tidal, disturbances has however been recognized only less than fifty years ago and more than ten years after their first observations. This Review describes how the idea of galactic tides emerged, in particular thanks to the advances in numerical simulations, from the first ones that included tens of particles to the most sophisticated ones with tens of millions of them and state-of-the-art hydrodynamical prescriptions. Theoretical aspects pertaining to the formation of tidal tails are then presented. The third part of the review turns to observations and underlines the need for collecting deep multi-wavelength data to tackle the variety of physical processes exhibited by collisional debris. Tidal tails are not just stellar structures, but turn out to contain all the components usually found in galactic disks, in particular atomic / molecular gas and dust. They host star-forming complexes and are able to form star-clusters or even second-generation dwarf galaxies. The final part of the review discusses what tidal tails can tell us (or not) about the structure and content of present-day galaxies, including their dark components, and explains how tidal tails may be used to probe the past evolution of galaxies and their mass assembly history. On-going deep wide-field surveys disclose many new low-surface brightness structures in the nearby Universe, offering great opportunities for attempting galactic archeology with tidal tails.Comment: 46 pages, 13 figures, Review to be published in "Tidal effects in Astronomy and Astrophysics", Lecture Notes in Physics. Comments are most welcom

Fenn’s, Whixall, Bettisfield, Wem & Cadney Mosses. Atmospheric ammonia monitoring data report for period: Jul 2018 – Dec 2018

Three atmospheric ammonia (NH3) measurement sites were established on Fenn’s, Whixall, Bettisfield, Wem and Cadney Mosses SSSi in 2018 to monitor NH3 during implementation of Site Nitrogen Action Plan (SNAP), as part of the LIFE project. NH3 data from the three sites for the six monthly measurement periods between July and December 2018 have been analysed and are presented in this report. NH3 data from former NAMN Fenn’s Moss (S52B and S52C) and Wem Moss (S48) sites and from an active NAMN Fenn;s Moss (S52A) site are also included for comparison and to extend the time series. Monitored mean concentrations for the 6 months period from July to Dec 2018 were: MM1 = 2.64 µg NH3 m-3 (1.89 – 3.47 µg NH3 m-3, N = 6) MM2 = 6.15 µg NH3 m-3 (3.09 – 15.5 µg NH3 m-3, N = 6) MM3 = 3.28 µg NH3 m-3 (2.25 – 4.31 µg NH3 m-3, N = 6) By comparison, mean concentration for the UK NAMN site S52A (centre of Fenn’s Moss) over the same period was 3.53 µg NH3 m-3 (1.95 – 5.45 µg NH3 m-3, N = 6). The UNECE Critical Levels of NH3 concentrations of 1 µg NH3 m-3 annual mean for the protection of lichens-bryophytes, relevant for the habitat under study, was exceeded at all sites

Elemental concentrations (Ca, Cs, K, Mg, Sr) in a range of crops and associated soils from the UK and Spain

Data comprise elemental concentrations of Ca, Cs, K, Mg, Sr, NH4-N and NPOC (Non-Purgeable Organic Carbon) measured by ICPMS (Inductively Coupled Plasma Mass Spectrometry), ICPOES (Inductively Coupled Plasma Optical Emission Spectroscopy) or high temperature combustion catalytic oxidation. Samples include a range of freeze-dried crops (grass, radish, potato, strawberry, lettuce, courgette, chard) relevant to the human food chain, soil, soil pore waters and irrigation water. All samples were obtained following two plant growth studies conducted at CEH Lancaster during spring/summer 2018 and 2019 and a study conducted at the University of Extremadura (Cáceres) in the summer of 2018. The study was conducted as part of the CONFIDENCE project which is part of the CONCERT EJP, which receives funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 662287

Ennerdale Water fortnightly monitoring report 2015

Report to United Utilities as part of the Compensatory Measure R1