167 research outputs found
Monitoring trace metals and organohalogens in shellfish (2014) and physicochemical parameters and trace metals in seawater (2015) under the Shellfish Waters Directive
Directive 2006/113/EC on the Quality Required of Shellfish Waters, also referred to as the Shellfish Waters Directive (SWD) requires the monitoring of, inter alia, certain physicochemical parameters including trace metal contaminants in order to assess and protect the quality of shellfish growing waters and the shellfish harvested from them. Sixty-four areas have been designated as Shellfish Waters (SWs) under SI 268 of 2006, SI 55 of 2009 and SI 464 of 2009. The SWD is concerned the quality of shellfish waters and applied waters designated by the Member States as needing protection or improvement in order to support shellfish (bivalve and gastropod molluscs) life and growth and thus to contribute to the high quality of shellfish products directly edible by man. The Marine Institute undertakes a monitoring programme to meet the requirements of the Water Framework Directive (WFD) 2000/60/EC Transitional and Coastal (TraC) Waters and physico-chemical elements of the SWD
Summary Report on 2015 Residue Monitoring of Irish Farmed Finfish and 2015 Border Inspection Post Fishery and Fishery Product Sample Testing
On behalf of the Department of Agriculture, Food and Marine (DAFM), the Marine Institute carries out monitoring of chemical residues in finfish for aquaculture sector. This monitoring is set out in the annual National Residue Control Plan, which is approved by the European Commission, and is an important component of the DAFM food safety controls and is implemented under a service contract with the Food Safety Authority of Ireland. Since 1999, the Marine Institute has implemented the National Residues Monitoring Programme for aquaculture. This is carried out on behalf of the Sea Fisheries Protection Authority, which is the responsible organisation for residue controls on farmed finfish. The outcome for residues levels in farmed finfish during 2015 remains one of consistently low occurrence. In 2015, in excess of 676 tests and a total of 1,845 measurements were carried out on 128 samples (i.e. 124 target samples & 4 suspect samples) of farmed finfish for a range of chemical substances, including banned and unauthorised substances, various authorised veterinary treatments and environmental contaminants
Stable isotopic signatures of methane from waste sources through atmospheric measurements
This study aimed to characterize the carbon isotopic signatures (δ13C-CH4) of several methane waste sources, predominantly in the UK, and during field campaigns in the Netherlands and Turkey. CH4 plumes emitted from waste sources were detected during mobile surveys using a cavity ring-down spectroscopy (CRDS) analyser. Air samples were collected in the plumes for subsequent isotope analysis by gas chromatography isotope ratio mass spectrometry (GC-IRMS) to characterize δ13C-CH4. The isotopic signatures were determined through a Keeling plot approach and the bivariate correlated errors and intrinsic scatter (BCES) fitting method. The δ13C-CH4 and δ2H-CH4 signatures were identified from biogas plants (−54.6 ± 5.6‰, n = 34; −314.4 ± 23‰ n = 3), landfills (−56.8 ± 2.3‰, n = 43; −268.2 ± 2.1‰, n = 2), sewage treatment plants (−51.6 ± 2.2‰, n = 15; −303.9 ± 22‰, n = 6), composting facilities (−54.7 ± 3.9‰, n = 6), a landfill leachate treatment plant (−57.1 ± 1.8‰, n = 2), one water treatment plant (−53.7 ± 0.1‰) and a waste recycling facility (−53.2 ± 0.2‰). The overall signature of 71 waste sources ranged from −64.4 to −44.3‰, with an average of −55.1 ± 4.1‰ (n = 102) for δ13C, −341 to −267‰, with an average of −300.3 ± 25‰ (n = 11) for δ2H, which can be distinguished from other source types in the UK such as gas leaks and ruminants. The study also demonstrates that δ2H-CH4 signatures, in addition to δ13C-CH4, can aid in better waste source apportionment and increase the granularity of isotope data required to improve regional modelling
Comparing optimized CO emission estimates using MOPITT or NOAA surface network observations
[1] This paper compares two global inversions to estimate carbon monoxide (CO) emissions for 2004. Either surface flask observations from the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL) Global Monitoring Division (GMD) or CO total columns from the Measurement of Pollution in the Troposphere (MOPITT) instrument are assimilated in a 4D-Var framework. Inferred emission estimates from the two inversions are consistent over the Northern Hemisphere (NH). For example, both inversions increase anthropogenic CO emissions over Europe (from 46 to 94 Tg CO/yr) and Asia (from 222 to 420 Tg CO/yr). In the Southern Hemisphere (SH), three important findings are reported. First, due to their different vertical sensitivity, the stations-only inversion increases SH biomass burning emissions by 108 Tg CO/yr more than the MOPITT-only inversion. Conversely, the MOPITT-only inversion results in SH natural emissions (mainly CO from oxidation of NMVOCs) that are 185 Tg CO/yr higher compared to the stations-only inversion. Second, MOPITT-only derived biomass burning emissions are reduced with respect to the prior which is in contrast to previous (inverse) modeling studies. Finally, MOPITT derived total emissions are significantly higher for South America and Africa compared to the stations-only inversion. This is likely due to a positive bias in the MOPITT V4 product. This bias is also apparent from validation with surface stations and ground-truth FTIR columns. Our results show that a combined inversion is promising in the NH. However, implementation of a satellite bias correction scheme is essential to combine both observational data sets in the SH
Clusters in the inner spiral arms of M51: the cluster IMF and the formation history
We study the cluster population in a region of 3.2x3.2 kpc^2 in the inner
spiral arms of the intergacting galaxy M51, at a distance of about 1 to 3 kpc
from the nucleus, based on HST--WFPC2 images taken through five broadband and
two narrowband filters. We found 877 cluster candidates and we derived their
ages, initial masses and extinctions by comparing their energy distribution
with the Starburst99 cluster models. We describe the 3 and 2-dimensional
least-square energy fitting method that was used (3DEF, 2DEF). The lack of
[OIII] emission in even the youngest clusters with strong H-alpha emission,
indicates the absence of the most massive stars and suggests a mass upper limit
of about 25 to 30 solar masses. The mass versus age distribution of the
clusters shows a drastic decrease in the number of clusters with age, which
indicates that cluster disruption is occurring on a timescale of about 10 Myr
for low mass clusters. The cluster initial mass function for clusters younger
than 10 Myr has an exponent of alpha = 2.0 (+- 0.05) We derived the cluster
formation history from clusters with an initial mass larger than 10^4 solar
masses. There is no evidence for a peak in the cluster formation rate within a
factor two at about 200 to 400 Myr ago, i.e. at the time of the interaction
with the companion galaxy NGC 5194.Comment: 15 pages, 15 figures. Accepted for publication by Astronomy and
Astrophysic
A multi-year methane inversion using SCIAMACHY, accounting for systematic errors using TCCON measurements
This study investigates the use of total column CH<sub>4</sub> (<i>X</i>CH<sub>4</sub>) retrievals
from the SCIAMACHY satellite instrument for quantifying large-scale emissions
of methane. A unique data set from SCIAMACHY is available spanning almost a
decade of measurements, covering a period when the global CH<sub>4</sub> growth rate
showed a marked transition from stable to increasing mixing ratios. The TM5
4DVAR inverse modelling system has been used to infer CH<sub>4</sub> emissions from a
combination of satellite and surface measurements for the period 2003–2010.
In contrast to earlier inverse modelling studies, the SCIAMACHY retrievals
have been corrected for systematic errors using the TCCON network of ground-based Fourier transform spectrometers. The aim is to further investigate the
role of bias correction of satellite data in inversions. Methods for bias
correction are discussed, and the sensitivity of the optimized emissions to
alternative bias correction functions is quantified. It is found that the use
of SCIAMACHY retrievals in TM5 4DVAR increases the estimated inter-annual
variability of large-scale fluxes by 22% compared with the use of only
surface observations. The difference in global methane emissions between 2-year periods before and after July 2006 is estimated at 27–35 Tg yr<sup>−1</sup>. The use
of SCIAMACHY retrievals causes a shift in the emissions from the
extra-tropics to the tropics of 50 ± 25 Tg yr<sup>−1</sup>. The large uncertainty in
this value arises from the uncertainty in the bias correction functions.
Using measurements from the HIPPO and BARCA aircraft campaigns, we show that
systematic errors in the SCIAMACHY measurements are a main factor limiting
the performance of the inversions. To further constrain tropical emissions of
methane using current and future satellite missions, extended validation
capabilities in the tropics are of critical importance
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Sixteen years of MOPITT satellite data strongly constrain Amazon CO fire emissions
Despite consensus on the overall downward trend in Amazon forest loss in the previous decade, estimates of yearly carbon emissions from deforestation still vary widely. Estimated carbon emissions are currently often based on data from local logging activity reports, changes in remotely sensed biomass as well as remote detection of fire hotspots, and burned area. Here, we use sixteen years of satellite-derived carbon monoxide (CO) columns to constrain fire CO emissions from the Amazon basin between 2003 and 2018. Through data assimilation, we produce 3-daily maps of fire CO emissions over the Amazon that we verified to be consistent with a long-term monitoring program of aircraft CO profiles over five sites in the Amazon. Our new product independently confirms a long-term decrease of 54 % in deforestation-related CO emissions over the study period. Interannual variability is large, with known anomalously dry years showing a more than fourfold increase in basin-wide fire emissions. At the level of individual Brazilian states, we find that both soil moisture anomalies and human ignitions determine fire activity, suggesting that future carbon release from fires depends on drought intensity as much as on continued forest protection. Our study shows that the atmospheric composition perspective on deforestation is a valuable additional monitoring instrument that complements existing bottom-up and remote sensing methods for land-use change. Extension of such a perspective to an operational framework is timely considering the observed increased fire intensity in the Amazon basin in 2019–2021.</p
Mercury assessment in the marine environment: assessment criteria comparison (EAC/EQS) for mercury
Mercury is known for its worldwide environmental impact. It is addressed by several existing international agreements addressing atmospheric emissions (CLRTAP), the marine environment (OSPAR, HELCOM, Barcelona, Bucharest), waste (Basel), and export of chemicals (Rotterdam). It can be brought into the biosphere by humans by two different mechanisms: 1) intentional extraction and use, and 2) as a natural constituent in other materials. Mercury is extremely toxic to both man and biota and can be transformed within the aquatic environment into more toxic organic compounds (e.g. methyl mercury). A main pathway of mercury to the sea is atmospheric and it can be carried long distances from its source. The primary risk to the general population is exposure to methylmercury via ingestion of aquatic foods. OSPAR measures and subsequent EU measures regulate the main industrial sources for mercury releases to the environment. A suite of OSPAR measures control mercury emissions, discharges and sources. OSPAR has promoted actions in other international forums, especially the EU, e.g. call for actions to prevent pollution from the disposal of large amounts of pure and waste mercury arising from the closure or conversion of mercury cell chlor-alkali plants and for control measures on the use and marketing of mercury in various products
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