Noise monitor 2016 : Validation of motorway and railway noise

Geluidniveaus gemeten op 38 punten langs rijkswegen lagen in 2015 gemiddeld 2 decibel hoger dan de berekende waarden. Op 39 meetlocaties langs het spoor kwamen de gemeten en berekende geluidniveaus in 2015 gemiddeld met elkaar overeen. Dit beeld stemt overeen met de voorgaande jaren 2013 en 2014. Op de afzonderlijke punten, zowel bij rijkswegen als het spoor, variëren verschillen ten opzichte van het gemiddelde. Bij de weg liggen de metingen tussen 2 decibel lager en 6 decibel hoger dan de berekende waarden, afhankelijk van het type en de lokale staat van het wegdek. De vergelijking van metingen met berekeningen is een verplichting uit de Wet milieubeheer. De weg- en spoorbeheerder, Rijkswaterstaat en ProRail, tonen via berekening aan of het geluid van de weg of het spoor onder de vastgestelde geluidproductieplafonds blijft. De berekende geluidniveaus worden jaarlijks door het RIVM gevalideerd met een steekproef van metingen. Dit rapport geeft ook de meetresultaten uit 2016 op 45 locaties langs de weg en 40 locaties langs het spoor. De meetresultaten uit 2016 zullen in een vervolgrapportage worden vergeleken met de rekenresultaten. De weg- en spoorbeheerder publiceren deze in de tweede helft van 2017.Noise levels measured at 38 sites along motorways in 2015, on average were 2 decibel higher than calculated values. At 39 measurement sites along the track, the measured and calculated noise levels in 2015, on average were in agreement. These results are consistent with previous years, 2013 and 2014. At the individual measurement sites, both for motorways and the track, differences may vary from the average. At motorways the measurements are within 2 dB lower and 6 dB higher compared with calculated values, depending on the type and the local condition of the road surface. The comparison of measured and calculated noise levels is a requirement of the environmental management Act. The road- and railway infrastructure manager, Rijkswaterstaat and ProRail, show by calculation whether the noise production from the road or the track complies with established noise limits. The calculated noise levels are validated by RIVM with a sample of measurements. This report also gives the latest results of measurements from 2016 at 45 sites along motorways and 40 sites along the track. The measured noise levels from 2016 will be compared with calculated levels, which will be published by the road- and railway infrastructure manager in the second half of 2017.Ministerie van I&

Two instruments based on differential optical absorption spectroscopy (DOAS) to measure accurate ammonia concentrations in the atmosphere

We present two Differential Optical Absorption Spectroscopy (DOAS) instruments built at RIVM: the RIVM DOAS and the miniDOAS. Both instruments provide virtually interference-free measurements of NH3 concentrations in the atmosphere, since they measure over an open path, without suffering from inlet problems or interference problems by ammonium aerosols dissociating on tubes or filters. They measure concentrations up to at least 200 mu g m(-3), have a fast response, low maintenance demands, and a high up-time. The RIVM DOAS has a high accuracy of typically 0.15 mu g m(-3) for ammonia for 5-min averages and over a total light path of 100 m. The miniDOAS has been developed for application in measurement networks such as the Dutch National Air Quality Monitoring Network (LML). Compared to the RIVM DOAS it has a similar accuracy, but is significantly reduced in size, costs, and handling complexity. The RIVM DOAS and miniDOAS results showed excellent agreement (R-2 = 0.996) during a field measurement campaign in Vredepeel, the Netherlands. This measurement site is located in an agricultural area and is characterized by highly variable, but on average high ammonia concentrations in the air. The RIVM-DOAS and miniDOAS results were compared to the results of the AMOR instrument, a continuous-flow wet denuder system, which is currently used in the LML. Averaged over longer time spans of typically a day, the (mini) DOAS and AMOR results agree reasonably well, although an off-set of the AMOR values compared to the (mini) DOAS results exists. On short time scales, the (mini) DOAS shows a faster response and does not show the memory effects due to inlet tubing and transport of absorption fluids encountered by the AMOR. Due to its high accuracy, high uptime, low maintenance and its open path, the (mini) DOAS shows a good potential for flux measurements by using two (or more) systems in a gradient set-up and applying the aerodynamic gradient technique

Replacing the AMOR with the miniDOAS in the ammonia monitoring network in the Netherlands

In this paper we present the continued development of the miniDOAS, an active differential optical absorption spectroscopy (DOAS) instrument used to measure ammonia concentrations in ambient air. The miniDOAS has been adapted for use in the Dutch National Air Quality Monitoring Network. The miniDOAS replaces the life-expired continuous-flow denuder ammonia monitor (AMOR). From September 2014 to December 2015, both instruments measured in parallel before the change from AMOR to miniDOAS was made. The instruments were deployed at six monitoring stations throughout the Netherlands. We report on the results of this intercomparison. Both instruments show a good uptime of ca. 90 %, adequate for an automatic monitoring network. Although both instruments produce 1 min values of ammonia concentrations, a direct comparison on short timescales such as minutes or hours does not give meaningful results because the AMOR response to changing ammonia concentrations is slow. Comparisons between daily and monthly values show good agreement. For monthly averages, we find a small average offset of 0.65 ± 0.28 µg m−3 and a slope of 1.034 ± 0.028, with the miniDOAS measuring slightly higher than the AMOR. The fast time resolution of the miniDOAS makes the instrument suitable not only for monitoring but also for process studies

Evaluation study of the suitability of instrumentation to measure ambient NH3 concentrations under field conditions

The uncertainties in emissions of ammonia (NH3) in Europe are large, partially due to the difficulty in monitoring of ambient concentrations due to its sticky nature. In the European Monitoring and Evaluation Program (EMEP) the current recommended guidelines to measure NH3 are by coated annular denuders with offline analysis. This method, however, is no longer used in most European countries and each one has taken a different strategy to monitor atmospheric ammonia due to the increase of commercial NH3 monitoring instrumentation available over the last 20 years. In June 2014, a 3 year project funded under the European Metrology Research Programme, “Metrology for Ammonia in Ambient Air” (MetNH3), started with the aim to develop metrological traceability for the measurement of NH3 in air from primary gas mixtures and instrumental standards to field application. This study presents the results from the field intercomparison (15 instruments) which was held in South East Scotland in August 2016 over an intensively managed grassland. The study compared active sampling methods to a meteorological traceable method which was developed during the project with the aim to produce a series of guidelines for ambient NH3 measurements. Preliminary results highlight both the importance of inlets and management of relative humidity in the measurement of ambient NH3 and of the requirement to carry out frequent intercomparison of NH3 instrumentation. Overall, it would be recommended from this study that a WMO-GAW world centre for NH3 would be established and support integration of standards into both routine and research measurements

Worldwide variations in artificial skyglow

Open access journalDespite constituting a widespread and significant environmental change, understanding of artificial nighttime skyglow is extremely limited. Until now, published monitoring studies have been local or regional in scope, and typically of short duration. In this first major international compilation of monitoring data we answer several key questions about skyglow properties. Skyglow is observed to vary over four orders of magnitude, a range hundreds of times larger than was the case before artificial light. Nearly all of the study sites were polluted by artificial light. A non-linear relationship is observed between the sky brightness on clear and overcast nights, with a change in behavior near the rural to urban landuse transition. Overcast skies ranged from a third darker to almost 18 times brighter than clear. Clear sky radiances estimated by the World Atlas of Artificial Night Sky Brightness were found to be overestimated by ~25%; our dataset will play an important role in the calibration and ground truthing of future skyglow models. Most of the brightly lit sites darkened as the night progressed, typically by ~5% per hour. The great variation in skyglow radiance observed from site-to-site and with changing meteorological conditions underlines the need for a long-term international monitoring program.MILIEU (FU Berlin)Federal Ministry of Education and Research, GermanyEU COST Action ES1204 (Loss of the Night Network)European Research Council (ERC) under the EU's Seventh Framework Program (FP7/2007-2013)panish Network for Light Pollution StudiesNational Aeronautics and Space Administration (Goddard Space Flight Center)Ohio State UniversityUniversity of IowaThe Adam Mickiewicz Universit

Field comparison of two novel open-path instruments that measure dry deposition and emission of ammonia using flux-gradient and eddy covariance methods

Dry deposition of ammonia (NH3) is the largest contributor to the nitrogen deposition from the atmosphere to soil and vegetation in the Netherlands, causing eutrophication and loss of biodiversity; however, data sets of NH3 fluxes are sparse and in general have monthly resolution at best. An important reason for this is that measurement of the NH3 flux under dry conditions is notoriously difficult. There is no technique that can be considered as the gold standard for these measurements, which complicates the testing of new techniques. Here, we present the results of an intercomparison of two novel measurement set-ups aimed at measuring dry deposition of NH3 at half hourly resolution. Over a 5-week period, we operated two novel optical open-path techniques side by side at the Ruisdael station in Cabauw, the Netherlands: the RIVM-miniDOAS 2.2D using the aerodynamic gradient technique, and the commercial Healthy Photon HT8700E using the eddy covariance technique. These instruments are widely different in their measurement principle and approach to derive deposition values from measured concentrations; however, both techniques showed very similar results (r=0.87) and small differences in cumulative fluxes (∼ 10 %) as long as the upwind terrain was homogeneous and free of nearby obstacles. The observed fluxes varied from ∼ −80 to ∼ +140 ng NH3 m−2 s−1. Both the absolute flux values and the temporal patterns were highly similar, which substantiates that both instruments were able to measure NH3 fluxes at high temporal resolution. However, for wind directions with obstacles nearby, the correlations between the two techniques were weaker. The uptime of the miniDOAS system reached 100 % once operational, but regular intercalibration of the system was applied in this campaign (35 % of the 7-week uptime). Conversely, the HT8700E did not measure during and shortly after rain, and the coating of its mirrors tended to degrade (21 % data loss during the 5-week uptime). In addition, the NH3 concentrations measured by the HT8700E proved sensitive to air temperature, causing substantial differences (range: −15 to +6 µg m−3) between the two systems. To conclude, the miniDOAS system appears ready for long-term hands-off monitoring. The current HT8700E system, on the other hand, had a limited stand-alone operational time under the prevailing weather conditions. However, under relatively dry and low-dust conditions, the system can provide sound results, opening good prospects for future versions, also for monitoring applications. The new high temporal resolution data from these instruments can facilitate the study of processes behind NH3 dry deposition, allowing an improved understanding of these processes and better parameterisation in chemical transport models.</p

Worldwide variations in artificial skyglow

Despite constituting a widespread and significant environmental change, understanding of artificial nighttime skyglow is extremely limited. Until now, published monitoring studies have been local or regional in scope, and typically of short duration. In this first major international compilation of monitoring data we answer several key questions about skyglow properties. Skyglow is observed to vary over four orders of magnitude, a range hundreds of times larger than was the case before artificial light. Nearly all of the study sites were polluted by artificial light. A non-linear relationship is observed between the sky brightness on clear and overcast nights, with a change in behavior near the rural to urban landuse transition. Overcast skies ranged from a third darker to almost 18 times brighter than clear. Clear sky radiances estimated by the World Atlas of Artificial Night Sky Brightness were found to be overestimated by ~25%; our dataset will play an important role in the calibration and ground truthing of future skyglow models. Most of the brightly lit sites darkened as the night progressed, typically by ~5% per hour. The great variation in skyglow radiance observed from site-to-site and with changing meteorological conditions underlines the need for a long-term international monitoring program

Geluidmonitor 2017 : Meting en validatie van geluidproductie door rijkswegen en spoorwegen

Het RIVM valideert jaarlijks geluid-berekeningsresultaten van de wegen spoorwegbeheerder, Rijkswaterstaat en ProRail. Dit gebeurt met een steekproef van metingen. Zowel de validatie als de berekeningen zijn een verplichting die voortkomt uit de Wet Milieubeheer. Validatie 2016 In 2016 lag de gemeten geluidproductie langs rijkswegen gemiddeld 2 decibel hoger dan de berekende waarden. Langs het spoor kwam in 2016 de gemeten en berekende geluidproductie gemiddeld met elkaar overeen. Dit beeld komt overeen met de resultaten van de jaren 2013, 2014 en 2015. Zowel bij rijks- als spoorwegen variëren de verschillen tussen rekenen en meten op afzonderlijke trajecten. Deze lopen uiteen van 2 decibel lager tot 6 decibel hoger bij rijkswegen, en 4 decibel lager tot 6 decibel hoger bij spoorwegen. Metingen 2017 Dit rapport geeft ook meetresultaten over 2017. Deze resultaten zullen in de geluidmonitor 2018 worden vergeleken met de rekenresultaten van Rijkswaterstaat en ProRail van 2018. De weg- en spoorbeheerder publiceren deze resultaten in de tweede helft van 2018. Daarna kunnen de resultaten worden vergeleken.Every year the motorway and railway authorities - Rijkswaterstaat and ProRail - are required to calculate the noise generated by road and railway traffic. RIVM validates these yearly noise calculations by taking their own measurement samples and comparing them with those calculated by the road and rail authorities. Both the above activities fall under the Environmental Management Act. Validation 2016 In 2016, on average, the noise produced along national motorways was 2 decibels higher than the calculated values; along railways noise levels agreed with the calculated values. This overall picture is consistent with the findings of previous noise monitoring exercises conducted in 2013, 2014 and 2015. On individual trajectories, the differences between calculation and measurement results varied. For national motorways, the distribution ranged from 2 decibels below to 6 decibels above the calculated levels; for railways, it ranged from 4 decibels below to 6 decibels above. Measurements 2017 This report also presents the measurement results for 2017 which, in due course, will be compared to the calculation results set down in the noise monitor 2018. The motorway and railway authorities publish these 2017 results during the second term of 2018. A comparison, therefore, can only be made after this date.Ministerie van Infrastructuur en Waterstaa

Comparative measurements with affordable DIY-noise meters

In Nederland is naar schatting 10 procent van de bevolking ernstig bezorgd over de effecten van geluid rond hun huis op hun gezondheid. Steeds meer mensen meten zelf de hoogte van het geluid bij hun woning met betaalbare, zelfgebouwde geluidmeters. Deze meters kunnen langere tijd geluid in de omgeving meten. In principe kan iedereen die een beetje handig is de geteste zelfbouw-geluidmeters bouwen: de data, de bouwinstructies en software zijn openbaar. Het RIVM ondersteunt deze ontwikkeling omdat de metingen inzicht kunnen geven in lokale geluidoverlast. Het heeft daarom in samenwerking met een aantal bouwers de kwaliteit van 7 typen geluidmeters getest. Hieruit blijkt dat de kwaliteit van de zelfgebouwde geluidmeters de afgelopen jaren veel beter is geworden en ze het erg goed kunnen doen. De meters kunnen ook tekortkomingen hebben. Sommige meten bijvoorbeeld niet goed in de regen en andere wijken af bij lage geluidniveaus. Voor het onderzoek zijn de zelfbouwmeters zes maanden lang gevolgd in een situatie die lijkt op de praktijk. De resultaten zijn vergeleken met de metingen van een klasse 1 referentie geluidmeter, die naast de zelfbouwmeters is gehangen. De resultaten staan op de website van het RIVM zodat iedereen een beeld kan krijgen van hoe deze geluidmeters werken en wat de voor- en nadelen zijn. Het RIVM hoopt met dit onderzoek te laten zien dat eenvoudige geluidmeters een meerwaarde hebben. Zowel bij burgers als lokale overheden die geïnteresseerd zijn in het meten van het geluid in de omgeving.An estimated 10 per cent of the Dutch population is seriously concerned about the health effects of noise around the home. Growing numbers of people are using affordable, home-made sound level meters to measure noise around the home themselves, thereby gaining insights into local noise pollution. These meters are capable of measuring ambient noise over a length of time. In principle, anyone with moderate DIY skills can build the home-made meters from the test described below, as the necessary data, assembly instructions and software are in the public domain. RIVM supports this development through its Samen Meten (Measure Together) platform. With that in mind, RIVM’s Samen Meten team has teamed up with a number of sound level meter builders to test the quality of seven meter types. The test results showed that the quality of the home-made sound level meters has improved greatly over the last few years, and some of them work very well indeed. However, the test also revealed a few shortcomings. For example, some meters work less well in the rain, and others produce unreliable readings when the ambient noise level is low. The test involved monitoring the readings of the home-made meters for six months in conditions that resembled practical reality. The readings were compared with the readings of a Class I reference sound level meter, which was positioned next to the home-made meters. The test results will be posted to the RIVM website, so that everyone can get an idea of how these sound level meters work and what their pros and cons are. This RIVM test shows that simple noise level meters are capable of great results. This means that they can be a valuable tool for both private citizens and local authorities to measure ambient noise

2018 Noise Monitor - Additional Research : Individual source emissions of road traffic and railway traffic

Rijkswaterstaat en ProRail berekenen, als beheerders van de rijkswegen en spoorwegen, elk jaar hoeveel geluid het verkeer op de weg en het spoor maakt. Het RIVM toetst de resultaten met metingen in de Geluidmonitor. Belangrijk aandachtspunt hierbij is hoe aannames in de rekenmethode over de gemiddelde hoeveelheid geluid van voertuigen en treinen zich verhouden tot de praktijk. De afgelopen jaren bedroegen de verschillen tussen meten en rekenen gemiddeld 2 decibel bij het wegverkeer en 0 decibel bij het spoorverkeer. Om de oorzaken van de verschillen te vinden, heeft het RIVM de belangrijkste factoren onder de loep genomen die invloed hebben op geluid. Hierbij is gekeken naar de effecten van banden en naar de kwaliteit van het wegdek. Daarnaast is onderzocht hoeveel geluid afzonderlijke voertuig- en treintypen produceren. Voertuigtypen In de rekenmethode wordt een correctie gemaakt voor stille banden. Sinds 2016 mogen geen banden meer worden verkocht die niet voldoen aan de Europese bandenrichtlijn. Dit geldt zowel voor personenauto's als voor vrachtauto's. Het rekenmodel loopt vooruit op de situatie van 2022, waarin naar verwachting alle (vracht)auto's door deze maatregel 1 tot 2 decibel stiller zijn. De metingen laten zien dat vrachtauto's de afgelopen drie jaar 1,5 decibel minder geluid zijn gaan maken. Voor personenauto's is het geluid echter hetzelfde gebleven. Invloed wegdek Een andere correctie in de rekenmethode is het type wegdek. Deze correctie gaat uit van een gemiddelde levensduur van het wegdek, ongeacht de conditie van het wegdek. Verschillen tussen de gemeten en berekende hoeveelheid geluid in de Geluidmonitor blijken echter voor een groot deel te verklaren door de staat van het wegdek. Het RIVM gaat daarom met Rijkswaterstaat het verband tussen de geluidproductie en de conditie van het wegdek nog verder onderzoeken. Treintypen Voor het treinverkeer is het type trein van invloed op de geluidproductie. In het rekenmodel zijn de verschillende treintypen, zoals de sprinter, opgenomen in afzonderlijke categorieën. De moderne sprinter blijkt echter, volgens de metingen, 3 tot 4 decibel minder geluid te maken dan de waarden die in de rekenmethode aan deze categorie wordt gegeven.Each year, Rijkswaterstaat (Directorate-General for Public Works and Water Management) and ProRail, in their role as road and railway managing authorities, calculate how much noise is produced by road traffic and railway traffic. RIVM checks the results via measurements in the Noise Monitor. An important element of the study was to evaluate to what degree assumptions made in the model calculations regarding the average quantity of noise produced by vehicles and trains actually reflected reality. In previous years, the difference between the value calculated by the model and the measured value was 2 decibels for road traffic and 0 decibels for railway traffic. In order to determine the causes of the differences, RIVM analysed the most important factors that have an effect on the noise level. In doing so, the effects of tyres and the quality of the road surface were analysed. In addition, the study analysed how much noise specific types of vehicles and trains produced. Vehicle types In the model calculations, a correction is made for quiet tyres. Since 2016, all tyres sold must meet the European tyre guideline. This applies to passenger cars as well as lorries. The calculation model anticipates the situation that will exist in 2022, when all cars/lorries will be 1 to 2 decibels quieter as a result of the above standard. The measurements show that the noise level produced by lorries has decreased by 1.5 decibels over the last three years. However, the noise produced by passenger cars has remained the same. Influence of road surface Another correction made in the model calculations concerns the type of road surface. This correction assumes an average lifespan for the road surface, regardless of the condition of the road surface. However, as it turns out, differences between the measured and calculated quantity of noise in the Noise Monitor can, for the most part, be explained by the condition of the road surface. RIVM, in collaboration with Rijkswaterstaat, will therefore further investigate the relationship between the production of noise and the condition of the road surface. Train types For train traffic, the type of train influences the noise production. In the calculation model, the different types of trains, such as the sprinter, are assigned to separate categories. However, according to the measurements, the modern sprinter train produces 3 to 4 decibels less noise than the values assigned to this category by the model.Ministerie van I&