| 1. |
- Beecken, Jörg, 1982, et al.
(författare)
-
Airborne emission measurements of SO2, NOx and particles from individual ships using a sniffer technique
- 2014
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 7:7, s. 1957-1968
-
Tidskriftsartikel (refereegranskat)abstract
- A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircraft. The system has been adapted for fast response measurements at 1 Hz, and the use of several of the instruments is unique. The uncertainty of the given data is about 20% for SO2 and 24% for NOx emission factors. The mean values with one standard deviation for multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8+/-6.5 g kg(fuel)(-1), 66.6+/-23.4 g kg(fuel)(-1) and 1.8+/-1.3 1016 particles kg(fuel)(-1) for SO2, NOx and particle number, respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 45 and 54 nm dependent on the distance to the source, and the number size distribution is monomodal. Concerning the sulfur fuel content, around 85% of the monitored ships comply with the International Maritime Organization (IMO) limits. The reduction of the sulfur emission control area (SECA) limit from 1.5 to 1% in 2010 appears to have contributed to reduction of sulfur emissions that were measured in earlier studies from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring.
|
|
| 2. |
- Beecken, Jörg, 1982, et al.
(författare)
-
Emission factors of SO2, NOx and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling
- 2015
-
Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 15:9, s. 5229-5241
-
Tidskriftsartikel (refereegranskat)abstract
- Emission factors of SO2, NOx and size-distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an Mi-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the Neva River in the urban area of Saint Petersburg. Most ships were running at reduced speed (10 kn), i.e., not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal, with averages of 4.6 and 18.2 gSO(2) kg(fuel)(-1) for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content Sulfur Emission Control Areas (SECA) limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal, with an average of 58 gNO(x) kg(fuel)(-1). The corresponding emission related to the generated power yields an average of 12.1 gNO(x) kWh(-1). The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 mu m size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm and the other for above 2 mu m. The average particle emission factors were found to be in the range from 0.7 to 2.7 x 10(16) particles kg(fuel)(-1) and 0.2 to 3.4 gPM kg(fuel)(-1), respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in international traffic, but significant deviations are found for inland vessels. Regarding particulate mass, the values of the modeled data are about 2-3 times higher than the measured results, which probably reflects the assumptions made in the modeled fuel sulfur content. The sulfur contents in the fuel retrieved from the measurements were lower than the previously used assumptions by the City of Saint Petersburg when carrying out atmospheric modeling, and using these measurements it was possible to better assess the impact of shipping on air quality.
|
|
| 3. |
- Mellqvist, Johan, 1965, et al.
(författare)
-
Certification of an aircraft and airborne surveillance of fuel sulfur content in ships at the SECA border
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In 2015 new rules from the IMO and legislation from EU (Sulfur directive) and the US requires ships to run with maximum fuel sulfur content (FSC) of 0.1 % m/m in northern European and North American waters. In order to promote a level playing field within the shipping sector, there is a need for measurement systems that can make effective compliance control and this is the main objective of the CompMon project, funded through the European CEF program (Connecting Europe Facility). As part of this project, a sensor system has been certified for ship surveillance measurements in a Piper Navajo aircraft and it has been demonstrated for airborne measurements of FSC in individual ships on the English Channel. The measurement system consists of an optical module which measures total emissions of SO2 and NO2 in g/s and a sniffer system by which FSC is retrieved from extractive measurements of SO2 and CO2. It can be used from fixed sites, patrol vessels and from aircraft. The advantage with airborne surveillance is the capability to check ships that are operating in the main shipping lanes, up to 200 nautical miles from shore. The precision of the estimated FSC from the sniffer system is 0.05 % m/m and hence at the 95 % confidence limit, ships above a FSC of 0.2 % m/m can be checked. The sniffer system also has a negative bias in the FSC of approx- imately 0.04 % m/m which is accounted for in the FSC calculations. The optical system has larger measurement uncertainties than the sniffer but it is intended mostly for guid- ance of other controls. As part of the CompMon project, a measurements campaign with the Navajo Piper aircraft was carried out at the SECA (Sulfur Emission Control Area) border in the English Channel at longitude 5 W. Six flight missions with duration of 4 to 5 hours were carried out from September 2 to 10, 2016, flying from Brest airport. In this manner it was possible to cover the longitude range 2o - 6o W. During the campaign, 114 ships were measured with the sniffer system, corresponding to 71 ships inside the SECA and 42 ships outside. The level of compli- ance inside the SECA was here 87 % and this is considerably lower than measurements carried out elsewhere within CompMon in other parts of the SECA (95-99 %). Two thirds of the non-complying vessels were leav- ing the SECA. With the optical system 110 individual ships were measured, 42 outside and 68 inside the SE- CA. The measurements show a similar pattern as the sniffer data but with a few false values. Nevertheless it is shown that both low and high FSC ships will be classified correctly with about 80-90 % probability with the optical system and this system is hence very promising as a tool to guide further compliance controls.
|
|
| 4. |
- Mellqvist, Johan, 1965, et al.
(författare)
-
Fixed remote surveillance of fuel sulfur content in ships from fixed sites in the Göteborg ship channel and Öresund bridge
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In 2015 new rules from the IMO and legislation from EU (Sulfur directive) and the US requires ships to run with maximum fuel sulfur content (FSC) of 0.1 % m/m in northern European and North American waters. In order to promote a level playing field within the shipping sector, there is a need for measurement systems that can make effective compliance control and this is the main objective of the CompMon project, funded through the European CEF program (Connecting Europe Facility). As part of this project, an automatic sniffer sensor system has been applied in the Göteborg ship channel at the Älvsborg island during 3 years (2014- 2016) and at the Öresund Bridge during two months at the end of 2016. The typical distances from the ships here varied between 500 -1000 m. The sniffer system is based on several extractive instruments measuring concentrations of SO2 and CO2 and others species, such as NOx, in the ship emission plumes that drift over the measurement station. In addition to fixed stations, the system can also be used from mobile platforms such as harbor patrol vessels and aircraft. From the data above, together with information about the ships from AIS (Automatic Identification System) and wind data, the FSC is automatically calculated and the ship is identi- fied. This is done using software developed as part of this project (Single Emitter identification Tool). The measurement precision (1σ) of the sniffer system is approx. 0.04 % m/m for ships using a FSC of 0.1 % m/m. The sniffer system also has a negative bias in the measured FSC, varying between 0.04 % to 0.08 % m/m and this is accounted for when calculating the threshold for non-compliance. Based on the above, it is possible to identify ships with FSC above 0.18 % m/m with 95% confidence limit, if the bias is corrected for statistically. For the measurements at the Älvsborg island site in 2014 and 2015, the corresponding limit is higher, 0.29 % m/m, due to a measurement artifact that was eliminated in 2016. On board measurements in 2015 and 2016 by the Swedish port state control authority shows that most non-compliant ships had FSCs be- tween 0.1 % to 0.2 % m/m when controlled at berth and this is generally below the 95% confidence limit threshold of the sniffer. Therefore many non-compliant ships will not be detected when using the sniffer close to harbors and a more precise sensor is therefore preferred. The measurements at the Älvsborg island were carried out during a time period when the allowed FSC limit changed significantly. The data for 2014, corresponding to more than 4000 measurements of 500 individual ships, shows that 99 % of the ships were using compliant fuel below the FSC limit of 1 % m/m. In 2015 the FSC limit changed to 0.1 % m/m. The measurements in 2015 and 2016, corresponding to the same amount of ships as in 2014, showed that 91.5 % and 98 %, respectively, were using compliant fuel with respect to FSC. The lower compliance rate in 2015 compared to 2016 is potentially influenced by measurement artifacts that were later eliminated in 2016. At the Öresund Bridge. 58 ships were measured as part of the CompMon pro- ject. The measurements continued another month with support from the interreg project Envisum, with anoth- er 62 ships measured. The compliance level at the Öresund Bridge corresponds to 98 %. This is actually com- parable to the corresponding measurements elsewhere and at the Älvsborg island site during the same time period.
|
|
| 5. |
|
|
| 6. |
- Mellqvist, Johan, 1965, et al.
(författare)
-
Quantification of stack emissions from marine vessels
- 2016
-
Ingår i: Air and Waste Management Association - Air Quality Measurement Methods and Technology Conference 2016. - 9781510822535 ; , s. 416-421
-
Konferensbidrag (refereegranskat)abstract
- Ship emission data from fixed and mobile platforms were obtained during 5 weeks in October and November of 2015. The main objective was to study the "real life" ship emissions of gases and particles in different modes of ship operation in the vicinity of the harbor, from open sea to berth. These emissions can be used to calculate the impact of shipping activities on air quality in the LA basin. Since ships are supposed to run on low sulfur fuel it is interesting how the new low sulfur fuel impacts also emissions of particles, in addition to sulfur. During the project we found several ships running on high sulfur fuel. During the presentation we will describe the method and show example of data from the project.
|
|
| 7. |
- Mellqvist, Johan, 1965, et al.
(författare)
-
Remote Quantification of Stack Emissions from Marine Vessels
- 2016
-
Ingår i: A&WMA’s 109th Annual Conference & Exhibition, New Orleans, Louisiana, June 2016. - 1052-6102. ; 1, s. 579-583
-
Konferensbidrag (refereegranskat)abstract
- Stationary and mobile (on-vessel) measurements of ship specific emission factors and total emission were carried out in the port of Los Angeles and Long Beach. The measurement techniques developed to characterize individual ship emissions were presented. The data were obtained with a zenith DOAS technique for NO 2 and "in-situ" sniffer technique for SO 2 , NO x , CO 2 , and particulates. The measured particle properties corresponded to particulate number, particulate mass, and black and organic carbon. Total emissions of NO 2 from the harbors were also obtained through mobile optical zenith sky measurements. The potential VOC emissions were investigated when fueling the ships and other VOC sources in the harbor using techniques like the Solar Occultation Flux technique. This is an abstract of a paper presented at the A & WMA's 109th Annual Conference & Exhibition (New Orleans, LA 6/20-23/2016).
|
|
| 8. |
- Mellqvist, Johan, 1965, et al.
(författare)
-
Surveillance of Sulfur Emissions from Ships in Danish Waters
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In 2015 new rules from the IMO and legislation from EU (Sulfur directive) requires ships to run with maximum fuel sulfur content (FSC) of 0.1 % m/m in northern European waters. In order to promote a level playing field within the shipping sector, there is a need for measurement systems that can make effective compliance control. This report describes the results from ship emission measurements on the waters surrounding Denmark from June 2015 to July 2017 on behalf of the Danish Environmental Protection Agency. The overall aim was to carry out operational surveillance of ships with respect to the EU sulfur directive and particularly the sulfur limits for marine fuel in the European Sulfur Emission Control Area (0.10 %), which entered into force on January 1st 2015, as well as to guide further port state control of ships at the destination harbors of the ships, both in Denmark and other ports. During the project the FSC of individual ships was estimated by perform- ing spot checks of exhaust plumes of individual ships. This was conducted by automatic gas sniffer measurements at the Great Belt Bridge and airborne surveillance measurements using sniffer and optical sensors. The data from the fixed system were transmitted in real time to a web database and alarms were triggered for high FSC ships in the form of emails. The report describes the technical systems and their performance and the general compliance levels of the measured ships. The measurement systems have been developed by Chalmers University of Technology through Swedish national funding and the EU project CompMon. The airborne dataset corresponds to approx. 900 individual ships, measured by sniffer or/and optical sensor over 245 flight hours. The optical sensor has low precision and is therefore used as a first alert system to identify ships running on high sulfur fuel. The precision of the airborne FSC meas- urements by the sniffer system is better and it is estimated as ± 0.05 % m/m (1σ) with a systematic bias of - 0.045 % m/m. Therefore only ships running with FSC of 0.2 % m/m or higher can be de- tected as non-compliant ships with good confidence limit (95 %) by the airborne sniffer system. The airborne measurements during 2015 and 2016 on Danish waters show that 94 % of the ships complied with the EU Sulphur directive, at the 95 % confidence limit. The compliance rate was lower, 92 %, during the 2nd half of 2016. In the period June 2015 to May 2017, 8426 sniffer measurements of individual ships were carried out at the Great Belt Bridge. However, there were technical problems in the first part of the project and the sniffer therefore had reduced sensitivity the first year and only high sulfur ships (> 1 % FSC) could be detected as non-complying vessels with appropriate statistical confidence. The precision in the estimated FSC by the fixed sniffer system is estimated as ± 0.04 % m/m (1σ) with a systematic bias of - 0.055 % m/m. Therefore only ships running with FSC of 0.18 % or higher can be detected as non-compliant ships with good confidence limit (95 %) by the fixed sniffer system. The data for the period June 2016 to October 2016 show a compliance rate of 94.6 % which increased to 97.4 % in the period January 2017 to May 2017. The compliance level during different time periods and platforms varied between 92-97 %. Here 1 - 2 % of the ships were in gross non-compliance with the EU sulfur directive with FSC values above 0.5 % m/m. There were differences over time, with the highest values in the summer of 2016. The compliance level was close to the values (95 %) measured by port state control authorities in Sweden and Denmark 2015 and 2016. When comparing ships measured by port state and the ones in this project it can be deduced that the efficiency of finding non-compliant vessels could be increased by at least a factor of 4, if the port state controls were guided by measurements. Most of the non-compliant ships (90 %) were measured high only once. But there were cases with individual ships and ship operators that were more abundant in the non-compliance statistics. The non- compliant ships that were seldom in the area around Denmark had higher emissions of SO2 than the non-compliant ones that operated their more frequently. On several occasions during this study we encountered ships equipped with scrubbers that were non-compliant with respect to the EU sulfur directive.
|
|
| 9. |
- Alföldy, B., et al.
(författare)
-
Measurements of air pollution emission factors for marine transportation in SECA
- 2013
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 6:7, s. 1777-1791
-
Tidskriftsartikel (refereegranskat)abstract
- The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg(-1) fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg(-1) fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 x 10(15) (kg fuel)(-1), gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 x 10(18), provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that similar to 144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was similar to 42 nm.
|
|
| 10. |
- Angelbratt, Jon, 1981, et al.
(författare)
-
A new method to detect long term trends of methane (CH4) and nitrous oxide (N2O) total columns measured within the NDACC ground-based high resolution solar FTIR network
- 2011
-
Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:13, s. 6167-6183
-
Tidskriftsartikel (refereegranskat)abstract
- Total columns measured with the ground-based solar FTIR technique are highly variable in time due to atmospheric chemistry and dynamics in the atmosphere above the measurement station. In this paper, a multiple regression model with anomalies of air pressure, total columns of hydrogen fluoride (HF) and carbon monoxide (CO) and tropopause height are used to reduce the variability in the methane (CH(4)) and nitrous oxide (N(2)O) total columns to estimate reliable linear trends with as small uncertainties as possible. The method is developed at the Harestua station (60 degrees N, 11 degrees E, 600 ma.s.l.) and used on three other European FTIR stations, i.e. Jungfraujoch (47 degrees N, 8 degrees E, 3600 ma.s.l.), Zugspitze (47 degrees N, 11 degrees E, 3000 ma.s.l.), and Kiruna (68 degrees N, 20 degrees E, 400 ma.s.l.). Linear CH(4) trends between 0.13 +/- 0.01-0.25 +/- 0.02% yr(-1) were estimated for all stations in the 1996-2009 period. A piecewise model with three separate linear trends, connected at change points, was used to estimate the short term fluctuations in the CH(4) total columns. This model shows a growth in 1996-1999 followed by a period of steady state until 2007. From 2007 until 2009 the atmospheric CH(4) amount increases between 0.57 +/- 0.22-1.15 +/- 0.17% yr(-1). Linear N(2)O trends between 0.19 +/- 0.01-0.40 +/- 0.02% yr(-1) were estimated for all stations in the 1996-2007 period, here with the strongest trend at Harestua and Kiruna and the lowest at the Alp stations. From the N(2)O total columns crude tropospheric and stratospheric partial columns were derived, indicating that the observed difference in the N(2)O trends between the FTIR sites is of stratospheric origin. This agrees well with the N(2)O measurements by the SMR instrument onboard the Odin satellite showing the highest trends at Harestua, 0.98 +/- 0.28% yr(-1), and considerably smaller trends at lower latitudes, 0.27 +/- 0.25% yr(-1). The multiple regression model was compared with two other trend methods, the ordinary linear regression and a Bootstrap algorithm. The multiple regression model estimated CH(4) and N(2)O trends that differed up to 31% compared to the other two methods and had uncertainties that were up to 300% lower. Since the multiple regression method were carefully validated this stresses the importance to account for variability in the total columns when estimating trend from solar FTIR data.
|
|
| 11. |
- Angelbratt, Jon, 1981, et al.
(författare)
-
Carbon monoxide (CO) and ethane (C2H6) trends from ground-based solar FTIR measurements at six European stations, comparison and sensitivity analysis with the EMEP model
- 2011
-
Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:17, s. 9253-9269
-
Tidskriftsartikel (refereegranskat)abstract
- Trends in the CO and C(2)H(6) partial columns (similar to 0-15 km) have been estimated from four European ground-based solar FTIR (Fourier Transform InfraRed) stations for the 1996-2006 time period. The CO trends from the four stations Jungfraujoch, Zugspitze, Harestua and Kiruna have been estimated to -0.45 +/- 0.16%yr(-1), -1.00 +/- 0.24%yr(-1), -0.62 +/- 0.19%yr(-1) and -0.61 +/- 0.16%yr(-1), respectively. The corresponding trends for C(2)H(6) are -1.51 +/- 0.23%yr(-1), -2.11 +/- 0.30%yr(-1), -1.09 +/- 0.25%yr(-1) and -1.14 +/- 0.18%yr(-1). All trends are presented with their 2-sigma confidence intervals. To find possible reasons for the CO trends, the global-scale EMEP MSC-W chemical transport model has been used in a series of sensitivity scenarios. It is shown that the trends are consistent with the combination of a 20% decrease in the anthropogenic CO emissions seen in Europe and North America during the 1996-2006 period and a 20% increase in the anthropogenic CO emissions in East Asia, during the same time period. The possible impacts of CH(4) and biogenic volatile organic compounds (BVOCs) are also considered. The European and global-scale EMEP models have been evaluated against the measured CO and C(2)H(6) partial columns from Jungfraujoch, Zugspitze, Bremen, Harestua, Kiruna and Ny-Alesund. The European model reproduces, on average the measurements at the different sites fairly well and within 10-22% deviation for CO and 14-31% deviation for C(2)H(6). Their seasonal amplitude is captured within 6-35% and 9-124% for CO and C(2)H(6), respectively. However, 61-98% of the CO and C(2)H(6) partial columns in the European model are shown to arise from the boundary conditions, making the global-scale model a more suitable alternative when modeling these two species. In the evaluation of the global model the average partial columns for 2006 are shown to be within 1-9% and 37-50% of the measurements for CO and C(2)H(6), respectively. The global model sensitivity for assumptions made in this paper is also analyzed.
|
|
| 12. |
- Beecken, Jörg, 1982, et al.
(författare)
-
Performance assessment of state-of-the-art and novel methods for remote compliance monitoring of sulfur emissions from shipping
- 2023
-
Ingår i: Atmospheric Measurement Techniques. - 1867-1381 .- 1867-8548. ; 16:23, s. 5883-5895
-
Tidskriftsartikel (refereegranskat)abstract
- The fuel sulfur content (FSC) of ocean-going and inland vessels was measured simultaneously by eight different state-of-the-art and novel monitoring systems during a 6-week campaign at the Elbe River, at a distance of about 10 km to the port of Hamburg, Germany. Both stationary and airborne systems on unoccupied aerial vehicles (UAVs) were operated by four participating partners in a side-by-side measurement setup to measure the emission factors of the same emission sources. A novel laser spectrometer, with significantly better-precision specifications as compared with the other instruments, was used for the first time for emission monitoring regarding the International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI regulations. The comparison took place in the North Sea sulfur emission control area (SECA), where the allowed FSC is limited to 0.10 %Sm/m. The unit %Sm/m relates to the percentage of mass sulfur per mass combusted fuel. In total, 966 plumes that originated from 436 different vessels were analysed in this study. At the same time, fuel samples obtained from 34 different vessels and bunker delivery notes (BDNs) from five frequently monitored vessels were used as a reference to assess the uncertainties of the different systems. Seven of the eight measurement systems tended to underestimate the FSC found from fuel samples and BDNs. A possible relation between underestimation and high relative humidities (above 80 %) was observed. The lowest systematic deviations were observed for the airborne systems and the novel laser spectrometer. The two UAV-borne systems showed total uncertainties of 0.07 %Sm/m and 0.09 %Sm/m (confidence level: 95 %). The novel laser spectrometer showed the lowest total uncertainty of 0.05 %Sm/m compared with other stationary sniffer systems, whose total uncertainties range from 0.08 %Sm/m to 0.09 %Sm/m. It was concluded that non-compliant vessels, with an actual FSC of the combusted fuel above 0.15 %Sm/m to 0.19 %Sm/m, can be detected by the compared systems with 95 % confidence.
|
|
| 13. |
- Berg, Niklas, 1980, et al.
(författare)
-
Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms
- 2012
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 5:5, s. 1085-1098
-
Tidskriftsartikel (refereegranskat)abstract
- A unique methodology to measure gas fluxes of SO2 and NO2 from ships using optical remote sensing is described and demonstrated in a feasibility study. The measurement system is based on Differential Optical Absorption Spectroscopy using reflected skylight from the water surface as light source. A grating spectrometer records spectra around 311 nm and 440 nm, respectively, with the telescope pointed downward at a 30A degrees angle from the horizon. The mass column values of SO2 and NO2 are retrieved from each spectrum and integrated across the plume. A simple geometric approximation is used to calculate the optical path. To obtain the total emission in kg h(-1) the resulting total mass across the plume is multiplied with the apparent wind, i.e. a dilution factor corresponding to the vector between the wind and the ship speed. The system was tested in two feasibility studies in the Baltic Sea and Kattegat, from a CASA-212 airplane in 2008 and in the North Sea outside Rotterdam from a Dauphin helicopter in an EU campaign in 2009. In the Baltic Sea the average SO2 emission out of 22 ships was (54 +/- 13) kg h(-1), and the average NO2 emission was (33 +/- 8) kg h(-1), out of 13 ships. In the North Sea the average SO2 emission out of 21 ships was (42 +/- 11) kg h(-1), NO2 was not measured here. The detection limit of the system made it possible to detect SO2 in the ship plumes in 60% of the measurements when the described method was used. A comparison exercise was carried out by conducting airborne optical measurements on a passenger ferry in parallel with onboard measurements. The comparison shows agreement of (-30 +/- 14)% and (-41 +/- 11)%, respectively, for two days, with equal measurement precision of about 20%. This gives an idea of the measurement uncertainty caused by errors in the simple geometric approximation for the optical light path neglecting scattering of the light in ocean waves and direct and multiple scattering in the exhaust plume under various conditions. A tentative error budget indicates uncertainties within 30-45% but for a reliable error analysis the optical light path needs to be modelled. A ship emission model, FMI-STEAM, has been compared to the optical measurements showing an 18% overestimation and a correlation coefficient (R-2) of 0.6. It is shown that a combination of the optical method with modelled power consumption can estimate the sulphur fuel content within 40%, which would be sufficient to detect the difference between ships running at 1% and at 0.1%, limits applicable within the IMO regulated areas.
|
|
| 14. |
- Blumenstock, T., et al.
(författare)
-
Characterization and potential for reducing optical resonances in Fourier transform infrared spectrometers of the Network for the Detection of Atmospheric Composition Change (NDACC)
- 2021
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 14:2, s. 1239-1252
-
Tidskriftsartikel (refereegranskat)abstract
- Although optical components in Fourier transform infrared (FTIR) spectrometers are preferably wedged, in practice, infrared spectra typically suffer from the effects of optical resonances ("channeling") affecting the retrieval of weakly absorbing gases. This study investigates the level of channeling of each FTIR spectrometer within the Network for the Detection of Atmospheric Composition Change (NDACC). Dedicated spectra were recorded by more than 20 NDACC FTIR spectrometers using a laboratory mid-infrared source and two detectors. In the indium antimonide (InSb) detector domain (1900-5000 cm-1), we found that the amplitude of the most pronounced channeling frequency amounts to 0.1 ‰ to 2.0 ‰ of the spectral background level, with a mean of (0:68±0:48) ‰ and a median of 0.60 ‰. In the mercury cadmium telluride (HgCdTe) detector domain (700-1300 cm-1), we find even stronger effects, with the largest amplitude ranging from 0.3 ‰ to 21 ‰ with a mean of (2:45±4:50) ‰ and a median of 1.2 ‰. For both detectors, the leading channeling frequencies are 0.9 and 0.11 or 0.23 cm-1 in most spectrometers. The observed spectral frequencies of 0.11 and 0.23 cm-1 correspond to the optical thickness of the beam splitter substrate. The 0.9 cm-1 channeling is caused by the air gap in between the beam splitter and compensator plate. Since the air gap is a significant source of channeling and the corresponding amplitude differs strongly between spectrometers, we propose new beam splitters with the wedge of the air gap increased to at least 0.8. We tested the insertion of spacers in a beam splitter's air gap to demonstrate that increasing the wedge of the air gap decreases the 0.9 cm-1 channeling amplitude significantly. A wedge of the air gap of 0.8 reduces the channeling amplitude by about 50 %, while a wedge of about 2 removes the 0.9 cm-1 channeling completely. This study shows the potential for reducing channeling in the FTIR spectrometers operated by the NDACC, thereby increasing the quality of recorded spectra across the network.
|
|
| 15. |
- Boikos, Christos, et al.
(författare)
-
Validating CFD modelling of ship plume dispersion in an urban environment with pollutant concentration measurements
- 2024
-
Ingår i: Atmospheric Environment. - 1873-2844 .- 1352-2310. ; 319
-
Tidskriftsartikel (refereegranskat)abstract
- Air pollution in urban areas constitutes a global environmental problem, with shipping being one major contributor to hazardous pollutants in harbour areas. This work concerns the application of a method using CFD modelling to study how ships affect the air quality of port areas at a microscale level. A steady RANS-CFD approach was applied to simulate the dispersion of shipping-emitted pollutants, and a spatial sensitivity analysis of the CFD modelling results was conducted. The port of Marseille was used as a case study, and the CFD predictions were compared with on-site observations from two monitoring stations for CO2, CO, NOx, SO2 and PM concentrations. Representative modelled and measured concentrations were considered at the location of the monitoring stations to facilitate one-by-one comparisons for all pollutants in three different test cases of departing vessels. The modelling predictions presented an 8.2% (95% CI: -9.3%, 25.7%) average deviation from the measurements. Validation metrics were included to conduct a statistical comparison between predicted and measured concentrations, with almost all metric values indicating acceptable agreement between the CFD model and measurements. From a technical perspective, this study demonstrates the reliability of the applied CFD modelling method in estimating shipping plume dispersion, while from a societal perspective, this model can serve as an advisory tool for port authorities and policy makers to reduce the impact of shipping emissions on urban air quality.
|
|
| 16. |
|
|
| 17. |
- de Foy, B., et al.
(författare)
-
Modelling constraints on the emission inventory and on vertical dispersion for CO and SO2 in the Mexico City Metropolitan Area using Solar FTIR and zenith sky UV spectroscopy
- 2007
-
Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 7, s. 781-801
-
Tidskriftsartikel (refereegranskat)abstract
- Emissions of air pollutants in and around urban areas lead to negative health impacts on the population. To estimate these impacts, it is important to know the sources and transport mechanisms of the pollutants accurately. Mexico City has a large urban fleet in a topographically constrained basin leading to high levels of carbon monoxide ( CO). Large point sources of sulfur dioxide (SO2) surrounding the basin lead to episodes with high concentrations. An Eulerian grid model (CAMx) and a particle trajectory model ( FLEXPART) are used to evaluate the estimates of CO and SO2 in the current emission inventory using mesoscale meteorological simulations from MM5. Vertical column measurements of CO are used to constrain the total amount of emitted CO in the model and to identify the most appropriate vertical dispersion scheme. Zenith sky UV spectroscopy is used to estimate the emissions of SO2 from a large power plant and the Popocatepetl volcano. Results suggest that the models are able to identify correctly large point sources and that both the power plant and the volcano impact the MCMA. Modelled concentrations of CO based on the current emission inventory match observations suggesting that the current total emissions estimate is correct. Possible adjustments to the spatial and temporal distribution can be inferred from model results. Accurate source and dispersion modelling provides feedback for development of the emission inventory, verification of transport processes in air quality models and guidance for policy decisions.
|
|
| 18. |
- De Gouw, J. A., et al.
(författare)
-
Airborne Measurements of Ethene from Industrial Sources Using Laser Photo-Acoustic Spectroscopy
- 2009
-
Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 43:7, s. 2437-2442
-
Tidskriftsartikel (refereegranskat)abstract
- A laser photoacoustic spectroscopy (LPAS) instrument was developed and used for aircraft measurements of ethene from industrial sources near Houston, Texas. The instrument provided 20 s measurements with a detection limit of less than 0.7 ppbv. Data from this instrument and from the GC-FID analysis of air samples collected in flight agreed within 15% on average. Ethene fluxes from the Mt. Belvieu chemical complex to the northeast of Houston were quantified during 10 different flights. The average flux was 520 +/- 140 kg h(-1) in agreement with independent results from solar occultation flux (SOF) measurements, and roughly an order of magnitude higher than regulatory emission inventories indicate. This study shows that ethene emissions are routinely at levels that qualify as emission upsets, which need to be reported to regional air quality managers.
|
|
| 19. |
- de Laat, A. T. J., et al.
(författare)
-
Validation of five years (2003-2007) of SCIAMACHY CO total column measurements using ground-based spectrometer observations
- 2010
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 3:5, s. 1457-1471
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a validation study of SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) carbon monoxide (CO) total column measurements from the Iterative Maximum Likelihood Method (IMLM) algorithm using ground-based spectrometer observations from twenty surface stations for the five year time period of 2003-2007. Overall we find a good agreement between SCIAMACHY and ground-based observations for both mean values as well as seasonal variations. For high-latitude Northern Hemisphere stations absolute differences between SCIAMACHY and ground-based measurements are close to or fall within the SCIAMACHY CO 2 sigma precision of 0.2 x 10(18) molecules/cm(2) (similar to 10%) indicating that SCIAMACHY can observe CO accurately at high Northern Hemisphere latitudes. For Northern Hemisphere mid-latitude stations the validation is complicated due to the vicinity of emission sources for almost all stations, leading to higher ground-based measurements compared to SCIAMACHY CO within its typical sampling area of 8 degrees x 8 degrees. Comparisons with Northern Hemisphere mountain stations are hampered by elevation effects. After accounting for these effects, the validation provides satisfactory results. At Southern Hemisphere mid-to high latitudes SCIAMACHY is systematically lower than the ground-based measurements for 2003 and 2004, but for 2005 and later years the differences between SCIAMACHY and ground-based measurements fall within the SCIAMACHY precision. The 2003-2004 bias is consistent with previously reported results although its origin remains under investigation. No other systematic spatial or temporal biases could be identified based on the validation presented in this paper. Validation results are robust with regard to the choices of the instrument-noise error filter, sampling area, and time averaging required for the validation of SCIAMACHY CO total column measurements. Finally, our results show that the spatial coverage of the ground-based measurements available for the validation of the 2003-2007 SCIAMACHY CO columns is sub-optimal for validation purposes, and that the recent and ongoing expansion of the ground-based network by carefully selecting new locations may be very beneficial for SCIAMACHY CO and other satellite trace gas measurements validation efforts.
|
|
| 20. |
|
|
| 21. |
- Dos Reis Vechi, Natalia, 1992, et al.
(författare)
-
Quantification of methane emissions from cattle farms, using the tracer gas dispersion method
- 2022
-
Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809. ; 330
-
Tidskriftsartikel (refereegranskat)abstract
- In Denmark, agriculture is the largest source of anthropogenic methane emissions (81%), mainly from cattle (dairy and beef) farms. Whole-farm methane emissions were quantified at nine Danish cattle farms, using the tracer gas dispersion method. Five to six measurement campaigns were carried out at each farm, covering a full year. Of the nine cattle farms, seven were home to dairy cows and two to beef cattle. The farms represented typical breeds, housing and management systems used in Denmark. Whole-farm methane emission rates ranged from 0.7 to 28 kg h−1, with the highest measurements seen at locations with the highest number of animals. Emissions tended to be higher from August to October, due to elevated temperatures and high amounts of stored manure during this period of the year. The average emission factor (EF) for dairy cow farms was 26 ± 8.5 g Livestock Unit (LU)−1 h−1, whereas it was 16 ± 4.1 LU−1 h−1 for beef cattle farms, i.e. 38% lower for the latter. The use of deep litter house management explained some of the differences found in the EFs for dairy cows. Methane emission rates estimated using IPCC models and national guidelines tended, on average for all farms and measurements, to be underestimated by 35% in comparison with the measured methane emissions, for all models and farms. The results suggest that future improvements to inventory models should focus on enteric methane emissions from beef cattle and manure methane emissions for both dairy cows and beef cattle, especially from deep litter management.
|
|
| 22. |
|
|
| 23. |
- Ericsson, M., et al.
(författare)
-
Measurements of fugitive emission using the Solar Occultation Flux (SOF) method
- 2013
-
Ingår i: Air Quality Measurement Methods and Technology Conference 2013; Sacramento, CA; United States; 19 November 2013 through 21 November 2013. ; , s. 457-460
-
Konferensbidrag (refereegranskat)abstract
- The SOF method is an emerging remote sensing technique based on measuring infrared intensity of solar spectra from a mobile platform (car, boat). From the infrared solar spectra, utilizing known absorption features and with a good knowledge of wind profile, the total mass of ethylene, propylene, alkanes and several other species along the path of the solar light can be retrieved. The method is today used to screen and quantify VOC emissions from industrial conglomerates down to sub-areas in individual plants. The SOF method is usually combined with mobile DOAS by which it is possible to measure also SO 2, NO2 and formaldehyde. The SOF method has been applied in several larger campaigns in both Europe and the US and in more than 70 individual plant surveys over the last 10 years. In the various campaign studies it has been found that the measured emissions obtained with SOF are 5-10 times higher than the reported emission obtained by standard calculation methods. For instance in studies in Houston, TexAQS 2006 and campaigns 2009 and 2011, it was shown that the industrial releases of alkenes for the Houston Galveston area, on average, were 10 times higher than what was reported. For alkanes the discrepancy factor was about 8.
|
|
| 24. |
- Flood, Victoria A., et al.
(författare)
-
Evaluating modelled tropospheric columns of CH4, CO, and O3 in the Arctic using ground-based Fourier transform infrared (FTIR) measurements
- 2024
-
Ingår i: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 24:2, s. 1079-1118
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluates tropospheric columns of methane, carbon monoxide, and ozone in the Arctic simulated by 11 models. The Arctic is warming at nearly 4 times the global average rate, and with changing emissions in and near the region, it is important to understand Arctic atmospheric composition and how it is changing. Both measurements and modelling of air pollution in the Arctic are difficult, making model validation with local measurements valuable. Evaluations are performed using data from five high-latitude ground-based Fourier transform infrared (FTIR) spectrometers in the Network for the Detection of Atmospheric Composition Change (NDACC). The models were selected as part of the 2021 Arctic Monitoring and Assessment Programme (AMAP) report on short-lived climate forcers. This work augments the model-measurement comparisons presented in that report by including a new data source: column-integrated FTIR measurements, whose spatial and temporal footprint is more representative of the free troposphere than in situ and satellite measurements. Mixing ratios of trace gases are modelled at 3-hourly intervals by CESM, CMAM, DEHM, EMEP MSC-W, GEM-MACH, GEOS-Chem, MATCH, MATCH-SALSA, MRI-ESM2, UKESM1, and WRF-Chem for the years 2008, 2009, 2014, and 2015. The comparisons focus on the troposphere (0-7km partial columns) at Eureka, Canada; Thule, Greenland; Ny Ålesund, Norway; Kiruna, Sweden; and Harestua, Norway. Overall, the models are biased low in the tropospheric column, on average by -9.7% for CH4, -21% for CO, and -18% for O3. Results for CH4 are relatively consistent across the 4 years, whereas CO has a maximum negative bias in the spring and minimum in the summer and O3 has a maximum difference centered around the summer. The average differences for the models are within the FTIR uncertainties for approximately 15% of the model-location comparisons.
|
|
| 25. |
- Fredricsson, Malin, et al.
(författare)
-
Nationell luftövervakning Sakrapport med data från övervakning inom Programområde Luft t.o.m 2019
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Naturvårdsverket ansvarar för den nationella luftövervakningen i bakgrundsmiljö i Sverige. I rapporten redovisas resultat från verksamheten inom Programområde Luft avseende mätningar (genomförda av IVL, SU, SLU och SMHI) till och med 2019 och regionala modellberäkningar (utförda av SMHI) till och med 2018.För flertalet av de luftföroreningskomponenter som övervakas inom den nationella miljöövervakningen har det, sedan mätningarna startade för mellan 20 och 40 år sedan, generellt sett skett en avsevärd förbättring avseende såväl halter i luft som deposition i bakgrundsmiljö. Utvecklingen har dock varierat i något olika utsträckning beroende på komponenter och lokalisering i landet. Föroreningsbelastningen är oftast lägre ju längre norrut i landet man kommer.För de flesta ämnen som det finns miljökvalitetsnormer (MKN) respektive miljömål för ligger halterna i regional bakgrund avsevärt lägre än angivna gräns- och målvärden. Halterna av ozon överskrider dock i dagsläget (2019) MKN för hälsa.
|
|
