Jana Moldanova

Following the large reductions in sulfur emissions from shipping, NOx emissions have become a key remaining air-quality challenge in European coastal regions. This study assesses how international NOx regulations for ships, possible shortcomings in real-world implementation, and the local use of shore power affect air quality from the European scale down to the harbour-city scale. Shipping emissions were calculated for 2019, 2030, and 2040 and used in nested air-quality model simulations for Europe and Gothenburg, Sweden.European shipping NOx emissions decrease from 3263 kt in 2019 to 2270 kt in 2030 and 1075 kt in 2040 under full implementation of current and expected regulations. Without these NOx controls, emissions in 2040 would be more than twice as high, while partial failure of the regulation would increase emissions by about 40% relative to full implementation. The largest reductions in NO2 concentrations occur along major shipping lanes and in coastal regions, while reductions in PM2.5 concentrations are more widespread due to changes in secondary particle formation. In Gothenburg, local shipping mainly affects NO2 concentrations close to the harbour and fairways, whereas regional shipping contributes substantially to both NO2 and PM2.5 exposure over wide areas. Shore power provides clear local benefits by reducing emissions from ships at berth, but cannot replace regional NOx regulation.The results show that effective regulation, compliance control and local port measures are all needed to reduce shipping-related air pollution. Future use of ammonia-based fuels may introduce additional uncertainty through ammonia emissions and secondary PM formation.

The transport of passengers and freight around the world has increased dramatically in recent decades

Exhaust gases and particles from ships are a significant and growing contributor to the total emissions from transport. Globally, the sector is a significant contributor to global emissions of NOx and SO2.1,2 Recently, the International Maritime Organisation (IMO) has reduced the sulphur content of marine fuels globally through Annex VI of MARPOL, and sulphur emissions are further restricted in specific Sulphur Emission Control Areas (SECA), such as the English Channel between France and the UK. Similarly, NOx emission limits have been set for ships built after 2016 in NOx Emission Control Areas (NECA).However, other pollutants such as Volatile Organic Compounds (VOCs) or Particulate Matter (PM), are not regulated in relation to ship emissions. Here, we present new emission factors (EFs) for regulated and non-regulated pollutants from ship emissions derived from a land-based measurement campaign in the port of Dunkirk, France in the framework of the PIRATE and SHIPAIR projects. A comprehensive suite of gas-phase and particulate-phase pollutants was investigated with a focus on VOCs, based on PTR-MS measurements, and PM1 composition, based on AMS measurements. About 150 plumes were detected from three similar ferries, and EFs were calculated for 84 pollutants.Despite being located in an Emission Control Area (ECA) for SOx and NOx, we show that SO2 remains a reliable tracer of ship emissions for land-based measurements in the port area. A sensitivity test of the EF with respect to background considerations was performed, showing significant discrepancies depending on the method of background calculation. This underlines the importance of explicit background considerations in EF calculations.The EF of the particulate phase is dominated by the organic fraction (OA), between 0.05 and 15.88 g/kg fuel, two to three orders of magnitude higher than nitrate and sulphate. Particle Number (PN) EFs vary between 1.08·1014 and 1.60·1017 part./kgfuel, with a unimodal mode centred at 90 nm. The VOC EFs are dominated by oxygenated species, such as acetaldehyde (30.7 - 404.8 mg/kg fuel). The second most emitted group of VOCs are C5 cyclic compounds, of which cyclopentane has the highest EF (12.8 - 439.6 mg/kg fuel). Aromatic VOCs, such as benzene, toluene and xylenes, are also detected, with EFs below 80 mg/kg fuel. We also present the emissions as a function of the navigation phases, suggesting that certain pollutants are emitted more during the arrival of the ferries than during their departure. In particular, the speciated VOC EFs are expected to improve current emission inventories.References :(1) Aakko-Saksa, P. T. et al. Reduction in greenhouse gas and other emissions from ship engines: Current trends and future options. Progress in Energy and Combustion Science 94, 101055 (2023). (2) Lehtoranta, K. et al. Particulate Mass and Nonvolatile Particle Number Emissions from Marine Engines Using Low-Sulfur Fuels, Natural Gas, or Scrubbers. Environmental Science and Technology 53, 3315–3322 (2019).

Particulate and gaseous emissions were studied from a large two-stroke slow-speed diesel engine equipped with an open-loop scrubber, installed on a 78,200 metric tonnes (deadweight) containership, under real operation. This paper presents the on-board emission measurements conducted upstream and downstream of the scrubber with heavy fuel oil (HFO) and ultra-low sulfur fuel oil (ULSFO). Particle emissions were examined under various dilution ratios and temperature conditions, and with two thermal treatment setups, involving a thermodenuder (TD) and a catalytic stripper (CS). Our results show a 75% SO₂ reduction downstream of the scrubber with the HFO to emission-compliant levels, while the use of the ULSFO further decreased SO₂ levels. The operation of the scrubber produced higher particle number levels compared to engine-out, attributed to the condensational growth of nanometer particle cores, salt and the formation of sulfuric acid particles in the smaller size range, induced by the scrubber. The use of a TD and a CS eliminates volatiles but can generate new particles when used in high-sulfur conditions. The results of this study contribute to the generally limited understanding of the particulate and gaseous emission performance of open-loop scrubbers in ships and could feed into emission and air quality models for estimating marine pollution impacts.

Shipping contributes significantly to air pollutant emissions and atmospheric particulate matter (PM) concentrations. At the same time worldwide maritime transport volumes are expected to continue to rise in the future. The Mediterranean Sea is a major short-sea shipping route within Europe, as well as the main shipping route between Europe and East Asia. As a result, it is a heavily trafficked shipping area, and air quality monitoring stations in numerous cities along the Mediterranean coast have detected high levels of air pollutants originating from shipping emissions. The current study is a part of the EU Horizon 2020 project SCIPPER (Shipping contribution to Inland Pollution - Push for the Enforcement of Regulations) which intends to investigate how existing restrictions on shipping-related emissions to the atmosphere ensure compliance with legislation. To demonstrate the impact of ships on relatively large scales, the potential shipping impacts on various air pollutants can be simulated with chemistry transport models. To determine formation, transport, chemical transformation and fate of PM_2.5 in the Mediterranean Sea in 2015, five different regional chemistry transport models (CAMx – Comprehensive Air Quality Model with Extensions, CHIMERE, CMAQ – Community Multiscale Air Quality model, EMEP – European Monitoring and Evaluation Programme model, LOTOS-EUROS) were applied. Furthermore, PM_2.5 precursors (NH₃, SO₂, HNO₃) and inorganic particle species (SO₄²⁻, NH₄⁺, NO₃⁻) were studied, as they are important for explaining differences among the models. STEAM version 3.3.0 was used to compute shipping emissions, and the CAMS-REG v2.2.1 dataset was used to calculate land-based emissions for an area encompassing the Mediterranean Sea at a resolution of 12 × 12 km² (or 0.1° × 0.1°). For additional input, like meteorological fields and boundary conditions, all models utilized their regular configuration. The zero-out approach was used to quantify the potential impact of ship emissions on PM_2.5 concentrations. The model results were compared to observed background data from monitoring sites. Four of the five models underestimated the actual measured PM_2.5 concentrations. These underestimations are linked to model-specific mechanisms or underpredictions of particle precursors. The potential impact of ships on the PM_2.5 concentration is between 15 % and 25 % at the main shipping routes. Regarding particle species, SO₄²⁻ is main contributor to the absolute ship-related PM_2.5 and also to total PM_2.5 concentrations. In the ship-related PM_2.5, a higher share of inorganic particle species can be found when compared to the total PM_2.5. The seasonal variabilities in particle species show that NO₃⁻ is higher in winter and spring, while the NH₄⁺ concentrations displayed no clear seasonal pattern in any models. In most cases with high concentrations of both NH₄⁺ and NO₃⁻, lower SO₄²⁻ concentrations are simulated. Differences among the simulated particle species distributions might be traced back to the aerosol size distribution and how models distribute among the coarse and fine mode (PM_2.5 and PM₁₀). The seasonality of wet deposition follows the seasonality of the precipitation, displaying that precipitation predominates the wet deposition.

Shipping contributes significantly to air pollutant emissions and atmospheric particulate matter (PM) concentrations. At the same time worldwide maritime transport volumes are expected to continue to rise in the future. The Mediterranean Sea is a major short-sea shipping route within Europe, as well as the main shipping route between Europe and East Asia. As a result, it is a heavily trafficked shipping area, and air quality monitoring stations in numerous cities along the Mediterranean coast have detected high levels of air pollutants originating from shipping emissions. The current study is a part of the EU Horizon 2020 project SCIPPER (Shipping contribution to Inland Pollution - Push for the Enforcement of Regulations) which intends to investigate how existing restrictions on shipping-related emissions to the atmosphere ensure compliance with legislation. To demonstrate the impact of ships on relatively large scales, the potential shipping impacts on various air pollutants can be simulated with chemistry transport models. To determine formation, transport, chemical transformation and fate of PM_2.5 in the Mediterranean Sea in 2015, five different regional chemistry transport models (CAMx – Comprehensive Air Quality Model with Extensions, CHIMERE, CMAQ – Community Multiscale Air Quality model, EMEP – European Monitoring and Evaluation Programme model, LOTOS-EUROS) were applied. Furthermore, PM_2.5 precursors (NH₃, SO₂, HNO₃) and inorganic particle species (SO₄²⁻, NH₄⁺, NO₃⁻) were studied, as they are important for explaining differences among the models. STEAM version 3.3.0 was used to compute shipping emissions, and the CAMS-REG v2.2.1 dataset was used to calculate land-based emissions for an area encompassing the Mediterranean Sea at a resolution of 12 × 12 km² (or 0.1° × 0.1°). For additional input, like meteorological fields and boundary conditions, all models utilized their regular configuration. The zero-out approach was used to quantify the potential impact of ship emissions on PM_2.5 concentrations. The model results were compared to observed background data from monitoring sites. Four of the five models underestimated the actual measured PM_2.5 concentrations. These underestimations are linked to model-specific mechanisms or underpredictions of particle precursors. The potential impact of ships on the PM_2.5 concentration is between 15 % and 25 % at the main shipping routes. Regarding particle species, SO₄²⁻ is main contributor to the absolute ship-related PM_2.5 and also to total PM_2.5 concentrations. In the ship-related PM_2.5, a higher share of inorganic particle species can be found when compared to the total PM_2.5. The seasonal variabilities in particle species show that NO₃⁻ is higher in winter and spring, while the NH₄⁺ concentrations displayed no clear seasonal pattern in any models. In most cases with high concentrations of both NH₄⁺ and NO₃⁻, lower SO₄²⁻ concentrations are simulated. Differences among the simulated particle species distributions might be traced back to the aerosol size distribution and how models distribute among the coarse and fine mode (PM_2.5 and PM₁₀). The seasonality of wet deposition follows the seasonality of the precipitation, displaying that precipitation predominates the wet deposition.