Ny-Ålesund is an international research settlement where the thermodynamics and chemical composition of the air are monitored. The present work investigates the effects of micrometeorological conditions, mesoscale dynamics and local air pollution on the data collected at two different locations around the village. Daily filter measurements of sulphur dioxide and non-sea salt sulphate from the temporary Ny-Ålesund station and permanent Zeppelin mountain station have been analysed along with meteorological data. The influence of different factors representing micrometeorological phenomena and local pollution from ships has been statistically investigated. Seasonal variation of the correlation between the data from Ny-Ålesund and Zeppelin stations is revealed, and the seasonal dependence of the relative contribution of different factors has been analysed. The median concentrations of SO 4 2measured in Ny-Ålesund increased significantly on days with temperature inversions in winter. In spring, concentrations of SO 2 and SO 4 2were higher than normal at both stations on days with temperature inversions, but lower on days with strong humidity inversions. In summer, local ship traffic affects the SO 2 data set from Ny-Ålesund, while no statistically significant influence on the Zeppelin data set has been observed. The pollution from ships has an effect on SO 4 2values at both stations; however, the concentrations in Ny-Ålesund were higher when local pollution accumulated close to the ground in days with strong humidity inversions.

The Zeppelin observatory is a research station near the village Ny-Ålesund in Svalbard. The facility delivers data to international projects devoted to high data quality monitoring of the background air pollution in the Arctic. An approach for quantifying the influence of local and regional pollution on measurements that may be misinterpreted as long-range transported one, is presented here.The hourly gas and aerosol data measured in Ny-Ålesund and at the Zeppelin station, respectively, have been analysed along with the meteorological data from Ny-Ålesund, Zeppelin station and Longyearbyen (south-east of Ny-Ålesund).Seasonal fluctuation of the average measured values of SO 2 and NO x has been observed. Three main wind directions coincided with the peak concentration of SO 2 and NO x . The NW-N flow may bring local pollution from ship traffic and diesel power plant as well as biogenic SO 2 from the oxidation of DMS. The monthly average number of particles with diameter characteristic for ship plume (50-100 nm), was elevated for the hours when ships have been registered in the local call list. The number concentration of particles with diameter 200 nm, typical for Arctic haze events, and concentration of non-sea salt sulphate rise during springtime. The FLEXTRA-trajectory analysis indicated that most pollution brought by E-SE and SW flows may be of long-range and/or regional origin. Events with these flow directions need to be interpreted with caution.

Abstract. A total of 22 polycyclic aromatic hydrocarbons (PAHs), 29 oxy-PAHs, and 35 nitro-PAHs (polycyclic aromatic compounds, PACs) were measured in gaseous and particulate phases in the ambient air of Longyearbyen, the most populated settlement in Svalbard, the European Arctic. The sampling campaign started in the polar night in November 2017 and lasted for 8 months until June 2018, when a light cycle reached a sunlit period with no night. The transport regimes of the near-surface, potentially polluted air masses from midlatitudes to the Arctic and the polar boundary layer meteorology were studied. The data analysis showed the observed winter PAC levels were mainly influenced by the lower-latitude sources in northwestern Eurasia, while local emissions dominated in spring and summer. The highest PAC concentrations observed in spring, with PAH concentrations a factor of 30 higher compared to the measurements at the closest background station in Svalbard (Zeppelin, 115 km distance from Longyearbyen), were attributed to local snowmobile-driving emissions. The lowest PAC concentrations were expected in summer due to enhanced photochemical degradation under the 24 h midnight sun conditions and inhibited long-range atmospheric transport. In contrast, the measured summer concentrations were notably higher than those in winter due to the harbour (ship) emissions.

Abstract. Here we describe a versatile device to produce a flow of air-vapour mixture with controlled humidity and water isotope composition based on microdrop dispensing technology. By precisely controlling the contribution of water from two dispenser heads into a carrier gas stream, the device allows to set the air-vapour stream to any isotope ratio between two end member waters. In addition to presenting the design and several performance characteristics of the new system, we describe two application examples. First, we utilize the device to determine a common artifact of vapour isotope analyzers, known as the mixing ratio – isotope ratio dependency. Second, we utilize the device to provide a constant background stream of humid air for fluid inclusion water isotope analysis in stalagmites. The observed flexibility and precision of the device underpints its usefulness and potential for a wide range of applications in atmospheric water vapour isotope measurement applications. Future improvements could focus on reducing the number of manual interventions and improved control at high flow rates.