Search

Ongoing climate change has a significant impact on marine and terrestrial polar ecosystems. The increased melting, and retreat of glaciers, as well as the permafrost thawing, intensify the transport of dissolved organic matter from land to Arctic fjords. It has been estimated that the permafrost surface layer contains as much as 1035 ± 150 Pg of organic carbon (Hugelius et al., 2014), so even a small release can significantly change the carbon loads reaching the fjords. Although there are quantitative estimations of the dissolved organic carbon (DOC) delivered from land, the fate of the soil-derived DOC in fjords remains highly unknown. It is still unclear to what extent this DOC pool is bioavailable and how fast can it be remineralized. Therefore, the following research objectives have been formulated: (1) to quantify the shares of labile, semi-labile, and refractory fractions in the soil-derived DOC, and (2) to estimate remineralization rate constants and half-life times for different bioavailable fractions of DOC. This has been done through the 180-days-lasting incubation experiments of the DOC released from soils (soil leachates) mixed with the seawater from adjacent fjord. At the beginning and after 1, 2, 3, 5, 9, 19, 29, 65, 90, and 180 days of incubation, the individual samples were collected to measure DOC concentrations. For the study site, the catchments of two rivers in Kongsfjorden (West Spitsbergen, Svalbard) - Bayelva River and Londonelva River were selected. Bayelva River is 4 km long, with a glacierised catchment area of 32 km2, which is almost entirely underlain by permafrost with a seasonal active layer (Killingtveit, 2004). Londonelva River is located on Blomstradøya (small island in Kongsfjorden) and is characterized by a small (0.7 km2) de-glacierised catchment area. The results indicate that the soil leachates contain a lot of DOC (420 μmol L-1 in the Bayelva catchment and 2730 μmol L-1 in the Londonelva catchment), which is highly bioavailable - 61% and 66% of DOC was remineralized during the incubation experiment, respectively. This high bioavailability of terrestrial DOC indicates that its supply has the potential to play an essential role in sustaining the bacterial loop in the fjord and, through the CO2 release, to amplify ocean acidification in the coastal zone. The obtained results contribute to a better understanding of the processes shaping the carbon cycling in the Arctic fjords (and likely in other polar regions).

Measurement of pCO2 in highly dynamic coastal zones such as the southern Baltic Sea presents many challenges. In this study, we designed a system to measure pCO2 and then validated it in a series of laboratory and seagoing tests. The fast response time of the system was shown to provide a better resolution of CO2 system gradients. In the open waters of the Baltic Sea, the accuracy of the pCO2 measurements (±1.3 µatm) met the requirements of the ICOS (±2.0 µatm). In the coastal zone, there was less consistency between pCO2, DIC and pH measurements, suggesting the need to redefine the quality assurance and control requirements for the measurement of pCO2 in dynamic regions.

Investigation results of a coarse and accumulation mode of aerosol properties above the Baltic Sea are reported. A most important role in the direct aerosol effect on climate have aerosols from the group of coarse and accumulation mode particles. Overseas in the atmosphere, there is a lot of aerosols from the fine fraction but their impact is not so important as coarse and accumulation mode particles. Sea spray emission from the sea surface takes place over a wide range of aerosol particle size distribution, it is also large in size range which are studying in this work ( Lewis and Schwartz, 2004 ). The discussed range is most important in view of atmospheric optical properties, smaller particles do not have such an influence on scattering as particles from range 0.5–2 µm. The research was performed with a multiwavelength lidar. Due to the application of special software, the aerosol particle size distributions were retrieved from the lidar returns. That provided an opportunity to determine the profiles of the aerosol effective radius. We showed that the aerosol properties depend mainly on the direction of the air mass advection and the wind speed. The impact of the Baltic Sea on the aerosol size distribution is huge in the case of the advection from the open sea. Moreover, the aerosol effective radiuses in the whole boundary layer are much larger in the case of strong than for light wind. Our results suggest that the aerosol flux and the aerosol particle size distribution should be related to the wind speed in the emission function.

Denitrification and anammox are the main nitrogen (N) removal pathways in seawaters. Both processes are important in regions, such as the Baltic Sea, which receive high nutrient loads, that enhance primary production and eutrophication. The Baltic Sea is also characterized by a strong vertical salinity gradient and the presence of a permanent halocline hampering mixing in the water column and ventilation of the deep water layers. Rare events of deep water renewal, together with high oxygen consumption, lead to suboxic and anoxic conditions in the Baltic Sea, which are favorable for denitrification and anammox – processes for which the end product is a non-reactive N2. In seawater, the concentration of dissolved gases is controlled by biological and physical processes. The latter can be traced by measuring inert gases such as argon (Ar). Hence, the N2/Ar ratio can be used to separate physical and biological effects influencing N2 fields. This approach may suit especially to the stratified water bodies, where deep waters are separated from the surface water layer influenced by the gas exchange with the atmosphere.The study aimed at investigating the potential use of the supersaturation ratio – ΔN2 as a tracer of denitrification and anammox processes in the water column of the Baltic Proper. The ΔN2 ratio was derived as an anomaly from the N2/Ar ratio in seawater being at equilibrium with the atmosphere. The used technique was Membrane Inlet Mass Spectrometry, which allows performing high-precision measurements of dissolved N2 and Ar in water (masses 28 and 40 were detected, respectively). Seawater samples were collected between 2017 and 2021 from nineteen stations, including Gdańsk, Gotland, and Bornholm Deeps.The ΔN2 indicated N2 accumulation in the oxygen minimum zones below the halocline with the highest values found​​ in the bottom layers. This can be explained by both denitrification and possibly anammox in the water column and with N2 release from sediments. ΔN2 values ranged from 1.0 to 32.6 µmol L-1. In autumn 2021 a significant difference in ΔN2 (p = 0.0008) between the studied sites was observed. For example on station located in Gotland Deep ΔN2 values were in the range from 17.6 to 32.6 µmol L-1, while on station located in the Central Baltic Proper the maximum was 6.1 µmol L-1. The seasonal ΔN2 changes (autumn, spring, and winter) were investigated for two stations located in the Gdańsk Deep and indicated statistically significant variability (p=0.0077) with the highest ΔN2 observed in winter. Additionally, ΔN2 was negatively correlated with nitrate (R2=0.5469) and oxygen (R2=0.6382), positively with phosphate (R2=0.4382) and ammonium (R2=0.2898), while no clear dependency was observed for nitrite (R2=0.0388).The presented study was the first attempt performed on such a large scale in the Baltic Proper. It demonstrates a high potential in the use of supersaturation ratio for identification of the active sites for denitrification and anammox processes. The results were obtained within the framework of the statutory activities of the Institute of Oceanology Polish Academy of Sciences and the research project: 2019/34/E/ST10/00217 funded by the Polish National Science Centre.

Microplastics (MPs) pollution is one of the most important problems of the Earth. They have been found in all the natural environments, including oceans and the atmosphere. In this study, the concentrations of both atmospheric and marine MPs were measured over the Baltic along a research cruise that started in the Gdansk harbour, till the Gotland island, and the way back. A deposition box (based on a combination of active/passive sampling) was used to collect airborne MPs while, marine MPs concentrations were investigated during the cruise using a dedicated net. Ancillary data were obtained using a combination of particle counters (OPC, LAS and CPC), Aethalometer (AE33 Magee Scientific), spectrofluorometer (sea surface samples, Varian Cary Eclipse), and meteorological sensors. Results showed airborne microplastics average concentrations higher in the Gdansk harbour (161 ± 75 m-3) compared to the open Baltic Sea and to the Gotland island (24 ± 9 and 45 ± 20 m-3). These latter values are closer to the ones measured in the sea (79 ± 18 m-3). The MPs composition was investigated using μ-Raman (for the airborne ones) and FTIR (for marine ones); similar results (e.g. polyethylene, polyethylene terephthalates, polyurethane, polystyrene) were found in the two environmental compartments. The concentrations and similar composition in air and sea suggested a linkage between the two compartments. For this purpose, the atmospheric MPs' equivalent aerodynamic diameter was calculated (28 ± 3 μm) first showing the capability of atmospheric MPs to remain suspended in the air. At the same time, the computed turnover times (0.3-90 h; depending on MPs size) limited the transport distance range. The estimated MPs sea emission fluxes (4-18 ∗ 106 μm3 m-2 s-1 range) finally showed the contemporary presence of atmospheric transport together with a continuous emission from the sea surface enabling a grasshopper long-range transport of microplastics across the sea.

The Poland-AOD aerosol research network was established in 2011 to improve aerosol–climate interaction knowledge and provide a real-time and historical, comprehensive, and quantitative database for the aerosol optical properties distribution over Poland. The network consists of research institutions and private owners operating 10 measurement stations and an organization responsible for aerosol model transport simulations. Poland-AOD collaboration provides observations of spectral aerosol optical depth (AOD), Ångstrom Exponent (AE), incoming shortwave (SW) and longwave (LW) radiation fluxes, vertical profiles of aerosol optical properties and surface aerosol scattering and absorption coefficient, as well as microphysical particle properties. Based on the radiative transfer model (RTM), the aerosol radiative forcing (ARF) and the heating rate are simulated. In addition, results from GEM-AQ and WRF-Chem models (e.g., aerosol mass mixing ratio and optical properties for several particle chemical components), and HYSPLIT back-trajectories are used to interpret the results of observation and to describe the 3D aerosol optical properties distribution. Results of Poland-AOD research indicate progressive improvement of air quality and at mospheric turbidity during the last decade. The AOD was reduced by about 0.02/10 yr (at 550 nm), which corresponds to positive trends in ARF. The estimated clear-sky ARF trend is 0.34 W/m2/10 yr and 0.68 W/m2/10 yr, respectively, at TOA and at Earth’s surface. Therefore, reduction in aerosol load observed in Poland can significantly contribute to climate warming.

The air-sea gas flux is proportional to the difference of partial pressure between the sea-water and the overlying atmosphere multiplied by gas transfer velocity k, a measure of the effectiveness of the gas exchange. Because wind is the source of turbulence making the gas exchange more effective, k is usually parameterized by wind speed. Unfortunately, measured values of gas transfer velocity at a given wind speed have a large spread in values. Surfactants have been long suspected as the main reason of this variability but few measurements of gas exchange and surfactants have been performed at open sea simultaneously and therefore their results were inconclusive. Only recently, it has been shown that surfactants may decrease the CO2 air-sea exchange by up to 50%. However the labour intensive methods used for surfactant study make it impossible to collect enough data to map the surfactant coverage or even create a gas transfer velocity parameterization involving a measure of surfactant activity. This is why we propose to use optical fluorescence as a proxy of surfactant activity. Previous research done by our group showed that fluorescence parameters allow estimation the surfactant enrichment of the surface microlayer, as well as types and origin of fluorescent organic matter involved. We plan to measure, from a research ship, all the variables needed for calculation of gas transfer velocity k (namely CO2 partial pressure both in water and in air as well as vertical flux of this trace gas) and to use mathematical optimization methods to look for a parameterization involving wind speed and one of the fluorescence parameters which will minimize the residual k variability. Although our research will still involve water sampling and laboratory fluorescence measurements, the knowledge of which absorption and fluorescence emission bands are the best proxy for surfactant activity may allow to create remote sensing products (fluorescence lidars) allowing continuous measurements of surfactant activity at least from the ship board, if not from aircraft and satellites. The improved parameterization of the CO2 gas transfer velocity will allow better constraining of basin-wide and global air-sea fluxes, an important component of global carbon budget. If an improved gas transfer velocity parametrization based on surfactant fluorescence spectrum in concert with a turbulence proxy (wind) were to be found, a tantalizing possibility arises of a remote sensing estimation of k. Namely a UV lidar can both excite and measure the fluorescence band identified as proxy of the surfactant effect on the gas transfer velocity. Depending on the wavelength bands needed to be utilized, the effect could be measured from a moving ship (already an improvements on methods needing sampling), an aircraft or possibly even a satellite. We intend to pursue this idea in cruises to both the Baltic and the North Atlantic, possibly in cooperation with other air-sea interaction groups (this presentation is in part an invitation to cooperation).

Black carbon (BC) and Brown Carbon (BrC) absorbs sunlight and heat the atmosphere. The heating rate (HR) can be determined from the divergence of the net radiative flux with altitude (vertical profiles) or from the modelling activity; however, it determination is, up to now, too sparse, does not account for light-absorbing-aerosol (LAA) speciation and for the influence of different cloudy sky conditions on the BC induced heating rate (HR) in the atmospheric layer below clouds. This work applies a new method (Ferrero et al., 2018) to experimentally determine (at high time resolution) the HR induced by the LAA from mid-latidudes to the Arctic along two years (2018-2019, June-August) of oceanographic cruises moving from 54°N to 81°N and from 2°W to 25°E.The HR was experimentally determined at high time resolution and apportioned in the context of LAA species (BC, BrC), and sources (fossil fuel, FF; biomass burning, BB) as reported in Ferrero et al. (2018) equipping the Oceania vessel of the Polish Academy of Science with the following instrumentation:1) Aethalometer (AE-33, Magee Scientific, 7-λ), 2) Multiplexer-Radiometer-Irradiometer ROX (diffuse, direct and reflected radiance: 350-1000 nm, 1 nm resolution), 3) a SPN1 radiometer (global and diffuse radiation), 4) High volume sampler (TSP ECHO-PUF Tecora). Samples were analysed for ions (Dionex IC) and by EC/OC by using DRI Model 2015 Multi-Wavelength Thermal/Optical Carbon Analyzer. Radiometers were compensated for the ship pitch and roll by an automatic gimbal. AE33 absorption coefficient accuracy was determined through comparison with a MAAP (Thermo-Fischer).The HR showed a clear latitudinal behavior with higher values in the harbor of Gdansk (0.29±0.01 K/day) followed by the Baltic Sea (0.04±0.01 K/day), the Norvegian Sea (0.01±0.01 K/day) and finally with the lowest values in the pure Arctic Ocean (0.003±0.001 K/day).They followed the decrease of both BC concentrations and global radiation from 1189±21 ng/m3 and 230±6 W/m2 (Gdansk) to 27±1 ng/m3 and 111±3 W/m2 (Arctic Ocean). The latitunal gradient of the HR clearly demonstrate that the warming of the Arctic could be influenced by a heat transport. In this respect, the LAA added about 300 J/m3 at mid-latitudes and only 3 J/m3 close to the North Pole. Moreover, above the Arctic circle, 70% of the HR was due to the diffuse radiation induced by cloud presence, a condition that climate models in clear-sky assumption cannot capture. In addition, in the Arctic the BrC experienced an increase of 60% in determining the HR compared to mid-latitudes.Acknowledgements: GEMMA Center - Project MIUR – Dipartimenti di Eccellenza 2018–2022.Reference: Ferrero, L., et al (2018) Environ. Sci Tech., 52, 3546−3555

This study presents the vertical profiles of aerosol optical and microphysical properties obtained from cable car and ground-based measurements in the Silesian Beskids, Poland. The data were collected during a measurement campaign between 25 February and March 11, 2018. An AE-51 micro-aethalometer and PMS7003 and OPC-N2 optical particle counters were mounted on the cable car and used to measure the profiles of equivalent of black carbon (eBC) concentration and aerosol size distribution. In situ measurements of the optical properties of the aerosols were obtained using an AE-31 aethalometer and photoacoustic devices. A prototype lidar was used to determine the planetary boundary layer (PBL) height and the aerosol layers. In the middle phase of the study (1–6 March 2018), significant night-time temperature inversions were observed. During the inversion period, the parameters describing the amount of aerosols in the air increased significantly. The concentration of eBC exceeded the level of 15 μg/m3 several times, with an average level of 5.39 ± 4.42 μg/m3. Conversely, the results obtained in the first and third phases of the experiment were at the level of the aerosol background, being 1.45 ± 0.88 μg/m3 and 0.90 ± 0.95 μg/m3, respectively. Significant differences were also observed in the vertical profiles of PM10 mass and eBC concentration. In the middle phase of the study, the profiles showed a significant reduction in the concentration of pollutants with height, while in the first and third phases, there were slight variations with height.

Summary This paper presents the results of a comparison of basic meteorological parameters in two Arctic fjords situated on the west coast of Spitsbergen, the main island of the Svalbard archipelago. Air temperature, wind speed and direction, humidity and cloud cover from the period 2005 to 2016 are described and compared with previous (from 1975) analyses of meteorological conditions in the investigated region. Such a choice of dates coincides with the time the GAME project measurements were carried out. The main goal of this study was to compare meteorological conditions in two fjords: Hornsund and Kongsfjorden, during the time of rapid climate changes. The results are collated with research results available in literature from previous years. We discovered that in the investigated period the climate of the Hornsund region is more oceanic than in Kongsfjorden. The stable level of the difference in climate elements is manifested and is evident mainly through greater amplitudes in air temperatures in Kongsfjorden, and in stronger winds in Hornsund.

Summary This paper presents the results of Aerosol Optical Depth (AOD) studies which took place in Ny-Alesund in the spring of 2014 during the iAREA campaign. The measurements were taken using Microtops II hand-held sunphotometers along the Kongsfjorden, on a path leading from the research village to the fjord opening. Local breeze circulation was observed during the measurement campaign which resulted in an evident increase of AOD along the measurement profile towards the open sea. Using the observed AOD, changes over the open sea have been calculated and the location of the breeze front has been determined.

The fluorescence and absorption measurements of the samples collected from a surface microlayer (SML) and a subsurface layer (SS), at a depth of 1 m, were studied during three research cruises in the Baltic Sea along with hydrophysical studies and meteorological observations. Several absorption (E2 : E3, S, SR) and fluorescence (fluorescence intensities at Coble classified peaks: A, C, M, T the ratio M + T∕A + C, HIX (humification index)) indices of colored and fluorescent dissolved organic matter (CDOM and FDOM) helped to describe the changes in molecular size and weight as well as in composition of organic matter. The investigation allowed the assessment of a decrease in the contribution of two terrestrial components (A and C) with increasing salinity ( ∼ 1.64 and ∼ 1.89 % in the SML and ∼ 0.78 and ∼ 0.71 % in the SS, respectively) and an increase in components produced in situ (M and T) with salinity ( ∼ 0.52 and ∼ 2.83 % in the SML and ∼ 0.98 and ∼ 1.87 % in the SS, respectively). Hence, a component T reveals the biggest relative changes along the transect from the Vistula River outlet to Gdansk Deep, in both the SML and SS, although an increase was higher in the SML than in the SS ( ∼ 18.5 and ∼ 12.3 %, respectively). The ratio E2 : E3 points to greater changes in the molecular weight of CDOM affected by a higher rate of photobleaching in the SML. The HIX index reflects a more advanced stage of humification and condensation processes in the SS. Finally, the results reveal a higher rate of degradation processes occurring in the SML than in the SS. Thus, the specific physical properties of surface active organic molecules (surfactants) may modify, in a specific way, the solar light spectrum entering the sea and a penetration depth of the solar radiation. Research on the influence of surfactants on the physical processes linked to the sea surface becomes an important task, especially in coastal waters and in the vicinity of the river mouths.

Studies of aerosol particle number concentration (PNC) level over open sea in the southern and south-eastern Baltic Sea regions were performed during five cruises (2005–2006, 2008–2010) by RV Oceania and at the coastal Preila station (Lithuania). A comparative analysis was performed of aerosol PNC variation at open sea versus measurements taken at the coastal site under various conditions (breaking waves, fog events, NPF), considering transport of forest fire products and advection of different air mass types to the investigation sites. It was found that the average PNC over the open sea (3000–4000 cm− 3) was generally higher than at the coastal site (2000–3000 cm− 3). Breaking waves caused by the latitudinal or longitudinal long-lasting (3–4 days) constant-direction wind under stormy conditions had the strongest effect on the aerosol PNC over the Baltic Sea. The aerosol PNC in the marine boundary layer (MBL) of the south-eastern Baltic Sea during fog did not depend on the air mass type over open sea, in contrast to the coastal site, that is, the average PNC level (3000–4000 cm− 3) in the MBL, which could be constantly affected by specific environmental factors as a source of condensation nuclei for the fog formation. Short-term increases of aerosol PNC in the MBL (5000–10,000 cm− 3) were higher than in the same periods of the time scale at the coastal site (3000–6000 cm− 3) during NPF events, and therefore the open sea environment may facilitate a more favourable condition for the NPF, that is, exhaust and biogenic emissions from ships and the marine environment.

This paper is focused on Saharan dust transport to Central Europe/Poland; we compare properties of atmospheric Saharan dust using data from NAAPS, MACC, AERONET as well as observations obtained during HyMountEcos campaign in June 2012. Ten years of dust climatology shows that long-range transport of Saharan dust to Central Europe is mostly during spring and summer. HYSPLIT back-trajectories indicate airmass transport mainly in November, but it does not agree with modeled maxima of dust optical depth. NAAPS model shows maximum of dust optical depth (~0.04–0.05, 550 nm) in April–May, but the MACC modeled peak is broader (~0.04). During occurrence of mineral dust over Central-Europe for 14% (NAAPS) / 12% (MACC) of days dust optical depths are above 0.05 and during 4% (NAAPS) / 2.5% (MACC) of days dust optical depths exceed 0.1. The HyMountEcos campaign took place in June–July 2012 in the mountainous region of Karkonosze. The analysis includes remote sensing data from lidars, sunphotometers, and numerical simulations from NAAPS, MACC, DREAM8b models. Comparison of simulations with observations demonstrates the ability of models to reasonably reproduce aerosol vertical distributions and their temporal variability. However, significant differences between simulated and measured AODs were found. The best agreement was achieved for MACC model.

We analysed δ13C of total carbon (TC) and δ15N of total nitrogen (TN) in submicron (PM1) and size segregated aerosol particles (PM0.056–2.5) collected during a cruise in the Baltic Sea from 9 to 17 November 2012. PM1 were characterized by the highest δ13C (–26.4‰) and lowest δ15N (–0.2 and 0.8‰) values when air masses arrived from the southwest direction (Poland). The obtained δ13C values indicated that combined emissions of coal and diesel/gasoline combustion were the most likely sources of TC. The depleted δ15N values indicated that TN originated mainly from liquid fuel combustion (road traffic, shipping) during this period. The lowest δ13C and highest δ15N values were determined in PM1 samples during the western airflow when the air masses had no recent contact with land. The highest δ15N values were probably associated with chemical aging of nitrogenous species during long-range transport, the lowest δ13C values could be related to emissions from diesel/gasoline combustion, potentially from ship traffic. The δ13C analysis of size-segregated aerosol particles PM0.056–2.5 revealed that the lowest δ13C values were observed in the size range from 0.056 to 0.18 µm and gradual 13C enrichment occurred in the size range from 0.18 to 2.5 µm due to different sources or formation mechanisms of the aerosols.

The subject of this study is to use in-situ measurements, passive and active remote sensing observations, as well as numerical simulations to describe the temporal variability of aerosol single-scattering properties such as aerosol optical depth (AOD), single scattering albedo (SSA), and aerosol direct shortwave forcing at the Earth׳s surface during the transport of biomass burning (BB) aerosols from Canada to Europe between 2nd and 7th of July 2013. According to the MODIS observations made in the IR spectrum, an area of over 200,000 km 2 was affected by the BB during the episode. Regarding the AERONET data in Canada, results show a significant variability of AOD within the whole period with a special enhancement between 6th and 9th July, when AOD anomaly led to an increase up to 1.5 (500 nm). Low-values of SSA reported at Yellowknife Aurora and Waskesiu are likely to be due to flaming combustion from closely located source areas. MODIS and CALIPSO observations, as well as numerical simulations of the NAAPS model, show transport of smoke particles over the Northern Atlantic Ocean and further eastward. Indeed, the event was observed at a different times and locations over Europe between 2nd and 14th July. During that period a number of AERONET stations, mainly located close to the Baltic Sea reported AOD at 500 nm of above 1. Compared to Canada the SSA in Europe was higher, indicating particle transformation over the Atlantic Ocean. Lidar observations in the northern Poland showed aerosol layers occurring between PBL height and tropopause with a significant (up to 55%) contribution to the total AOD. However, lidar measurements in Central Poland (Warsaw and Belsk) indicate that aerosols were confined mainly in the middle and lower troposphere. A diurnal mean aerosol direct radiative forcing estimated at the ground level during the event was below −30 W/m 2 with radiative forcing efficiency between −60 and −100 W/m 2 /τ 500. The strongest efficiency was found at the Strzyzow station, which was caused by further air mass transformation during its transport over Poland.

This paper presents the results of measurements of aerosol physical and chemical properties during iAREA2014 campaign that took place on Svalbard between 15th of Mar and 4th of May 2014. With respect to field area, the experiment consisted of two sites: NyeAlesund (78�550N, 11�560E) and Longyearbyen (78�130N, 15�330E) with further integration of Aerosol Robotic Network (AERONET) station in Hornsund (77�000N, 15�330E). The subject of this study is to investigate the inesitu, passive and active remote sensing observations as well as numerical simulations to describe the temporal variability of aerosol singleescattering properties during spring season on Spitsbergen. The retrieval of the data indicates several event days with enhanced singleescattering properties due to the existence of sulphate and additional seaesalt load in the atmosphere which is possibly caused by relatively high wind speed. Optical results were confirmed by numerical simulations made by the GEMeAQ model and by chemical observations that indicated up to 45% contribution of the seaesalt to a PM10 total aerosol mass concentration. An agreement between the in-situ optical and microphysical properties was found, namely: the positive correlation between aerosol scattering coefficient measured by the nephelometer and effective radius obtained from laser aerosol spectrometer as well as negative correlation between aerosol scattering coefficient and the Angstrom exponent indicated that slightly larger particles dominated during special events. The inesitu surface observations do not show any significant enhancement of the absorption coefficient as well as the black carbon concentration which might occur during spring. All of extensive singleescattering properties indicate a diurnal cycle in Longyearbyen, where 21:00e5:00 data stays at the background level, however increasing during the day by the factor of 3e4. It is considered to be highly connected with local emissions originating in combustion, traffic and harbour activities. On the other hand, no daily fluctuations in NyeAlesund are observed. Mean values in NyeAlesund are equal to 8.2, 0.8 Mm�1 and 103 ng/m3 for scattering, absorption coefficients and black carbon concentration; however in Longyearbyen (only data from 21:00e05:00 UTC) they reach 7.9, 0.6 Mm�1 as well as 83 ng/ m3 respectively. Overall, the spring 2014 was considerably clean and seaesalt was the major aerosol component

The results of studies of the vertical gradient of aerosol concentration measurements made during cruises of r/v ‘Oceania’ between 2008 and 2012 are presented. Using the results from those experiments, sea spray emission fluxes were calculated for all particles of sizes in the range from 0.5 μm to 8 μm, as well as for particles of sizes from fifteen channels of 0.5 μm width. The information obtained was further used to calculate the Sea Salt Generation Function (SSGF) for the Baltic Sea depending on the wind speed and the aerosol size distribution.

During the summers of 2011 and 2012, two scientific cruises were carried out over the Arctic Ocean aiming at the determination of the aerosol chemical composition in this pristine environment. First, mass spectrometry was applied to study the concentration and gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. Experimental and modelled data of phase partitioning were compared: results demonstrated an equilibrium between gas and particle phase for PAHs, while n-alkanes showed a particle-oriented partitioning, due to the local marine origin of them, confirmed by the extremely low value of their carbon preference index. Moreover, the inorganic and organic ions (carboxylic acids and amines) concentrations, together with those of elemental carbon (EC) and organic matter (OM), were analyzed: 63% of aerosol was composed of ionic compounds (&gt, 90% from sea-salt) and the OM content was very high (30.5%, close to 29.0% of Cl&minus, ) in agreement with n-alkanes&rsquo, marine signature. Furthermore, the amines&rsquo, (dimethylamine, trimethylamine, diethylamine) concentrations were 3.98 &plusmn, 1.21, 1.70 &plusmn, 0.82, and 1.06 &plusmn, 0.56 p.p.t.v., respectively, fully in keeping with concentration values used in the CLOUD (Cosmics Leaving OUtdoor Droplet)-chamber experiments to simulate the ambient nucleation rate in a H2SO4-DMA-H2O system, showing the amines&rsquo, importance in polar regions to promote new particle formation. Finally, high resolution mass spectrometry was applied to determine trace elements, including Rare Earth Elements (REEs), highlighting the dominant natural versus anthropic inputs for trace metals (e.g., Fe, Mn, Ti vs. As, Cd, Ni) and possible signatures of such anthropic activity.

In this paper we describe the results of a research campaign dedicated to the studies of aerosol optical properties in different regions of both the open Baltic Sea and its coastal areas. During the campaign we carried out simultaneous measurements of aerosol optical depth at 4 stations with the use of the hand-held Microtops II sun photometers. The studies were complemented with aerosol data provided by the MODIS. In order to obtain the full picture of aerosol situation over the study area, we added to our analyses the air mass back-trajectories at various altitudes as well as wind fields. Such complex information facilitated proper conclusions regarding aerosol optical depth and Angstrom exponent for the four locations and discussion of the changes of aerosol properties with distance and with changes of meteorological factors. We also show that the Microtops II sun photometers are reliable instruments for field campaigns. They are easy to operate and provide good quality results.

In this work multi wavelength Raman lidar data from Ny-Ålesund, Spitsbergen have been analysed for the spring 2014 Arctic haze season, as part of the iAREA campaign. Typical values and probability distributions for aerosol backscatter, extinction and depolarisation, the lidar ratio and the color ratio for 4 different altitude intervals within the troposphere are given. These quantities and their dependencies are analysed and the frequency of altitude-dependent observed aerosol events are given. A comparison with ground-based size distribution and chemical composition is performed. Hence the aim of this paper is to provide typical and statistically meaningful properties of Arctic aerosol, which may be used in climate models or to constrain the radiative forcing. We have found that the 2014 season was only moderately polluted with Arctic haze and that sea salt and sulphate were the most dominant aerosol species. Moreover the drying of an aerosol layer after cloud disintegration has been observed. Hardly any clear temporal evolution over the 4 week data set on Arctic haze is obvious with the exception of the extinction coefficient and the lidar ratio, which significantly decreased below 2 km altitude by end April. In altitudes between 2 and 5 km the haze season lasted longer and the aerosol properties were generally more homogeneous than closer to the surface. Above 5 km only few particles were found. The variability of the lidar ratio is discussed. It was found that knowledge of the aerosol’s size and shape does not determine the lidar ratio. Contrary to shape and lidar ratio, there is a clear correlation between size and backscatter: larger particles show a higher backscatter coefficient.

This work provides information on selected optical parameters related to volcanic ash produced during the eruption of the Eyjafjoll volcano in Iceland in 2010. The observations were made between 16 and 18 April 2010 at four stations representative for northern (Sopot), central (Warsaw, Belsk) and south-eastern (Strzyzow) regions of Poland. The largest ash plume (in terms of aerosol optical thickness) over Poland was observed at night of 16/17 April 2010 in the layer between 4 and 5.5 km a.s.l. The highest values of the aerosol extinction coefficient reached 0.06e0.08 km � 1 at 532 nm (based on lidar observations in Warsaw) and 0.02e0.04 km � 1 at 1064 nm (based on ceilometer observations in Warsaw). The corresponding optical thickness due to volcanic ash reached values of about 0.05 at 532 nm and about 0.03 at 1064 nm. These values are similar to those reported for the Belsk station based on lidar observations. The ash mass concentration estimated based on the maximum aerosol extinction coefficient reached 0.22 � 0.11 mg m � 3 . This value is significantly lower than the limit (2 mg m � 3 ) for the aircraft operation.

This paper presents the results of the studies of aerosol optical properties measured using lidars and sun photometers. We describe two case studies of the combined measurements made in two coastal zones in Crete in 2006 and in Rozewie on the Baltic Sea in 2009. The combination of lidar and sun photometer measurements provides comprehensive information on both the total aerosol optical thickness in the entire atmosphere as well as the vertical structure of aerosol optical properties. Combination of such information with air mass back-trajectories and data collected at stations located on the route of air masses provides complete picture of the aerosol variations in the study area both vertically and horizontally. We show that such combined studies are especially important in the coastal areas where depending on air mass advection directions and altitudes the influence of fine or coarse mode (in this case possibly sea-salt) particles on the vertical structure of aerosol optical properties is an important issue to consider.

In this work we present the annual changes of two major, climate related aerosol optical parameters measured at three Spitsbergen locations, Ny-Alesund, Longyearbyen and Hornsund over a period between 2000 and 2012. We discuss the changes of aerosol optical depth (AOD) at 500 nm and the Angstrom exponent (AE) (440–870 nm) measured with use of different types of sun photometers. For the measurement data we adopted several data quality assurance techniques and the calibration of the instruments was taken into consideration. The results obtained show that marine source has been a dominating of aerosol sources over Spitsbergen. Some years (2005, 2006, 2008 and 2011) show very high values of AOD due to strong aerosol events such as the Arctic Haze. In general the mean AOD values increase over the period of 2000 and 2012 over Spitsbergen. This may indicate the presence of larger scale of atmospheric pollution in the region.

Aerosols measured in coastal areas are significantly different from those over an open sea, both in terms of structure and physical properties. The aerosol composition and concentrations are generally uniform in the open sea area. In the case of coastal areas, the composition may be changed within a short period of time. Aerosols in coastal zone can be divided into three groups: the sea, a mixture of continental and maritime, and continental. This chapter describes the most representative day of a research campaign designed to characterize the optical properties of aerosols in the Baltic Sea (open sea and coastal areas). During the campaign, simultaneous measurements of aerosol optical depth were carried out at four stations around the Baltic Sea—Bornholm, Sopot, Preila and Liepaja, using the hand-held Microtops II sun photometers. The studies were supplemented with satellite data (MODIS) and the analysis of air mass back-trajectories at various altitudes and wind fields. Measurements were performed at four stations. Simultaneous measurements at these stations with use of Microtops sun photometer can provide important information on the aerosol optical depth (AOD) and hence on the radiation balance. Data obtained with Microtops complement well with those obtained from MODIS. Using wind field profiles we possibly detected sea surface impact on aerosol concentrations in Bornholm, where on 3 August 2011 the AOD was significantly greater, along with a strong onshore winds.

Properties of atmospheric aerosols and solar radiation reaching the Earth’s surface were measured during Summer 2011 in Sopot, Poland. Three cloudless days, characterized by different directions of incoming air-flows, which are typical transport pathways to Sopot, were used to estimate a radiative forcing due to aerosols present in each air mass.

Multiwavelength micropulse lidar (MML) designed for continuous optical sounding of the atmosphere is presented. A specific signal processing technique applying two directional Kalman filtering is introduced in order to enhance signal to noise ratio. Application of this technique is illustrated with profiles collected in course of COAST 2009 and WRNP 2010 research campaigns.

Summary In this paper the authors discuss the changes of aerosol optical depth (AOD) in the region of eastern Europe and the Baltic Sea due to wild fire episodes which occurred in the area of Belarus and Ukraine in 2002. The authors discuss how the biomass burning aerosols were advected over the Baltic area and changed the composition of aerosol ensemble for a period of several summer weeks. The air pressure situation and slow wind speeds also facilitated the development of such conditions. As a consequence very high AOD levels were recorded, by an order of 3–4 higher versus normal conditions and they significantly increased the annual averages. On particular days of August 2002 the AOD values reached a level of over 0.7. On these days fine particles fully dominated the entire ensemble of aerosol particles. They were either sulfates or smoke particles. Such situation was unique over a period of many years and it had its serious consequences for the region and especially for the Baltic Sea.