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20-Year Climatology of and Wet Deposition at Ny-lcurlyb\AArcurlyblesund, Svalbard  [PDF]
Rafael Kühnel,Tjarda J. Roberts,Mats P. Bj?rkman,Elisabeth Isaksson,Wenche Aas,Kim Holmén,Johan Str?m
Advances in Meteorology , 2011, DOI: 10.1155/2011/406508
Abstract: A 20-year dataset of weekly precipitation observations in Ny-?lesund, Svalbard, was analysed to assess atmospheric wet deposition of nitrogen. Mean annual total nitrogen deposition was 74?mg?N/(m2?yr) but exhibited large interannual variability and was dominated by highly episodic “strong” events, probably caused by rapid transport from European sources. The majority (90%) of precipitation samples were defined as “weak” (<2?mg?N/m2) and contributed an annual baseline of ~17?mg?N/(m2?yr), whereas 10% of precipitation samples were defined as “strong” (>2?mg?N/m2) and additionally contributed up to 225?mg?N/(m2?yr). Nitrate deposition largely occurred in samples within the solid-precipitation season (16 September–2 June), and ammonium deposition occurred equally in both solid and liquid seasons. Trends of reactive nitrogen emissions from Europe are uncertain, and increasing cyclonic activity over the North Atlantic caused by a changing climate might lead to more strong deposition events in Svalbard. 1. Introduction Human activities release reactive nitrogen such as NH3 and (NO + NO2) to the atmosphere through energy production, fertilizer production, and cultivation of crops [1–4]. The resulting nitrogen-enriched air masses can be transported into remote, nutrient-limited regions such as the Arctic [5], primarily in the form of PAN (peroxyacetyl nitrate), but also as nitrate and ammonium aerosol. Furthermore, deposition of reactive nitrogen through precipitation is considered to be the main pathway for transfer of atmospheric nitrogen to the high Arctic surface [6]. The deposition of reactive nitrogen in the Arctic therefore results from the complex interplay of emissions, atmospheric transport, chemistry, precipitation, and snowpack processes as described below. Ice core analyses from Svalbard [7] and Greenland [8] showed an increase in nitrate concentrations in the 1950’s, followed by a drop in the 1980’s in the Svalbard ice cores. A trend analysis of recent precipitation observations in Europe could not find any significant trends for nitrate in Ny-?lesund [9, 10]. In Europe and North America, the nitrogen emissions are expected to further decrease due to current and future legislations though there are regional differences which may affect the Arctic in particular. The expected intensification of shipping activity might lead to an increase of nitrogen emissions in the Arctic [4]. Reduction protocols and improvements in technology counteract the increase of nitrogen emissions, and some progress has been made in reducing emissions in the last decade [11,
20-Year Climatology of and Wet Deposition at Ny-lcurlyb\AArcurlyblesund, Svalbard  [PDF]
Rafael Kühnel,Tjarda J. Roberts,Mats P. Bj rkman,Elisabeth Isaksson,Wenche Aas,Kim Holmén,Johan Str m
Advances in Meteorology , 2011, DOI: 10.1155/2011/406508
Abstract: A 20-year dataset of weekly precipitation observations in Ny-Ålesund, Svalbard, was analysed to assess atmospheric wet deposition of nitrogen. Mean annual total nitrogen deposition was 74 mg N/(m2 yr) but exhibited large interannual variability and was dominated by highly episodic “strong” events, probably caused by rapid transport from European sources. The majority (90%) of precipitation samples were defined as “weak” (<2 mg N/m2) and contributed an annual baseline of ~17 mg N/(m2 yr), whereas 10% of precipitation samples were defined as “strong” (>2 mg N/m2) and additionally contributed up to 225 mg N/(m2 yr). Nitrate deposition largely occurred in samples within the solid-precipitation season (16 September–2 June), and ammonium deposition occurred equally in both solid and liquid seasons. Trends of reactive nitrogen emissions from Europe are uncertain, and increasing cyclonic activity over the North Atlantic caused by a changing climate might lead to more strong deposition events in Svalbard.
Climatology and time series of surface meteorology in Ny- lesund, Svalbard
M. Maturilli, A. Herber,G. K nig-Langlo
Earth System Science Data (ESSD) & Discussions (ESSDD) , 2013, DOI: 10.5194/essd-5-155-2013
Abstract: A consistent meteorological dataset of the Arctic site Ny- lesund (11.9° E, 78.9° N) spanning the 18 yr-period 1 August 1993 to 31 July 2011 is presented. Instrumentation and data handling of temperature, humidity, wind and pressure measurements are described in detail. Monthly mean values are shown for all years to illustrate the interannual variability of the different parameters. Climatological mean values are given for temperature, humidity and pressure. From the climatological dataset, we also present the time series of annual mean temperature and humidity, revealing a temperature increase of +1.35 K per decade and an increase in water vapor mixing ratio of +0.22 g kg 1 per decade for the given time period, respectively. With the continuation of the presented measurements, the Ny- lesund high resolution time series will provide a reliable source to monitor Arctic change and retrieve trends in the future. The relevant data are provided in high temporal resolution as averages over 5 (1) min before (after) 14 July 1998, respectively, placed on the PANGAEA repository (doi:10.1594/PANGAEA.793046). While 6 hourly synoptic observations in Ny- lesund by the Norwegian Meteorological Institute reach back to 1974 (F rland et al., 2011), the meteorological data presented here cover a shorter time period, but their high temporal resolution will be of value for atmospheric process studies on shorter time scales.
Climatology and time series of surface meteorology in Ny- lesund, Svalbard  [PDF]
M. Maturilli,A. Herber,G. K?nig-Langlo
Earth System Science Data Discussions , 2012, DOI: 10.5194/essdd-5-1057-2012
Abstract: A consistent meteorological dataset of the Arctic site Ny- lesund (11.9° E, 78.9° N) spanning the 18-yr-period 1 August 1993 to 31 July 2011 is presented. Instrumentation and data handling of temperature, humidity, wind and pressure measurements are described in detail. Monthly mean values are shown for all years to illustrate the interannual variablity of the different parameter. Climatological mean values are given for temperature, humidity and pressure. From the climatological dataset, we also present the time series of annual mean temperature and humidity, revealing a temperature increase of +1.35 K per decade and an increase in water vapor mixing ratio of +0.22 g kg 1 per decade for the given time period, respectively. With the continuation of the presented measurements, the Ny- lesund high resolution time series will provide a reliable source to monitor Arctic change and retrieve trends in the future. The relevant data are provided in high temporal resolution as averages over 5 [1] min before [after] 14 July 1998, respectively, placed on the PANGAEA repository (http://doi.pangaea.de/10.1594/PANGAEA.793046). While synoptic observations by the Norwegian Meteorological Institute reach back to 1935 (F rland et al., 2011), the meteorological data presented here cover a shorter time period, but their high temporal resolution will be of value for atmospheric process studies on shorter time scales.
Reactive nitrogen and sulphate wet deposition at Zeppelin Station, Ny- lesund, Svalbard
Rafael Kühnel,Mats P. Bj?rkman,Carmen P. Vega,Andy Hodson
Polar Research , 2013, DOI: 10.3402/polar.v32i0.19136
Abstract: As a potent fertilizer, reactive nitrogen plays an important role in Arctic ecosystems. Since the Arctic is a nutrient-limited environment, changes in nitrogen deposition can have severe impacts on local ecosystems. To quantify the amount of nitrogen deposited through snow and rain events, precipitation sampling was performed at Zeppelin Station, Svalbard, from November 2009 until May 2011. The samples were analysed for , nss- and concentrations, and the deposition of single precipitation events was calculated using precipitation measurements taken at nearby Ny- lesund. The majority of observed events showed concentrations ranging from 0.01 to 0.1 mg L 1 N for and and from 0.02 to 0.3 mg L 1 S for nss-. The majority of calculated depositions ranged from 0.01 to 0.1 mg m 2 N for and and from 0.02 to 0.3 mg m 2 S for nss-. The budget was controlled by strong deposition events, caused by long-lasting precipitation episodes that lasted for several days and which had raised concentrations of nitrogen and sulphur. Three future scenarios of increasing precipitation in the Arctic were considered. The results showed that deposition is mainly controlled by the amount of precipitation, which leads to the conclusion that increased precipitation might cause increases in deposition of the same magnitude.
Arctic aerosol life cycle: linking aerosol size distributions observed between 2000 and 2010 with air mass transport and precipitation at Zeppelin station, Ny- lesund, Svalbard  [PDF]
P. Tunved,J. Str?m,R. Krejci
Atmospheric Chemistry and Physics Discussions , 2012, DOI: 10.5194/acpd-12-29967-2012
Abstract: In this study we present a qualitative and quantitative assessment of more the 10 yr of aerosol number size distribution data observed in the Arctic environment (Mt Zeppelin (78°56' N, 11°53' E, 474 m a.s.l.), Ny lesund, Svalbard). We provide statistics on both seasonal and diurnal characteristics of the aerosol observations and conclude that the Arctic aerosol number size distribution and auxiliary parameters such as integral mass and surface have a very pronounced seasonal variation. This seasonal variation seems to be controlled by both dominating source as well as meteorological conditions in general. In principle, three distinctly different periods can be identified during the Arctic year: the haze period characterized by a dominating accumulation mode aerosol (March–May) followed by the sunlit summer period with low abundance of accumulation mode particles but high concentration of small particles which likely are recently and locally formed (June–August). The rest of the year is characterized by comparably low concentration of accumulation mode particles and negligible abundance of ultra fine particles (September–February). Minimum aerosol mass and number concentration is usually observed during September/October. We further show that the transition between the different regimes is fast, suggesting rapid change in conditions defining their appearance. A source climatology based on trajectory analysis is provided and it is shown that there is a strong seasonality of dominating source areas, with dominance of Eurasia during the autumn-winter period and dominance of North Atlantic air during the summer months. We also show that new particle formation events seem to be a rather common phenomenon during the Arctic summer, and this is the result of both photochemical production of nucleating/condensing species and low condensation sink. It is also suggested that wet removal play a key role in defining the Arctic aerosol year, and plays a crucial role for removal of accumulation mode size particles as well as it may play a pivotal role for facilitating the conditions favoring new particle formation events. In summary the aerosol Arctic year seems to be at least qualitatively predictable based on knowledge of seasonality of transport paths and associated source areas, meteorological conditions and removal processes.
Arctic aerosol life cycle: linking aerosol size distributions observed between 2000 and 2010 with air mass transport and precipitation at Zeppelin station, Ny- lesund, Svalbard  [PDF]
P. Tunved,J. Str?m,R. Krejci
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2013, DOI: 10.5194/acp-13-3643-2013
Abstract: In this study we present a qualitative and quantitative assessment of more than 10 yr of aerosol number size distribution data observed in the Arctic environment (Mt. Zeppelin (78°56' N, 11°53' E, 474 m a.s.l.), Ny lesund, Svalbard). We provide statistics on both seasonal and diurnal characteristics of the aerosol observations and conclude that the Arctic aerosol number size distribution and related parameters such as integral mass and surface area exhibit a very pronounced seasonal variation. This seasonal variation seems to be controlled by both dominating source as well as meteorological conditions. Three distinctly different periods can be identified during the Arctic year: the haze period characterized by a dominating accumulation mode aerosol (March–May), followed by the sunlit summer period with low abundance of accumulation mode particles but high concentration of small particles which are likely to be recently and locally formed (June–August). The rest of the year is characterized by a comparably low concentration of accumulation mode particles and negligible abundance of ultrafine particles (September–February). A minimum in aerosol mass and number concentration is usually observed during September/October. We further show that the transition between the different regimes is fast, suggesting rapid change in the conditions defining their appearance. A source climatology based on trajectory analysis is provided, and it is shown that there is a strong seasonality of dominating source areas, with Eurasia dominating during the Autumn–Winter period and dominance of North Atlantic air during the summer months. We also show that new-particle formation events are rather common phenomena in the Arctic during summer, and this is the result of photochemical production of nucleating/condensing species in combination with low condensation sink. It is also suggested that wet removal may play a key role in defining the Arctic aerosol year, via the removal of accumulation mode size particles, which in turn have a pivotal role in facilitating the conditions favorable for new-particle formation events. In summary the aerosol Arctic year seems to be at least qualitatively predictable based on the knowledge of seasonality of transport paths and associated source areas, meteorological conditions and removal processes.
Nitrate dry deposition in Svalbard
Mats P. Bj?rkman,Rafael Kühnel,Daniel G. Partridge,Tjarda J. Roberts
Tellus B , 2013, DOI: 10.3402/tellusb.v65i0.19071
Abstract: Arctic regions are generally nutrient limited, receiving an extensive part of their bio-available nitrogen from the deposition of atmospheric reactive nitrogen. Reactive nitrogen oxides, as nitric acid (HNO3) and nitrate aerosols (p-NO3), can either be washed out from the atmosphere by precipitation or dry deposited, dissolving to nitrate (NO3-). During winter, NO3- is accumulated in the snowpack and released as a pulse during spring melt. Quantification of NO3- deposition is essential to assess impacts on Arctic terrestrial ecology and for ice core interpretations. However, the individual importance of wet and dry deposition is poorly quantified in the high Arctic regions where in-situ measurements are demanding. In this study, three different methods are employed to quantify NO3- dry deposition around the atmospheric and ecosystem monitoring site, Ny- lesund, Svalbard, for the winter season (September 2009 to May 2010): (1) A snow tray sampling approach indicates a dry deposition of –10.27±3.84 mg m 2 (± S.E.); (2) A glacial sampling approach yielded somewhat higher values –30.68±12.00 mg m 2; and (3) Dry deposition was also modelled for HNO3 and p-NO3 using atmospheric concentrations and stability observations, resulting in a total combined nitrate dry deposition of –10.76±1.26 mg m 2. The model indicates that deposition primarily occurs via HNO3 with only a minor contribution by p-NO3. Modelled median deposition velocities largely explain this difference: 0.63 cm s 1 for HNO3 while p-NO3 was 0.0025 and 0.16 cm s 1 for particle sizes 0.7 and 7 μm, respectively. Overall, the three methods are within two standard errors agreement, attributing an average 14% (total range of 2–44%) of the total nitrate deposition to dry deposition. Dry deposition events were identified in association with elevated atmospheric concentrations, corroborating recent studies that identified episodes of rapid pollution transport and deposition to the Arctic.
Climatology of aerosol optical properties in Northern Norway and Svalbard
Y.-C. Chen,B. Hamre,? Frette,J. J. Stamnes
Atmospheric Measurement Techniques Discussions , 2012, DOI: 10.5194/amtd-5-7619-2012
Abstract: We present comparisons between estimates of the aerosol optical thickness and the ngstr m exponent in Northern Norway and Svalbard based on data from AERONET stations at Andenes (69° N, 16° E, 379 m altitude) and Hornsund (77° N, 15° E, 10 m altitude) for the period 2008–2010. The three-year annual mean values for the aerosol optical thickness at 500 nm τ(500) at Andenes and Hornsund were 0.11 and 0.10, respectively. At Hornsund, there was less variation of the monthly mean value of τ(500) than at Andenes. The annual mean values of the ngstr m exponent α at Andenes and Hornsund were 1.18 and 1.37, respectively. At Andenes and Hornsund α was found to be larger than 1.0 in 68% and 93% of the observations, respectively, indicating that fine-mode particles were dominating at both sites. Both sites had a similar seasonal variation of the aerosol size distribution although one site is in an Arctic area while the other site is in a sub-arctic area.
Properties of aerosols and their wet deposition in the arctic spring during ASTAR2004 at Ny-Alesund, Svalbard
S. Yamagata, D. Kobayashi, S. Ohta, N. Murao, M. Shiobara, M. Wada, M. Yabuki, H. Konishi,T. Yamanouchi
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2009,
Abstract: During the period of scientific campaign "Arctic Study of Tropospheric Aerosols, Clouds and Radiation 2004" (ASTAR2004), precipitation samples were collected in late spring at Ny-Alesund, Svalbard and their ionic components were analyzed in parallel with the measurement of properties of atmospheric aerosol particles at the same place. Backward trajectory analyses indicated that the air mass above the observatory initially dominated by air masses from the Arctic Ocean, then those from western Siberia and later those from Greenland and the Arctic Ocean. In the measurement period, six precipitation samples were obtained and five of them were analyzed their ionic components by ionchromatography. The concentrations of nss-sulphate in precipitations were between 1.8 and 24.6 ppm from which the scavenging ratio and scavenging coefficients were calculated using the data such as the concentrations of nss-sulphate in aerosol particles, amounts of precipitations, and the heights of precipitations obtained from radar echo data. The scavenging ratio ranged from 1.0×106 to 17×106 which are comparable values reported in other areas. A detailed comparison between precipitation events and the number concentration of aerosol particles obtained from optical particle counters suggests that the type of precipitations, i.e. rain or snow, significantly affects the number concentrations of aerosol particles.
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