The dynamic effects of sediment availability on the relationship between wind speed and dust concentration

Where sediment supply is unlimited, previous research suggests that a strong, positive relationship between wind speed and dust concentration exists at the event‐scale. This relationship can break down if sediment availability is limited or changes during an event. This paper explores the dynamic effects of sediment availability on the relationship between wind speed and dust concentration using data from 9 high‐latitude dust events recorded in Iceland. Of these events, 6 showed a strong positive relationship between wind speed and dust concentration. For the remainder, the relationship breaks down periodically during the event due to changing surface moisture conditions and atmospheric humidity. Results suggest a need to understand how spatial and temporal changes in humidity, surface soil moisture, soil texture and threshold velocity interact and control sediment availability for dust emissions in all environments, including at high latitudes

Protect Me from What I Want: Understanding Excessive Polluting Behavior and the Willingness to Act

Publisher's version (útgefin grein)Many environmental problems stem from unsustainable human consumption. Accordingly, many studies have focused on the barriers to pro-environmental behavior. The inability or unwillingness to act is partially related to personal values as well as the psychological distance between individual actions and the resulting pollution, which is often perceived as abstract or intangible. In contrast, fireworks produce imminent, undeniable air pollution. The goal of this research was to advance the knowledge on the awareness-value-behavior gap by studying public fireworks consumption and the willingness to act against firework pollution. A nationally representative survey was conducted after the extremely polluting 2017/18 New Year's Eve in Iceland (European hourly record in fine particulate matter: 3014 μg/m3). Our results demonstrate that, after controlling for the awareness of harmful pollution, hedonic motives predict the purchasing of fireworks and the opposition to mitigating action. Noticing public warnings regarding fireworks pollution did not significantly relate to the purchase behavior. The awareness of the harmful effects of firework pollution was, however, the largest predictor of the support for mitigating action. Despite reporting the pleasure derived from fireworks, 57% of the sample favored stricter governmental regulation, and 27% favored banning the public use of fireworks in order to "protect them from what they want".This research was funded by the Engineering Institute of the University of Iceland (P.I. Hrund Andradóttir).Peer Reviewe

Pathways of high-latitude dust in the North Atlantic

The contribution of mineral dust from high-latitude sources has remained an under-examined feature of the global dust cycle. Dust events originating at high latitudes can provide inputs of aeolian sediment to regions lying well outside the subtropical dust belt. Constraining the seasonal variability and preferential pathways of dust from high-latitude sources is important for understanding the potential impacts that the dust may have on wider environmental systems, such as nearby marine or cryospheric domains. This study quantifies dust pathways from two areas exhibiting different emission dynamics in the north and south of Iceland, which is a prominent Northern Hemisphere dust source. The analysis uses air parcel trajectory modelling, and for the first time for high-latitude sources, explicitly links all trajectory simulations to time-specific (meteorological) observations of suspended dust. This approach maximises the potential for trajectories to represent dust, and illustrates that trajectory climatologies not limited to dust can grossly overestimate the potential for dust transport. Preferential pathways emerge that demonstrate the role of Iceland in supplying dust to the Northern Atlantic and sub-Arctic oceans. For dust emitted from northern sources, a dominant route exists to the northeast, into the Norwegian, Greenland and Barents Seas, although there is also potential for delivery to the North Atlantic in summer months. From the southern sources, the primary pathway extends into the North Atlantic, with a high density of trajectories extending as far south as 50ºN, particularly in spring and summer. Common to both southern and northern sources is a pathway to the west-southwest of Iceland into the Denmark Strait and towards Greenland. For trajectories simulated at ≤500 m, the vertical development of dust plumes from Iceland is limited, likely due to the stable air masses of the region suppressing the potential for vertical motion. Trajectories rarely ascend high enough to reach the central portions of the Greenland Ice Sheet. The overall distribution of trajectories suggests that contributions of Icelandic dust are relatively more important for neighbouring marine environments than the cryosphere

Protect Me from What I Want: Understanding Excessive Polluting Behavior and the Willingness to Act

This research was funded by the Engineering Institute of the University of Iceland (P.I. Hrund Andradóttir).Many environmental problems stem from unsustainable human consumption. Accordingly, many studies have focused on the barriers to pro-environmental behavior. The inability or unwillingness to act is partially related to personal values as well as the psychological distance between individual actions and the resulting pollution, which is often perceived as abstract or intangible. In contrast, fireworks produce imminent, undeniable air pollution. The goal of this research was to advance the knowledge on the awareness-value-behavior gap by studying public fireworks consumption and the willingness to act against firework pollution. A nationally representative survey was conducted after the extremely polluting 2017/18 New Year's Eve in Iceland (European hourly record in fine particulate matter: 3014 μg/m3). Our results demonstrate that, after controlling for the awareness of harmful pollution, hedonic motives predict the purchasing of fireworks and the opposition to mitigating action. Noticing public warnings regarding fireworks pollution did not significantly relate to the purchase behavior. The awareness of the harmful effects of firework pollution was, however, the largest predictor of the support for mitigating action. Despite reporting the pleasure derived from fireworks, 57% of the sample favored stricter governmental regulation, and 27% favored banning the public use of fireworks in order to "protect them from what they want".Peer reviewe

Emergency hospital visits in association with volcanic ash, dust storms and other sources of ambient particles: a time-series study in Reykjavík, Iceland.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Volcanic ash contributed significantly to particulate matter (PM) in Iceland following the eruptions in Eyjafjallajökull 2010 and Grímsvötn 2011. This study aimed to investigate the association between different PM sources and emergency hospital visits for cardiorespiratory causes from 2007 to 2012. Indicators of PM10 sources; "volcanic ash", "dust storms", or "other sources" (traffic, fireworks, and re-suspension) on days when PM10 exceeded the daily air quality guideline value of 50 µg/m3 were entered into generalized additive models, adjusted for weather, time trend and co-pollutants. The average number of daily emergency hospital visits was 10.5. PM10 exceeded the air quality guideline value 115 out of 2191 days; 20 days due to volcanic ash, 14 due to dust storms (two days had both dust storm and ash contribution) and 83 due to other sources. High PM10 levels from volcanic ash tended to be significantly associated with the emergency hospital visits; estimates ranged from 4.8% (95% Confidence Interval (CI): 0.6, 9.2%) per day of exposure in unadjusted models to 7.3% (95% CI: -0.4, 15.5%) in adjusted models. Dust storms were not consistently associated with daily emergency hospital visits and other sources tended to show a negative association. We found some evidence indicating that volcanic ash particles were more harmful than particles from other sources, but the results were inconclusive and should be interpreted with caution.Icelandic Centre for Research PhD fun

Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland

Deposition of small amounts of airborne dust on glaciers causes positive radiative forcing and enhanced melting due to the reduction of surface albedo. To study the effects of dust deposition on the mass balance of Brúarjökull, an outlet glacier of the largest ice cap in Iceland, Vatnajökull, a study of dust deposition events in the year 2012 was carried out. The dust-mobilisation module FLEXDUST was used to calculate spatio-temporally resolved dust emissions from Iceland and the dispersion model FLEXPART was used to simulate atmospheric dust dispersion and deposition. We used albedo measurements at two automatic weather stations on Brúarjökull to evaluate the dust impacts. Both stations are situated in the accumulation area of the glacier, but the lower station is close to the equilibrium line. For this site ( ∼  1210 m a.s.l.), the dispersion model produced 10 major dust deposition events and a total annual deposition of 20.5 g m−2. At the station located higher on the glacier ( ∼  1525 m a.s.l.), the model produced nine dust events, with one single event causing  ∼  5 g m−2 of dust deposition and a total deposition of  ∼  10 g m−2 yr−1. The main dust source was found to be the Dyngjusandur floodplain north of Vatnajökull; northerly winds prevailed 80 % of the time at the lower station when dust events occurred. In all of the simulated dust events, a corresponding albedo drop was observed at the weather stations. The influence of the dust on the albedo was estimated using the regional climate model HIRHAM5 to simulate the albedo of a clean glacier surface without dust. By comparing the measured albedo to the modelled albedo, we determine the influence of dust events on the snow albedo and the surface energy balance. We estimate that the dust deposition caused an additional 1.1 m w.e. (water equivalent) of snowmelt (or 42 % of the 2.8 m w.e. total melt) compared to a hypothetical clean glacier surface at the lower station, and 0.6 m w.e. more melt (or 38 % of the 1.6 m w.e. melt in total) at the station located further upglacier. Our findings show that dust has a strong influence on the mass balance of glaciers in Iceland.The study described in this manuscript was supported by NordForsk as part of the two Nordic Centres of Excellence Cryosphere-Atmosphere Interactions in a Changing Arctic climate (CRAICC), and eScience Tools for Investigating Climate Change (eSTICC). Part of this work was supported by the Centre of Excellence in Atmospheric Science funded by the Finnish Academy of Sciences Excellence (project no. 272041), by the Finnish Academy of Sciences project A4 (contract 254195). Data from in situ mass balance surveys and on glacier automatic weather stations are from joint projects of the National Power Company and the Glaciology group of the Institute of Earth Science, University of Iceland. C. Groot Zwaaftink was also funded by the Swiss National Science Foundation SNF (155294), and Louise Steffensen-Schmidt, Finnur Palsson and Sverrir Gudmunds-son by the Icelandic Research Fund (project SAMAR) and the National Power Company of Iceland. Olafur Arnalds was in part funded by Icelandic Research Fund (grant no. 152248-051)Peer Reviewe

Increased respiratory morbidity associated with exposure to a mature volcanic plume from a large Icelandic fissure eruption.

The 2014-15 Holuhraun eruption in Iceland was the largest fissure eruption in over 200 years, emitting prodigious amounts of gas and particulate matter into the troposphere. Reykjavík, the capital area of Iceland (250 km from eruption site) was exposed to air pollution events from advection of (i) a relatively young and chemically primitive volcanic plume with a high sulphur dioxide gas (SO2) to sulphate PM (SO42-) ratio, and (ii) an older and chemically mature volcanic plume with a low SO2/SO42- ratio. Whereas the advection and air pollution caused by the primitive plume were successfully forecast and forewarned in public advisories, the mature plume was not. Here, we show that exposure to the mature plume is associated with an increase in register-measured health care utilisation for respiratory disease by 23% (95% CI 19.7-27.4%) and for asthma medication dispensing by 19.3% (95% CI 9.6-29.1%). Absence of public advisories is associated with increases in visits to primary care medical doctors and to the hospital emergency department. We recommend that operational response to volcanic air pollution considers both primitive and mature types of plumes

Insulation effects of Icelandic dust and volcanic ash on snow and ice

In the Arctic region, Iceland is an important source of dust due to ash production from volcanic eruptions. In addition, dust is resuspended from the surface into the atmosphere as several dust storms occur each year. During volcanic eruptions and dust storms, material is deposited on the glaciers where it influences their energy balance. The effects of deposited volcanic ash on ice and snow melt were examined using laboratory and outdoor experiments. These experiments were made during the snow melt period using two different ash grain sizes (1 phi and 3.5 phi) from the Eyjafjallajokull 2010 eruption, collected on the glacier. Different amounts of ash were deposited on snow or ice, after which the snow properties and melt were measured. The results show that a thin ash layer increases the snow and ice melt but an ash layer exceeding a certain critical thickness caused insulation. Ash with 1 phi in grain size insulated the ice below at a thickness of 9-15 mm. For the 3.5 phi grain size, the insulation thickness is 13 mm. The maximum melt occurred at a thickness of 1 mm for the 1 phi and only 1-2 mm for 3.5 phi ash. A map of dust concentrations on Vatnajokull that represents the dust deposition during the summer of 2013 is presented with concentrations ranging from 0.2 up to 16.6 g m(-2).Peer reviewe

Newly identified climatically and environmentally significant high-latitude dust sources

Dust particles from high latitudes have a potentially large local, regional, and global significance to climate and the environment as short-lived climate forcers, air pollutants, and nutrient sources. Identifying the locations of local dust sources and their emission, transport, and deposition processes is important for understanding the multiple impacts of high-latitude dust (HLD) on the Earth\u27s systems. Here, we identify, describe, and quantify the source intensity (SI) values, which show the potential of soil surfaces for dust emission scaled to values 0 to 1 concerning globally best productive sources, using the Global Sand and Dust Storms Source Base Map (G-SDS-SBM). This includes 64 HLD sources in our collection for the northern (Alaska, Canada, Denmark, Greenland, Iceland, Svalbard, Sweden, and Russia) and southern (Antarctica and Patagonia) high latitudes. Activity from most of these HLD sources shows seasonal character. It is estimated that high-latitude land areas with higher (SI ≥0.5), very high (SI ≥0.7), and the highest potential (SI ≥0.9) for dust emission cover >1 670 000 km$^{2}$, >560 000 km$^{2}$, and >240 000 km$^{2}$, respectively. In the Arctic HLD region (≥60$^{∘}$ N), land area with SI ≥0.5 is 5.5 % (1 035 059 km$^{2}$), area with SI ≥0.7 is 2.3 % (440 804 km$^{2}$), and area with SI ≥0.9 is 1.1 % (208 701 km$^{2}$). Minimum SI values in the northern HLD region are about 3 orders of magnitude smaller, indicating that the dust sources of this region greatly depend on weather conditions. Our spatial dust source distribution analysis modeling results showed evidence supporting a northern HLD belt, defined as the area north of 50$^{∘}$ N, with a “transitional HLD-source area” extending at latitudes 50–58∘ N in Eurasia and 50–55$^{∘}$ N in Canada and a “cold HLD-source area” including areas north of 60$^{∘}$ N in Eurasia and north of 58$^{∘}$ N in Canada, with currently “no dust source” area between the HLD and low-latitude dust (LLD) dust belt, except for British Columbia. Using the global atmospheric transport model SILAM, we estimated that 1.0 % of the global dust emission originated from the high-latitude regions. About 57 % of the dust deposition in snow- and ice-covered Arctic regions was from HLD sources. In the southern HLD region, soil surface conditions are favorable for dust emission during the whole year. Climate change can cause a decrease in the duration of snow cover, retreat of glaciers, and an increase in drought, heatwave intensity, and frequency, leading to the increasing frequency of topsoil conditions favorable for dust emission, which increases the probability of dust storms. Our study provides a step forward to improve the representation of HLD in models and to monitor, quantify, and assess the environmental and climate significance of HLD