Abstract
Abstract. As a part of the IPY project POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate Chemistry, Aerosols and Transport), this paper studies the sources of equivalent black carbon (EBC), sulphate, light-scattering aerosols and ozone measured at the Arctic stations Zeppelin, Alert, Barrow and Summit during the years 2000–2007. These species are important pollutants and climate forcing agents, and sulphate and EBC are main components of Arctic haze. To determine where these substances originate, the measurement data were combined with calculations using FLEXPART, a Lagrangian particle dispersion model. The climatology of atmospheric transport from surrounding regions on a twenty-day time scale modelled by FLEXPART shows that the stations Zeppelin, Alert and Barrow are highly sensitive to surface emissions in the Arctic and to emissions in high-latitude Eurasia in winter. Emission sensitivities over southern Asia and southern North America are small throughout the year. The high-altitude station Summit is an order of magnitude less sensitive to surface emissions in the Arctic whereas emissions in the southern parts of the Northern Hemisphere continents are more influential relative to the other stations. Our results show that for EBC and sulphate measured at Zeppelin, Alert and Barrow, northern Eurasia is the dominant source region. For sulphate, Eastern Europe and the metal smelting industry in Norilsk are particularly important. For EBC, boreal forest fires also contribute in summer. No evidence for any substantial contribution to EBC from sources in southern Asia is found. European air masses are associated with low ozone concentrations in winter due to titration by nitric oxides, but are associated with high ozone concentrations in summer due to photochemical ozone formation. There is also a strong influence of ozone depletion events in the Arctic boundary layer on measured ozone concentrations in spring and summer. These results will be useful for developing emission reduction strategies for the Arctic.
Highlights
In the late 19th century, some of the early Arctic explorers noticed “dirty” deposits on the ice and snow in remote areas of the Arctic and speculated on their origin (Nordenskiold, 1883; Nansen, 1961; Garrett and Verzella, 2008)
Nsooutriccees tihnaAt lsaysmkabaonlsd ffor BSuamrrmowit iannd ZefeprpeneclienisarlaergselisgthfrtolymoOffcsteotbeirnutnimtileMfaoyr acnladriisfymost likely sA1p0mr4ine5rgicaansdoefefanpllra.etsBTehanretraoatwpiopmnar.iegnhtt lack of influence from North not be entirely representative the result of a stronger impact of wet scavenging at the Zeppelin station, which is influenced by low pressure systems ff1or0or4mt6hims opsatrtNoofrtthheAAmrcetriiccasninscoeuerpceisoredgeisonwsithhadvieremcot strtalynsbpeoernt arriving from the North Atlantic Ocean
In this paper we have employed a novel method to combine the calculations from a Lagrangian particle dispersion model, FLEXPART, and measurement data from four Arctic stations (Zeppelin, Alert, Barrow and Summit) in a statistical analysis of the source regions of short-lived pollutants
Summary
In the late 19th century, some of the early Arctic explorers noticed “dirty” deposits on the ice and snow in remote areas of the Arctic and speculated on their origin (Nordenskiold, 1883; Nansen, 1961; Garrett and Verzella, 2008). Around the year of 1894, Nansen hypothesized that these deposits must have been transported via the atmosphere from faraway source regions but he did not relate them to air pollution. While it cannot be proven that these old reports of “dirty snow” were caused by air pollution, this is a likely explanation. A historical ice-core record of black carbon (BC) shows that BC concentrations over Greenland peaked around. D. Hirdman et al.: Source identification of short-lived air pollutants in the Arctic
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
