Regional aerosol optical properties and radiative impact of the extreme smoke event in the European Arctic in spring 2006

Abstract

Abstract. In spring 2006 a special meteorological situation occurred in the European Arctic region giving record high levels of air pollution. The synoptic situation resulted in extensive transport of pollution predominantly from agricultural fires in Eastern Europe into the Arctic region and record high air-pollution levels were measured at the Zeppelin observatory at Ny-Ålesund (78 • 54 N, 11 • 53 E) in the period from 25 April to 12 May. In the present study we investigate the optical properties of the aerosols from this extreme event and we estimate the radiative forcing of this episode.We examine the aerosol optical properties from the source region and into the European Arctic and explore the evolution of the episode and the changes in the optical properties. A number of sites in Eastern Europe, Northern Scandinavia and Svalbard are included in the study. The observations show that the maximum AOD was from 2-3 May at all sites and varies from 0.52 to 0.87, and the correspondingÅngstrøm exponent was relatively large. Lidar measurements from Minsk, ALOMAR (Arctic Lidar Observatory for Middle Atmosphere Research at Andenes) and NyAlesund show that the aerosol layer was below 3 km at all sites the height is decreasing from the source region and into the Arctic. For the AERONET sites included (Minsk, Toravere, Hornsund) we have further studied the evolution of the aerosol size. The single scattering albedo at Svalbard is proCorrespondence to: C. Lund Myhre (clm@nilu.no) vided for two sites; Ny-Ålesund and Hornsund. Importantly the calculated single scattering albedo based on the aerosol chemical composition and size distribution from Ny-Ålesund and the AERONET measurements at Hornsund are consistent. We have found strong agreement between the satellite daily MODIS AOD and the ground-based AOD observations. This agreement is crucial for accurate radiative forcing calculations. We calculate a strong negative radiative forcing for the most polluted days employing the analysed ground based data, MODIS AOD and a multi-stream model for radiative transfer of solar radiation. During this specific pollution event the forcing reached values as low as −35 W m −2 in the region. For comparison, the direct forcing of a corresponding aerosol layer with a typical AOD of 0.05 for the season is around −5 W m −2 .

Atmospheric Aerosol Over Ukraine Region: Current Status of Knowledge and Research Efforts

“…In the spring AOD reached maximum earlier in the west part of Ukraine and the same in the summer. The comparison of that type of aerosol variation with results of other authors, studied East European aerosols (Lund Myhre et al, 2007;Pietruczuk and Chaikovsky, 2012;Sayer et al, 2012), shows good agreement in seasonal variations. The investigations make it clear that biomass burning is the main process, which responsible for the spring AOD maximum (Figure 10).…”

Lidar-Radiometer Inversion Code (LIRIC) for the retrieval of vertical aerosol properties from combined lidar/radiometer data: development and distribution in EARLINET

“…Nowadays, lidars and sun-skyscanning radiometers are among the basic tools in comprehensive experiments aimed at studying the transformation and transport of smoke (e.g. Lund Myhre et al, 2007;McKendry et al, 2011;Colarco et al, 2004), dust (e.g. Ansmann et al, 2009;McKendry et al, 2007;Müller et al, 2003;Papayannis et al, 2008), and volcanic ash (e.g.…”

Regional radiative impact of volcanic aerosol from the 2009 eruption of Mt. Redoubt

“…15c and 15d, respectively. The LW forcing for smoke is very small because of small particle sizes (Myhre et al, 2007) (Quinn et al, 2007), dust (Stone et al, 2007), smoke (Stone et al, 2008), and ash rich and sulfate rich volcanic aerosols (this study). Values of forcing for dust were only available at the surface.…”

“…Volcanic aerosols may be expected to have a particularly strong influence on the regional Arctic climate because of the high sensitivity of the Arctic environment to radiative perturbations, as indicated by numerous studies focusing on other aerosol types, both natural (Myhre et al, 2007;Stone et al, 2007Stone et al, , 2008 and anthropogenic (Ritter et al, 2005;Quinn et al, 2007Quinn et al, , 2008. The resulting forcing aerosols will have on the Arctic environment is strongly controlled by the seasonality of many related factors, such as the amount of incoming solar radiation, surface albedo, precipitation, and transport of pollutants (Quinn et al, 2008;Sokolik et al, 2011).…”