Aerosol characterization at the sub‐Arctic site Andenes (69°N, 16°E), by the analysis of columnar optical properties

Rodríguez, Edith; Toledano, Carlos; Cachorro, Victoria E.; Serrano-Ortiz, Penélope; Stebel, K.; Berjón, A.; Blindheim, S.; Gausa, Michael; Baraja, Angel Máximo de Frutos

doi:10.1002/qj.921

Cited by 23 publications

(24 citation statements)

References 44 publications

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“…3b) matches the median range of 1.46-1.49 obtained from a validation study that compares the AE retrieved by SeaWiFS and MODIS Aqua or Terra with the three AERONET stations over the Baltic Sea (Melin et al, 2013). Comparable high AE values were collected by Rodriguez et al (2012) from 2002 to 2011 at the subarctic ALO-MAR Observatory (Andøya, Norway): the AE peaks during the summer season with a multi-annual mean and standard deviation of 1.3 ± 0.4. The AI (Fig.…”

Section: Resultssupporting

confidence: 76%

Estimates of the aerosol indirect effect over the Baltic Sea region derived from 12 years of MODIS observations

et al. 2017

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Abstract. Retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) on-board the Aqua satellite, 12 years (2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014) of aerosol and cloud properties were used to statistically quantify aerosol-cloud interaction (ACI) over the Baltic Sea region, including the relatively clean Fennoscandia and the more polluted central-eastern Europe. These areas allowed us to study the effects of different aerosol types and concentrations on macro-and microphysical properties of clouds: cloud effective radius (CER), cloud fraction (CF), cloud optical thickness (COT), cloud liquid water path (LWP) and cloud-top height (CTH). Aerosol properties used are aerosol optical depth (AOD), Ångström exponent (AE) and aerosol index (AI). The study was limited to low-level water clouds in the summer.The vertical distributions of the relationships between cloud properties and aerosols show an effect of aerosols on low-level water clouds. CF, COT, LWP and CTH tend to increase with aerosol loading, indicating changes in the cloud structure, while the effective radius of cloud droplets decreases. The ACI is larger at relatively low cloud-top levels, between 900 and 700 hPa. Most of the studied cloud variables were unaffected by the lower-tropospheric stability (LTS), except for the cloud fraction.The spatial distribution of aerosol and cloud parameters and ACI, here defined as the change in CER as a function of aerosol concentration for a fixed LWP, shows positive and statistically significant ACI over the Baltic Sea and Fennoscandia, with the former having the largest values. Small negative ACI values are observed in central-eastern Europe, suggesting that large aerosol concentrations saturate the ACI.

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Section: Resultssupporting

confidence: 76%

Estimates of the aerosol indirect effect over the Baltic Sea region derived from 12 years of MODIS observations

et al. 2017

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“…Whereas columnar aerosol properties are presented in Toledano et al (2006), Rodríguez et al (2011) and Rodríguez et al (2012), no surface measurements appear to have been reported for the in situ properties of aerosols in our study area. The site belongs to the AERONET network, and therefore, the columnar aerosol data are also readily available (Rodríguez et al, 2011) and were used as complementary information.…”

Section: Introductioncontrasting

confidence: 76%

In situ measurements of aerosol optical properties and number size distributions in a coastal region of Norway during the summer of 2008

et al. 2012

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Abstract. In situ measurements of aerosol optical properties and particle size distributions were made in the summer of 2008 at the ALOMAR station facility (69°16' N, 16°00' E), located in a rural site in the north of the island of Andøya (Vesterålen archipelago), approximately 300 km north of the Arctic Circle. The extended three-month campaign was part of the POLARCAT Project (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport) of the International Polar Year (IPY-2007-2008). Our goal was to characterize the aerosols of this sub-Arctic area, which are frequently transported to the Arctic region. Data from 13 June to 26 August 2008 were available and the statistical data for all instruments were calculated based on the hourly averages. The overall data coverage was approximately 72%. The hourly mean values of the light-scattering coefficient, σs, and the light-absorption coefficient, σa, at 550 nm were 5.41 Mm−1 (StD = 3.55 Mm−1) and 0.40 Mm−1 (StD = 0.27 Mm−1), respectively. The scattering/absorption Ångström exponents, αs,a, were used in a detailed analysis of the variations of the spectral shape of σs,a. While αs indicates the presence of two particle sizes corresponding to two types of aerosols, αa indicates only one type of absorbing aerosol particle. αa values greater than 1 were not observed. The single-scattering albedo, ω0, ranged from 0.62 to 0.99 (mean = 0.91, StD = 0.05), and the relationships between this parameter and the absorption/scattering coefficients and the Ångström exponents are presented. Any absorption value may lead to the lowest values of ω0, whereas only the lowest scattering values were observed in the lowest range of ω0. For a given absorption value, lower ω0 were observed for smaller αs. The submicrometer, micrometer and total concentrations of the particles presented hourly mean values of 1277 cm−3 (StD = 1563 cm−3), 1 cm−3 (StD = 1 cm−3) and 2463 cm−3 (StD = 4251 cm−3), respectively, and the modal correlations were also investigated. The optical and microphysical parameters, as well as their relationship with each other, are reported. σs correlated strongly with the number concentration of accumulation mode particles and more strongly with the micrometer fraction of particles, but weak correlations were observed for the Aitken and nucleation modes. The origins and pathways of the air masses were examined, and based on sector classification, a relationship between the air mass origin, the optical parameters and the size distributions was established. The low values of the optical and microphysical parameters indicate that the predominant regional aerosol is mostly clean and the shape of the size distribution is characterized by bimodal median size distributions. However, the relationships between the air mass origins and the parameters studied allow us to describe two characteristic situations: the one of the northern and western air masses, which were predominantly composed of marine aerosols and presented the lowest optical and microphysical values observed, indicating predominantly non-absorbent and coarser particles; and the one of the eastern and southern air masses, in which continental aerosols were predominant and exhibited higher values for all parameters, indicating the presence of smaller absorbent particles. The north-northeastern air masses presented the strongest Aitken mode, indicating more recently formed particles, and the southeastern air masses presented the strongest accumulation mode (however, the southeastern air masses were the least common, accounting for only 3% of occurrences).

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“…through transport across Northern Europe and across the Atlantic Ocean around the Bermuda High (e.g. Rodríguez et al, ; VanCuren et al, ). Moreover, this path may be the most effective one in terms of dust load import into the Arctic given the fact that it is the shortest and most direct path.…”

Section: Discussionmentioning

confidence: 79%

“…Additionally, previous chemical and back‐trajectory analyses point to evidence of transport of Saharan dust to the Arctic either through transport across Northern Europe or across the Atlantic Ocean around the Bermuda High (Ansmann et al, ; Franzén et al, ; Rodríguez et al, ; VanCuren et al, ). Few individual episodes of Saharan transport toward the Arctic have been documented in the last 10 years.…”

Section: Introductionmentioning

confidence: 99%

Polar Jet Associated Circulation Triggered a Saharan Cyclone and Derived the Poleward Transport of the African Dust Generated by the Cyclone

et al. 2018

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In this study, we identify a new mechanism by which dust aerosols travel over long distances across the eastern side of the North Atlantic Ocean toward the Arctic. The meandering polar jet was at the origin of both dust emission through cyclogenesis over Northwest Africa and poleward transport of the uplifted dust toward the Arctic, through cut-off circulation. The dust emission was associated with an intense

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Aerosol characterization at the sub‐Arctic site Andenes (69°N, 16°E), by the analysis of columnar optical properties

Cited by 23 publications

References 44 publications

Estimates of the aerosol indirect effect over the Baltic Sea region derived from 12 years of MODIS observations

Estimates of the aerosol indirect effect over the Baltic Sea region derived from 12 years of MODIS observations

In situ measurements of aerosol optical properties and number size distributions in a coastal region of Norway during the summer of 2008

Polar Jet Associated Circulation Triggered a Saharan Cyclone and Derived the Poleward Transport of the African Dust Generated by the Cyclone

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