Wyniki wyszukiwania - Biblioteka Nauki

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Classification of Aerosol over Central Europe by Cluster Analysis of Aerosol Columnar Optical Properties and Backward Trajectory Statistics

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Szkop A. , Pietruczuk A. , Posyniak M.

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2016

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tom Vol. 64, no. 6

2650--2676

EN

A cluster analysis is applied to the Aerosol Robotic Network (AERONET) data obtained at Belsk, Poland, as well as three nearby Central European stations (Leipzig, Minsk and Moldova) for estimation of atmospheric aerosol types. Absorption Ångstrom exponent (AAE), aerosol optical thickness (AOT) and extinction Ångstrom exponent (EAE) parameters are used. Clustering in both 2D (AOT, EAE) and 3D (AOT, EAE, AAE) is investigated. A method of air mass backward trajectory analysis is then proposed, with the receptor site at Belsk, to determine possible source regions for each cluster. Four dominant aerosol source regions are identified. The biomass burning aerosol source is localized in the vicinity of Belarusian-Ukrainian border. Slovakia and northern Hungary are found to be the source of urban/industrial pollutants. Western Poland and eastern Germany are the main sources of polluted continental aerosols. The most differentiated source region of Scandinavia, Baltic Sea and Northern Atlantic, associated with lowest values of AOT, corresponds to clean continental and possibly maritime type aerosols.

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The Long-Term (1964-2014) Variability of Aerosol Optical Thickness and its Impact on Solar Irradiance Based on the Data Taken at Belsk, Poland

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Posyniak M. , Szkop A. , Pietruczuk A. , Podgórski J. , Krzyścin J.

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2016

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tom Vol. 64, no. 5

1858--1874

EN

Measurements of the Linke turbidity factor (LTF) were performed at Belsk (20.78°E, 51.83°N), Poland, since 1964. This data is used to retrieve broadband aerosol optical thickness normalized to the air mass equal to 2 (BAOT2). A linear analysis of the BAOT2 changes reveals an upward trend of 0.023±0.017(2σ) in the 1964-1975 period, a downward trend of –0.051±0.017(2σ) in the 1976-1991 period, and afterwards a statistically insignificant trend of –0.009 ± 0.014(2σ). Such pattern may be related to the economic changes in Poland (changing emissions and environmental policies). The elevated BAOT2 values, excluded from the trend, are found in 1984 and 1992 due to the volcanic eruptions of El Chichon and Mt. Pinatubo, respectively. Past AOT values at 340 and 500 nm are reconstructed using a linear relationship found between AOT and BAOT2. The reconstructed data is used by the radiative transfer models to estimate a response of the total solar and erythemal radiation to the changes in the atmospheric aerosols at Belsk.

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Lidar observations of volcanic dust over Polish Polar Station at Hornsund after eruptions of Eyjafjallajokull and Grimsvotn

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Karasiński G. , Posyniak M. , Bloch M. , Sobolewski P. , Małarzewski Ł. , Soroka J.

Acta Geophysica

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2014

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tom Vol. 62, no. 2

316--339

EN

Two significant volcanic eruptions, i.e., Eyjafjallajökull (April-May 2010) and Grímsvötn (May 2011) took place recently in Iceland. Within a few days after eruptions, layers of high aerosol concentration have been observed by multiwavelength lidar of the Polish Polar Station at Hornsund, Svalbard. Measurements of the aerosol’s optical properties indicated a possible presence of volcanic ash transported over the Station. The latter presumption was confirmed by the computed backward trajectories of air masses, showing their paths passing over the location of volcanoes.

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Study of vertical structure of aerosol optical properties with sun photometers and ceilometer during the MACRON campaign in 2007

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Markowicz K. , Zieliński T. , Blindheim S. , Gausa M. , Jagodnicka A. , Kardas A. , Kumala W. , Malinowski S. , Petelski T. , Posyniak M.

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2012

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tom Vol. 60, no. 5

1308-1337

EN

This paper presents the measurements of a vertical structure of aerosol optical properties performed during the MACRON (Maritime Aerosol, Clouds and Radiation Observation in Norway) campaign, which took place in July and August 2007 at ALOMAR observatory on And?ya island (69.279 °N, 16.009 °E, elevation 380 m a.s.l.). The mean value of the aerosol optical thickness (AOT) at 500 nm during campaign was 0.12. Significant increase of the AOT above longtime mean value was observed on 7 and 8 August 2007 when the AOT exceeded 0.4 at 500 nm. Analyses of back trajectories show the aerosol transported from over Africa and Central Europe. The aerosol extinction coefficient obtained from the synergy of ceilometer and sun photometer observations reached 0.05-0.08 km-1 (at 1064 nm) in the dust layer. The single scattering albedo at the ALOMAR observatory decreased during the dust episode to 0.93-0.94, which indicates some absorptive aerosols in the lower PBL.