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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

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

Acta Geophysica

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2016

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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.

2

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

Szkop A., Pietruczuk A., Posyniak M.

Acta Geophysica

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2016

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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.

3

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

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

Acta Geophysica

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2014

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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.

4

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

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

Acta Geophysica

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2012

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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.

5

Multiwavelength micropulse lidar for atmospheric aerosol investigation

Posyniak M., Stacewicz T., Miernecki M., Jagodnicka A. K., Malinowski S. P.

Optica Applicata

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2010

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Vol. 40, nr 3

623--632

EN

Multiwavelength micropulse lidar (MML) designed for continuous atmospheric sounding is presented. In its optical emitter, a diode pumped pulsed Nd:YAG laser is used. The laser generates three wavelengths: 1064, 532 and 355 nm. Energies of light pulses are about 30, 15 and 7 J, respectively, while their repetition rate is 2 kHz. Returning light is collected by a Cassegrain telescope with the mirror of 170 mm in diameter. Then, the signal is spectrally separated by a polichromator built with dielectric interference and colour filters. Detection of the signals is performed with three photomultipliers and a multiscaling photon counter. Preliminary results of investigation of aerosol properties during COAST 2009 experiment on the Baltic Sea are presented.

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Measurement of aerosol optical thickness over the Atlantic Ocean and in West Antarctica, 2006-2007

Posyniak M., Markowicz K.

Acta Geophysica

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2009

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Vol. 57, no. 2

494-508

EN

In this paper, optical measurements of aerosol properties made during a ship cruise from Poland to Antarctic Station in September and October 2006, and during the cruise back to Gdynia in April and May 2007 are described. A large gradient of pollution between the clear South Atlantic and the dusty North Atlantic was observed. The maximum of aerosol optical thickness at a wavelength of 500 nm reached 0.4 at 20°N in September 2006 and 0.3 at 40°N in May 2007, respectively. Strong Saharan dust transport is suggested as an explanation for the small values of Ångström exponent observed (values of 0.2 and 0.4 on these respective dates). On the Southern Hemisphere the aerosol optical thickness at 500 nm ranged from 0.05 to 0.2. Significant increases of the aerosol optical thickness were associated with strong wind and sea salt production. Good agreement was found when the in situ measurements of aerosol optical thickness were compared to satellite retrievals and modelling results.