Aerosol remote sensing in polar regions
Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness τ(λ) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent α were calcul...
Published in: | Earth-Science Reviews |
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Main Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
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ELSEVIER SCIENCE BV
2015
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Online Access: | https://epic.awi.de/id/eprint/36896/ https://epic.awi.de/id/eprint/36896/1/Tomasi_2014overviewaerosol.pdf https://hdl.handle.net/10013/epic.44661 https://hdl.handle.net/10013/epic.44661.d001 |
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institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness τ(λ) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent α were calculated. Analysing these data, the monthly mean values of τ(0.50 μm) and α and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of α versus τ(0.50 μm) showed: (i) a considerable increase in τ(0.50 μm) for the Arctic aerosol from summer to winter–spring, without marked changes in α; and (ii) a marked increase in τ(0.50 μm) passing from the Antarctic Plateau to coastal sites, whereas α decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of τ(λ) and α at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of τ(λ) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions. |
format |
Article in Journal/Newspaper |
author |
Tomasi, Claudio Kokhanovsky, Alexander A. Lupi, Angelo Ritter, Christoph Smirnov, Alexander O'Neill, Norman T. Stone, Robert S. Holben, Brent N. Nyeki, Stephan |
spellingShingle |
Tomasi, Claudio Kokhanovsky, Alexander A. Lupi, Angelo Ritter, Christoph Smirnov, Alexander O'Neill, Norman T. Stone, Robert S. Holben, Brent N. Nyeki, Stephan Aerosol remote sensing in polar regions |
author_facet |
Tomasi, Claudio Kokhanovsky, Alexander A. Lupi, Angelo Ritter, Christoph Smirnov, Alexander O'Neill, Norman T. Stone, Robert S. Holben, Brent N. Nyeki, Stephan |
author_sort |
Tomasi, Claudio |
title |
Aerosol remote sensing in polar regions |
title_short |
Aerosol remote sensing in polar regions |
title_full |
Aerosol remote sensing in polar regions |
title_fullStr |
Aerosol remote sensing in polar regions |
title_full_unstemmed |
Aerosol remote sensing in polar regions |
title_sort |
aerosol remote sensing in polar regions |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2015 |
url |
https://epic.awi.de/id/eprint/36896/ https://epic.awi.de/id/eprint/36896/1/Tomasi_2014overviewaerosol.pdf https://hdl.handle.net/10013/epic.44661 https://hdl.handle.net/10013/epic.44661.d001 |
geographic |
Antarctic Antarctic Peninsula Arctic Arctic Ocean Austral Indian Ny-Ålesund Pacific The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Arctic Arctic Ocean Austral Indian Ny-Ålesund Pacific The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Arctic Arctic Ocean Ny Ålesund Ny-Ålesund |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Arctic Arctic Ocean Ny Ålesund Ny-Ålesund |
op_source |
EPIC3Earth-Science Reviews, ELSEVIER SCIENCE BV, 140, pp. 108-157, ISSN: 0012-8252 |
op_relation |
https://epic.awi.de/id/eprint/36896/1/Tomasi_2014overviewaerosol.pdf https://hdl.handle.net/10013/epic.44661.d001 Tomasi, C. , Kokhanovsky, A. A. , Lupi, A. , Ritter, C. , Smirnov, A. , O'Neill, N. T. , Stone, R. S. , Holben, B. N. and Nyeki, S. (2015) Aerosol remote sensing in polar regions , Earth-Science Reviews, 140 , pp. 108-157 . doi:10.1016/j.earscirev.2014.11.001 <https://doi.org/10.1016/j.earscirev.2014.11.001> , hdl:10013/epic.44661 |
op_doi |
https://doi.org/10.1016/j.earscirev.2014.11.001 |
container_title |
Earth-Science Reviews |
container_volume |
140 |
container_start_page |
108 |
op_container_end_page |
157 |
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1766134286431289344 |
spelling |
ftawi:oai:epic.awi.de:36896 2023-05-15T13:40:26+02:00 Aerosol remote sensing in polar regions Tomasi, Claudio Kokhanovsky, Alexander A. Lupi, Angelo Ritter, Christoph Smirnov, Alexander O'Neill, Norman T. Stone, Robert S. Holben, Brent N. Nyeki, Stephan 2015-01 application/pdf https://epic.awi.de/id/eprint/36896/ https://epic.awi.de/id/eprint/36896/1/Tomasi_2014overviewaerosol.pdf https://hdl.handle.net/10013/epic.44661 https://hdl.handle.net/10013/epic.44661.d001 unknown ELSEVIER SCIENCE BV https://epic.awi.de/id/eprint/36896/1/Tomasi_2014overviewaerosol.pdf https://hdl.handle.net/10013/epic.44661.d001 Tomasi, C. , Kokhanovsky, A. A. , Lupi, A. , Ritter, C. , Smirnov, A. , O'Neill, N. T. , Stone, R. S. , Holben, B. N. and Nyeki, S. (2015) Aerosol remote sensing in polar regions , Earth-Science Reviews, 140 , pp. 108-157 . doi:10.1016/j.earscirev.2014.11.001 <https://doi.org/10.1016/j.earscirev.2014.11.001> , hdl:10013/epic.44661 EPIC3Earth-Science Reviews, ELSEVIER SCIENCE BV, 140, pp. 108-157, ISSN: 0012-8252 Article isiRev 2015 ftawi https://doi.org/10.1016/j.earscirev.2014.11.001 2021-12-24T15:40:03Z Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness τ(λ) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent α were calculated. Analysing these data, the monthly mean values of τ(0.50 μm) and α and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of α versus τ(0.50 μm) showed: (i) a considerable increase in τ(0.50 μm) for the Arctic aerosol from summer to winter–spring, without marked changes in α; and (ii) a marked increase in τ(0.50 μm) passing from the Antarctic Plateau to coastal sites, whereas α decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of τ(λ) and α at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of τ(λ) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Arctic Arctic Ocean Ny Ålesund Ny-Ålesund Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Antarctic Peninsula Arctic Arctic Ocean Austral Indian Ny-Ålesund Pacific The Antarctic Earth-Science Reviews 140 108 157 |