Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project

Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Brock C.A.; Cozic J.; Bahreini R.; et al. - Copernicus GmbH, 2011

We present an overview of the background, scientific goals, and execution of the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project of April 2008. We then summarize airborne measurements, made in the troposphere of the Alaskan Arctic, of aerosol particle size distributions, composition, and optical properties and discuss the sources and transport of the aerosols. The aerosol data were grouped into four categories based on gas-phase composition. First, the background troposphere contained a relatively diffuse, sulfate-rich aerosol extending from the top of the sea ...

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Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project

  Available online: http://dx.doi.org/10.5194/acp-11-2423-2011

C.A. Brock ; J. Cozic ; R. Bahreini ; K.D. Froyd ; A.M. Middlebrook ; A. McComiskey ; J. Brioude ; O.R. Cooper ; A. Stohl ; K.C. Aikin ; J.A. de Gouw ; D.W. Fahey ; R.A. Ferrare ; R.-S. Gao ; W. Gore ; J.S. Holloway ; G. Hübler ; A. Jefferson ; D.A. Lack ; S. Lance ; R.H. Moore ; D.M. Murphy ; A. Nenes ; P.C. Novelli ; J.B. Nowak ; J.A. Ogren ; J. Peischl ; R.B. Pierce ; P. Pilewskie ; P.K. Quinn ; T.B. Ryerson ; K.S. Schmidt ; J.P. Schwarz ; H. Sodemann ; J.R. Spackman ; H. Stark ; D.S. Thomson ; T. Thornberry ; P. Veres ; L.A. Watts ; C. Warneke ; A.G. Wollny

in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 3 [03/01/2011] . - p.2423-2453

We present an overview of the background, scientific goals, and execution of the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project of April 2008. We then summarize airborne measurements, made in the troposphere of the Alaskan Arctic, of aerosol particle size distributions, composition, and optical properties and discuss the sources and transport of the aerosols. The aerosol data were grouped into four categories based on gas-phase composition. First, the background troposphere contained a relatively diffuse, sulfate-rich aerosol extending from the top of the sea-ice inversion layer to 7.4 km altitude. Second, a region of depleted (relative to the background) aerosol was present within the surface inversion layer over sea-ice. Third, layers of dense, organic-rich smoke from open biomass fires in southern Russia and southeastern Siberia were frequently encountered at all altitudes from the top of the inversion layer to 7.1 km. Finally, some aerosol layers were dominated by components originating from fossil fuel combustion.
Of these four categories measured during ARCPAC, the diffuse background aerosol was most similar to the average springtime aerosol properties observed at a long-term monitoring site at Barrow, Alaska. The biomass burning (BB) and fossil fuel layers were present above the sea-ice inversion layer and did not reach the sea-ice surface during the course of the ARCPAC measurements. The BB aerosol layers were highly scattering and were moderately hygroscopic. On average, the layers produced a noontime net heating of ~0.1 K day−1 between 3 and 7 km and a slight cooling at the surface. The ratios of particle mass to carbon monoxide (CO) in the BB plumes, which had been transported over distances >5000 km, were comparable to the high end of literature values derived from previous measurements in wildfire smoke. These ratios suggest minimal precipitation scavenging and removal of the BB particles between the time they were emitted and the time they were observed in dense layers above the sea-ice inversion layer.

Language(s): English

Format: Digital (Free)

Tags: Aerosols ; Atmospheric circulation ; Climate ; Impact studies ; Cloud formation ; Research ; Arctic Add tag

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GAW Report, 195. WMO/GAW Expert Workshop on Global Long-term Measurements of Nitrogen Oxides and Recommendations for GAW Nitrogen Oxides Network

World Meteorological Organization (WMO) ; Gilge S.; Plass-Duelmer C.; et al. - WMO, 2011 (WMO/TD-No. 1570)

Nitrogen oxides are a component of a group of reactive gases required to be measured in the GAW Programme. The reactive gases group focuses on gases known to be intimately involved in various aspects of the chemistry of the troposphere and includes surface ozone (O3), carbon monoxide (CO), volatile organic compounds (VOCs), and sulphur dioxide (SO2), as well as oxidized nitrogen species. The sum of nitric oxide (NO) and nitrogen dioxide (NO2) has traditionally been called NOx. The sum of oxidized nitrogen species with an oxidation number >1, both organic and inorganic, is referred to as ...

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 WMO/GAW Expert Workshop on Global Long-term Measurements of Nitrogen Oxides and Recommendations for GAW Nitrogen Oxides Network

  Available online: Full text

World Meteorological Organization (WMO) ; S. Gilge ; C. Plass-Duelmer ; I. Galbally ; N. Brough ; J. Bottenheim ; F. Flocke ; H. Gerwig ; J. Lee ; M. Milton ; F. Rohrer ; T.B. Ryerson ; M. Steinbacher ; K. Torseth ; R. Wielgosz ; Kazuto Suda ; H. Akimoto ; Oksana Tarasova

Event: WMO/GAW Expert Workshop on Global Long-term Measurements of Nitrogen Oxides and Recommendations for GAW Nitrogen Oxides Network (8-9 October 2009; Hohenpeissenberg, Germany)

Published by: WMO ; 2011

Nitrogen oxides are a component of a group of reactive gases required to be measured in the GAW Programme. The reactive gases group focuses on gases known to be intimately involved in various aspects of the chemistry of the troposphere and includes surface ozone (O3), carbon monoxide (CO), volatile organic compounds (VOCs), and sulphur dioxide (SO2), as well as oxidized nitrogen species. The sum of nitric oxide (NO) and nitrogen dioxide (NO2) has traditionally been called NOx. The sum of oxidized nitrogen species with an oxidation number >1, both organic and inorganic, is referred to as NOy (see Table 1 for individual molecules) (Fahey et al.,1985). Nitrous oxide (N2O) is obviously an oxide of nitrogen but it is not dealt with in this report because it is inert in the troposphere. It is measured separately by another component in the GAW Programme because of its role as a greenhouse gas.
The focus of this report is on NO and NO2 mostly because their measurements are presently more extensive and it is thus easier to establish high quality measurements with a fully implemented quality assurance system. Measurements of total NOy are presently undertaken in the GAW framework but the measurement quality control and calibration methodology is deemed not mature enough at present to recommend the inclusion of total NOy measurements for GAW.

Collection(s) and Series: WMO/TD- No. 1570; GAW Report- No. 195

Language(s): English

Format: Digital (Free) (ill., charts, maps)

Tags: Observations ; Reactive Gases ; Nitrous oxide (N2O) ; Measure ; Global Atmosphere Watch Programme (GAW) ; GAW 195 Add tag

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