Arctic Summer Cloud Ocean Study (ASCOS) (ACP/AMT/OS inter-journal SI)(ACP/AMT/OS inter-journal SI)
Arctic Summer Cloud Ocean Study (ASCOS) (ACP/AMT/OS inter-journal SI)(ACP/AMT/OS inter-journal SI)
Editor(s): J. W. Bottenheim, W. M. Drennan, M. Tjernström, C. Leck, I. Brooks, G. de Leeuw, E. Swietlicki and A. Hansel Special issue jointly organized between Atmospheric Chemistry and Physics, Atmospheric Measurement Techniques, and Ocean Science
Clouds constitute one of the major uncertainties in understanding the climate system and changes in the clouds as a consequence of global climate change is not well constrained by observations. This is particularly true in the Arctic, where clouds constitute the larges single factor affecting the surface energy balance, and therefore on melting and freezing of sea ice.

ASCOS is a highly interdisciplinary project with a major field experiment in the central Arctic Ocean during August/September 2008, approximately at 87N and 7W, deployed on the Swedish icebreaker Oden as a part of the International Polar Year (IPY). The ASCOS main target is to study the formation and life cycle of Arctic summer low-level clouds. To achieve this we deployed instruments for process level observations in a column from 0.5 km in to the ocean, through the ocean/ice surface up through the atmospheric boundary layer, and to the top of the troposphere (also see ASCOS measurements range from in-situ observations, to surface-based remote sensing, to airborne observations. The most intense observations were during a 3-week ice drift, starting with typical Arctic summer melt conditions and ending with the initial freeze-up of autumn. ASCOS was also coordinated with the Arctic Mechanisms of Interaction between the Surface and Atmosphere (AMISA) project, providing airborne measurements from the NASA DC8 research aircraft in the vicinity of the ASCOS column, flying in from Kiruna, Sweden.

The science team on Oden consisted of 33 researchers from 14 institutes in 11 different countries; many more are involved in analysis and associated modelling studies. This, and the experimental set-up, makes ASCOS the most extensive atmosphere-oriented experiment in the central Arctic for the entire IPY. ASCOS science cuts across several disciplines, with links to microbial life in ocean and ice, atmospheric chemistry and physics, cloud microphysics, turbulent exchange at the surfaces above and below the ice, and atmospheric circulation. A large part of ASCOS (atmospheric gas and particulate chemistry, aerosol physics, boundary-layer and synoptic meteorology) fall within the remit of ACP while physical oceanography and marine biology/chemistry fall within the remit of OS which is the incentive for a joint ACP/OS issue; only this way will it become possible to develop a special issue spanning the whole width of the science in ASCOS.

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19 Mar 2014
| Overview paper
The Arctic Summer Cloud Ocean Study (ASCOS): overview and experimental design
M. Tjernström, C. Leck, C. E. Birch, J. W. Bottenheim, B. J. Brooks, I. M. Brooks, L. Bäcklin, R. Y.-W. Chang, G. de Leeuw, L. Di Liberto, S. de la Rosa, E. Granath, M. Graus, A. Hansel, J. Heintzenberg, A. Held, A. Hind, P. Johnston, J. Knulst, M. Martin, P. A. Matrai, T. Mauritsen, M. Müller, S. J. Norris, M. V. Orellana, D. A. Orsini, J. Paatero, P. O. G. Persson, Q. Gao, C. Rauschenberg, Z. Ristovski, J. Sedlar, M. D. Shupe, B. Sierau, A. Sirevaag, S. Sjogren, O. Stetzer, E. Swietlicki, M. Szczodrak, P. Vaattovaara, N. Wahlberg, M. Westberg, and C. R. Wheeler
Atmos. Chem. Phys., 14, 2823–2869,,, 2014
31 May 2016
Size-resolved morphological properties of the high Arctic summer aerosol during ASCOS-2008
Evelyne Hamacher-Barth, Caroline Leck, and Kjell Jansson
Atmos. Chem. Phys., 16, 6577–6593,,, 2016
Short summary
15 Jun 2015
Potential source regions and processes of aerosol in the summer Arctic
J. Heintzenberg, C. Leck, and P. Tunved
Atmos. Chem. Phys., 15, 6487–6502,,, 2015
Short summary
06 Mar 2015
Importance of aerosol composition and mixing state for cloud droplet activation over the Arctic pack ice in summer
C. Leck and E. Svensson
Atmos. Chem. Phys., 15, 2545–2568,,, 2015
Short summary
28 Nov 2014
The thermodynamic structure of summer Arctic stratocumulus and the dynamic coupling to the surface
G. Sotiropoulou, J. Sedlar, M. Tjernström, M. D. Shupe, I. M. Brooks, and P. O. G. Persson
Atmos. Chem. Phys., 14, 12573–12592,,, 2014
Short summary
29 Jul 2014
The complex response of Arctic aerosol to sea-ice retreat
J. Browse, K. S. Carslaw, G. W. Mann, C. E. Birch, S. R. Arnold, and C. Leck
Atmos. Chem. Phys., 14, 7543–7557,,, 2014
18 Jul 2014
Single-particle characterization of the high-Arctic summertime aerosol
B. Sierau, R. Y.-W. Chang, C. Leck, J. Paatero, and U. Lohmann
Atmos. Chem. Phys., 14, 7409–7430,,, 2014
07 Apr 2014
Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus
J. Sedlar and M. D. Shupe
Atmos. Chem. Phys., 14, 3461–3478,,, 2014
14 Mar 2014
The Arctic summer atmosphere: an evaluation of reanalyses using ASCOS data
C. Wesslén, M. Tjernström, D. H. Bromwich, G. de Boer, A. M. L. Ekman, L.-S. Bai, and S.-H. Wang
Atmos. Chem. Phys., 14, 2605–2624,,, 2014
13 Jan 2014
Near-surface meteorology during the Arctic Summer Cloud Ocean Study (ASCOS): evaluation of reanalyses and global climate models
G. de Boer, M. D. Shupe, P. M. Caldwell, S. E. Bauer, O. Persson, J. S. Boyle, M. Kelley, S. A. Klein, and M. Tjernström
Atmos. Chem. Phys., 14, 427–445,,, 2014
23 Dec 2013
Size-resolved atmospheric particulate polysaccharides in the high summer Arctic
C. Leck, Q. Gao, F. Mashayekhy Rad, and U. Nilsson
Atmos. Chem. Phys., 13, 12573–12588,,, 2013
19 Dec 2013
Vertical profiling of aerosol particles and trace gases over the central Arctic Ocean during summer
P. Kupiszewski, C. Leck, M. Tjernström, S. Sjogren, J. Sedlar, M. Graus, M. Müller, B. Brooks, E. Swietlicki, S. Norris, and A. Hansel
Atmos. Chem. Phys., 13, 12405–12431,,, 2013
12 Dec 2013
Climate and air quality trade-offs in altering ship fuel sulfur content
A. I. Partanen, A. Laakso, A. Schmidt, H. Kokkola, T. Kuokkanen, J.-P. Pietikäinen, V.-M. Kerminen, K. E. J. Lehtinen, L. Laakso, and H. Korhonen
Atmos. Chem. Phys., 13, 12059–12071,,, 2013
10 Dec 2013
A method for sizing submicrometer particles in air collected on Formvar films and imaged by scanning electron microscope
E. Hamacher-Barth, K. Jansson, and C. Leck
Atmos. Meas. Tech., 6, 3459–3475,,, 2013
24 Sep 2013
Cloud and boundary layer interactions over the Arctic sea ice in late summer
M. D. Shupe, P. O. G. Persson, I. M. Brooks, M. Tjernström, J. Sedlar, T. Mauritsen, S. Sjogren, and C. Leck
Atmos. Chem. Phys., 13, 9379–9399,,, 2013
01 Aug 2012
Meteorological conditions in the central Arctic summer during the Arctic Summer Cloud Ocean Study (ASCOS)
M. Tjernström, C. E. Birch, I. M. Brooks, M. D. Shupe, P. O. G. Persson, J. Sedlar, T. Mauritsen, C. Leck, J. Paatero, M. Szczodrak, and C. R. Wheeler
Atmos. Chem. Phys., 12, 6863–6889,,, 2012
05 Jul 2012
On the chemical dynamics of extracellular polysaccharides in the high Arctic surface microlayer
Q. Gao, C. Leck, C. Rauschenberg, and P. A. Matrai
Ocean Sci., 8, 401–418,,, 2012
18 Jun 2012
Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar
M. D. Shupe, I. M. Brooks, and G. Canut
Atmos. Meas. Tech., 5, 1375–1385,,, 2012
04 May 2012
The summer aerosol in the central Arctic 1991–2008: did it change or not?
J. Heintzenberg and C. Leck
Atmos. Chem. Phys., 12, 3969–3983,,, 2012
11 Apr 2012
Modelling atmospheric structure, cloud and their response to CCN in the central Arctic: ASCOS case studies
C. E. Birch, I. M. Brooks, M. Tjernström, M. D. Shupe, T. Mauritsen, J. Sedlar, A. P. Lock, P. Earnshaw, P. O. G. Persson, S. F. Milton, and C. Leck
Atmos. Chem. Phys., 12, 3419–3435,,, 2012
16 Nov 2011
Cloud condensation nuclei closure study on summer arctic aerosol
M. Martin, R. Y.-W. Chang, B. Sierau, S. Sjogren, E. Swietlicki, J. P. D. Abbatt, C. Leck, and U. Lohmann
Atmos. Chem. Phys., 11, 11335–11350,,, 2011
27 Oct 2011
Aerosol composition and sources in the central Arctic Ocean during ASCOS
R. Y.-W. Chang, C. Leck, M. Graus, M. Müller, J. Paatero, J. F. Burkhart, A. Stohl, L. H. Orr, K. Hayden, S.-M. Li, A. Hansel, M. Tjernström, W. R. Leaitch, and J. P. D. Abbatt
Atmos. Chem. Phys., 11, 10619–10636,,, 2011
18 Aug 2011
Near-surface profiles of aerosol number concentration and temperature over the Arctic Ocean
A. Held, D. A. Orsini, P. Vaattovaara, M. Tjernström, and C. Leck
Atmos. Meas. Tech., 4, 1603–1616,,, 2011
18 May 2011
Mixing, heat fluxes and heat content evolution of the Arctic Ocean mixed layer
A. Sirevaag, S. de la Rosa, I. Fer, M. Nicolaus, M. Tjernström, and M. G. McPhee
Ocean Sci., 7, 335–349,,, 2011
01 Apr 2011
On the potential contribution of open lead particle emissions to the central Arctic aerosol concentration
A. Held, I. M. Brooks, C. Leck, and M. Tjernström
Atmos. Chem. Phys., 11, 3093–3105,,, 2011
14 Feb 2011
Measurements of bubble size spectra within leads in the Arctic summer pack ice
S. J. Norris, I. M. Brooks, G. de Leeuw, A. Sirevaag, C. Leck, B. J. Brooks, C. E. Birch, and M. Tjernström
Ocean Sci., 7, 129–139,,, 2011
10 Jan 2011
An Arctic CCN-limited cloud-aerosol regime
T. Mauritsen, J. Sedlar, M. Tjernström, C. Leck, M. Martin, M. Shupe, S. Sjogren, B. Sierau, P. O. G. Persson, I. M. Brooks, and E. Swietlicki
Atmos. Chem. Phys., 11, 165–173,,, 2011
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