What are the consequences of the dramatic loss of summer sea-ice for Arctic climate? Will the ice continue to disappear at an ever-increasing rate as the exposed ocean surface absorbs increasing amounts of solar radiation? Or might conditions become progressively more favorable for biological activity and associated cloud-formation, decreasing the amount of solar-radiation received at the surface? How might the Arctic climate change on inter-annual and inter-decadal time scales and quite how sensitive is it to anthropogenic climate change? These are key questions that the Microbiology-Ocean-Cloud-Coupling in the High Arctic (MOCCHA 2018 campaign) project will strive to answer.

To do so, we will conduct unique measurements during a planned research cruise to the high Arctic in summer 2018 aboard the Swedish icebreaker (I/B) Oden as part of the Arctic Ocean 2018 expedition. During the cruise, which will take place throughout the most active period biologically and into the autumn freeze-up (mid July to September), I/B Oden will drift passively whilst moored to an ice floe. This approach will allow us to utilize a number of innovative techniques and novel measurement approaches and the project will involve contributions from across many fields in the natural sciences.

Projects at ACES

Within ACES, we are responsible for the following projects during the expedition:

  • Quantifying the source of aerosols from open leads in the High Arctic (PI: Matthew Salter)
  • Aerosol-cloud interactions in the High Arctic (PI: Paul Zieger with contributions from Julia Schmale, Paul Scherrer Institute, see link here)
  • Cloud-water and aerosol sampling using a tethered balloon (PI: Paul Zieger and Matthew Salter)

The team from PSI and ACES on top of the triplet container and the Swiss container just before departure (31st of July 2018) in Longyearbyen, Svalbard. Patrick Duplessis is missing on the photo. Photo: Matthias Gottschalk.


The ACES-Team on board Oden will be Linn Karlsson, Julika Zinke, Matt Salter and Paul Zieger. Start will be July, 31st, 2018 (Longyearbyen, Svalbard) and end on September 25th, 2018 (Tromsö, Norway).

The team from ACES: Paul Zieger, Julika Zinke, Linn Karlsson, and Matt Salter (“The A-Team”) shortly before departure (6.7.2018). More than 1.8 tonnes of equipment have to be shipped to I/B Oden.

Aerosol-cloud interactions in the High Arctic

Aerosol and cloud sampling will be performed on the 4th deck using a newly designed whole-air inlet and a special cloud inlet (called the counterflow virtual impactor inlet / CVI), which just samples cloud droplets. Ambient particles and cloud droplets are then dried and characterized using various in-situ instruments. We will use instrumentation to determine the size and chemical composition of the particles. One focus will be the contribution of biogenic particles for which we will use a newly developed bioaerosol sensor. A schematic overview is depicted in the figure below.

On board I/B Oden, cloud and ice nuclei will be sampled using a cloud virtual impactor inlet (CVI) and a whole- air inlet to which a comprehensive suite of aerosol in-situ instrumentation will be connected (part A). Own instrumental contributions are shown in orange while grey boxes are contributions from collaborators. In addition, we will use a tethered balloon to measure aerosol size distribution and alternating with cloud water sampling inside the cloud for chemical analysis (part B).

Julia Schmale and Andrea Baccarini (Paul Scherrer Institute, PSI, Switzerland) will contribute by characterizing the role of new particle formation in the high Arctic and by performing high-resolution chemical analysis of cloud condensation nuclei. Their instrumentation will be located in the red Swiss container next to the triplet container on the 4th deck.

Set-up of measurement containers on the 4th deck. The instrumentation from ACES will be located on and inside the triplet container (aerosol lab).

The counterflow virtual impactor inlet (left) and the new whole-air inlet (right) installed on board I/B Oden during during the mobilization week in July 2018.


Sampling of cloud-water and aerosols using a tethered balloon

We have developed a new instrument to sample the cloud droplets and ice crystals of elevated clouds in the high Arctic. The samples (or the cloud water) will later be analyzed in the laboratory with respect to the chemical composition and the ability to form ice nuclei. The mini-CWS (miniaturized cloud water sampler) will be deployed on a tethered balloon during the expedition. The instrument has been successfully tested together with our collaborators from the University of Leeds (Ian Brooks, Grace Porter and Mike Adams) in May 2018 at Cardington, U.K. (see video above).

Sampling at the open leads

Left: Schematic of the project “Quantifying the source of aerosols from open leads in the High Arctic“. A floating chamber will be used to sample particles which are produced by bubble bursting in the open leads. Right: The first test on Bunsviken (June, 2018) was successful.

One highlight will be the sampling of particles originating from bubble bursting in the open leads. For this purpose, we have designed a floating chamber which is based on the sea spray chamber in our lab at ACES. Particles will characterized concerning their size and chemical composition (filter sampling).

Our collaborators

The projects at Stockholm University are a close collaboration between ACES and MISU. Our national and international partners are from the Paul Scherrer Institute, Switzerland (Julia Schmale, Andrea Baccarini), the University of Leeds, U.K. (Ian Brooks, Ben Murray, Grace Porter, Mike Adams), the University of Leipzig/TROPOS, Germany (Matthias Gotschalk, Manfred Wendisch, Holger Siebert, Silvia Henning), the University of Oldenburg, Germany (Oliver Wurl, Brandy Robinson), University College London, U.K. (Helen Czerski), Dalhousie University, Canada (Patrick Duplessis, Rachel Chang), Environment and Climate Change Canada (Michael Wheeler, Richard Leaitch), Lund University, Sweden (Birgitta Svenningsson, Erik Swietlicki) and University of Michigan, U.S. (Kerri Pratt) and the University of California, Irvine, U.S. (Mike Lawler).

More info and outreach

More information can be found on social media using the hashtag #ArcticOcean2018 (e.g. on Twitter or Instagram) and on the the expedition website on Polarforskningsportalen. Matt will tweet live here. Paul will post on Instagram and for SU (end of September). The press release from Stockholm University can be found here. Helen Czerski is blogging here, while Julia and Andrea will share updates on this site.

A short video about the upcoming Arctic Ocean 2018 expedition prepared by Stockholm University:

Project Info

Project start: 2017

Funded by

The Swedish Polar Research Secretariat, the US National Science Foundation (NSF) and Vetenskapsrådet (VR). We are also grateful to further funding from the Bolin Centre for Climate Research (RA2) and support within the ACAS project funded by the Knut-and-Alice Wallenberg Foundation.