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 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).
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.
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.
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
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).
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: