MOSAiC expedition

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Scientists in front of the Polarstern (September 2019)
The Polarstern (autumn 2019)
Polar bears examine the expedition's camp (October 2019)

The MOSAiC expedition ( M ultidisciplinary drifting O bservatory for the S tudy of A rct i c C limate, “Multidisciplinary drift observatory to investigate the Arctic climate”) is a one-year, international expedition to the central Arctic , led by the German Alfred Wegener Institute (AWI).

During the campaign planned for the years 2019 to 2020, the direct vicinity of the North Pole will be reached for the first time with a modern research icebreaker in winter and spring. Measured by the logistical challenges of the company, the total number of participants, the number of participating nations and the available budget of 140 million euros, MOSAiC is the largest research expedition to the Arctic to date. 50 percent of the costs are covered by the budget of the Federal Ministry of Research (BMBF).

The central expedition ship, the research icebreaker Polarstern of the AWI, is supported by supply and support operations of the Russian academy Fedorov and the Kapitan Dranitsyn , the two German research ships Sonne and Maria S. Merian and the Chinese Xue Long 2 . Extensive operations with airplanes and helicopters are also planned. In total, more than 600 people will be active in the central Arctic during the expedition over several phases. The international expedition with more than 80 participating institutions from 20 nations is led by the AWI and is led by the physicist Markus Rex . The goal of MOSAiC, according to its own information, is to examine the complex and currently poorly understood climate processes in the central Arctic, to improve the representation of these processes in global climate models and to contribute to more reliable climate forecasts.

Background and goals

In the winter months, the Arctic sea ice is too thick for research icebreakers to break through. Data from the Central Arctic are therefore almost completely missing, especially in the winter half-year. The model for the MOSAiC expedition to reach the Central Arctic in winter is Fridtjof Nansen's expedition with the wooden research ship Fram from 1893 to 1896 (see Nansen's Fram expedition ). This showed the possibility of allowing a ship, frozen solid in the sea ice of the central Arctic, to drift over the polar dome, propelled solely by the natural movement of the ice in the transpolar drift . While Nansen's drift experiment with the Fram was successful, the scientific measurements of the Fram expedition were rudimentary from today's perspective. For the first time, the MOSAiC expedition goes on the trail of the Fram with a modern research icebreaker , which is equipped with extensive scientific instruments for the investigation of complex climate processes.

Similar drift attempts have already been made in modern science, but on a much smaller scale. In the 1990s, the Royal Canadian Coast Guard's icebreaker Des Groseilliers locked itself in the sea ice and built the SHEBA ( Surface Heat Budget of the Arctic Ocean ) research station. The French sailing schooner Tara was trapped in sea ice in winter 2006/2007 and drifted from the East Siberian Sea into the Fram Strait . In 2015, the Lance of the Norwegian Polar Institute also undertook such a drift expedition.

The backbone of the work of the MOSAiC campaign is the year-round drift of the Polarstern through the central Arctic. The Polarstern broke to September 20, 2019 Norwegian port of Tromso together with the Akademik Fedorov on. It drove east along the Siberian coast, heading north at around 120 ° east and looking for a way into the central Arctic sea ice, which was still possible at this time of the year. At about 85 ° 4,582 'north and 134 ° 25.769' west, the Polarstern's engines were put into idle on October 6th. The ship froze firmly into the sea ice. An extensive research camp was set up on the sea ice next to the ship. The Akademik Fedorov meanwhile deployed a network of observation stations on the ice at a distance of up to 50 km. This network of stations consists of autonomous and remote-controlled instruments that are regularly flown to with the help of helicopters from the central Polarstern . For emergency operations, long-range helicopters will be able to reach Polarstern in phases during the expedition via specially deployed fuel depots on the northernmost Siberian islands .

After a final delivery of fuel, the Akademik Fedorov drove back to Tromsø on October 19. The Polarstern is now drifting with the natural ice drift with the surrounding network of research stations over the North Pole area in order to reach the Fram Strait a year later . In autumn 2020 it will leave the ice again and arrive in Bremerhaven in mid-October. Initially and then again from summer 2020, the ice conditions will allow expedition participants to be supplied and exchanged by the MOSAiC partner icebreakers. The icebreaker Kapitan Dranitsyn reached the Polarstern on December 16, 2019 for an exchange of around 100 employees of the people involved in the expedition, which initiated journey section 2. During the phase from mid-February to mid-June, however, the sea ice does not allow any advance of supply icebreakers.

According to the expedition planning, the German research aircraft Polar 5 and Polar 6 were to land on a runway built next to the ship on the sea ice during the March / April period and supplement the expedition's measurements on a large scale. The aircraft should be refueled on site. Furthermore, the sea ice runway should also be used for the exchange of expedition participants. Since the supply flights were planned via Spitzbergen and this archipelago was cordoned off due to the COVID-19 pandemic and the modest medical facility on site, the flights had to be canceled and postponed. At short notice, the two German research vessels Sonne and Maria S. Merian were finally able to leave Bremerhaven on May 18, 2020 with their crew, provisions and fuel and set course for Svalbard for the next exchange of team and cargo. The Polarstern also interrupted her drift in the sea ice in mid-May 2020 to hit the two research vessels in the Advent fjords near Spitsbergen. During this phase, autonomous measuring devices, deployed and temporarily left behind on the MOSAiC ice floe, continued to document developments on site. On June 17, 2020, the Polarstern was back at the ice floe to continue its drift with the sea ice.

Despite the corona-related cancellation of research flights in April 2020, further research flights are planned for summer 2020.

Political background

The expedition takes place in the context of a society-wide discussion about climate change and climate protection measures. Scientists and donors justify their necessity, among other things, on the fact that they would provide new data for future better political decisions . That is why, according to Federal Science Minister Anja Karliczek, climate researchers are “the heroes of our time”. She pointed out that with more data on the Arctic one could become active in German climate protection: “So it is in our greatest interest to research the Arctic. Only if we know how the climate is developing in the Arctic will we be able to take precautions against climate change in Germany and effectively counteract it. "

Preparation campaign

Experience for the campaign was gained during the longest continuous operation of an ice station under German management in 2017. For two weeks, the research icebreaker Polarstern moored to an ice floe and drifted through the Arctic with it. From this "small drift" scientific and logistical experience for the large one-year ice drift campaign MOSAiC could be gained. Logistic experience with the interplay of the various scientific disciplines atmospheric physics, biogeochemistry, oceanography, environmental physics and organismic biology was gained. The campaign was led by Andreas Macke from the Tropos Leibniz Institute for Tropospheric Research .

Attendees

82 research institutes and state-owned companies from 20 countries from all neighboring continents are involved in the expedition. Scientists from the various institutions work temporarily on the Polarstern ; a number of institutions carry out their own tests and sampling.

The head of MOSAiC is Markus Rex, who leads the expedition himself for a good seven months during sections one, four and five. Christian Haas (section two) and Torsten Kanzow (section three) take over the management on site for around two months each. The captains are Stefan Schwarze (sections one to three) and Thomas Wunderlich (sections four to five) for about six months each .

record

With a distance of 156 kilometers, the Polarstern came closer to the North Pole during the Arctic winter than any ship before.

Research priorities

The main goal of MOSAiC is to develop a better understanding of the coupled climate processes of the central Arctic in order to be able to represent them more precisely in regional and global models. The findings will contribute to improved modeling of the global climate, the weather and the ability to predict arctic sea ice.

The results of the MOSAiC mission will help to improve the understanding of the regional and global consequences of Arctic climate change and sea ice loss and to improve weather and climate forecasts. In doing so, it will support future marine and offshore operations, contribute to a deeper scientific basis for future fisheries and marine traffic along the northern sea route, increase the resilience of coastal residents and drive scientifically sound decisions and political developments.

the atmosphere

The atmosphere measurements during MOSAiC will provide a physical understanding of the local and vertical interactions in the atmosphere . In addition, the characterization of clouds , the atmospheric boundary layer , the surface layer and the surface energy flows will lead to a better understanding of the lower tropospheric processes that interact with the arctic surface. It will be a major challenge to maintain these measurements over the entire annual cycle of the sea ​​ice , especially at the beginning of the freezing period, in order to capture the transition from the open ocean to a very thin layer of sea ​​ice . Measurements at higher altitudes will provide properties of the middle and upper troposphere . In order to expand the understanding of the aerosols over the central Arctic, especially in winter, measurements of the composition of the particles, their physical properties, their direct and indirect radiation effects and their interactions with cloud properties are carried out. Routine radiosonde observations in combination with tethered balloons provide high-resolution profiles of atmospheric temperature and humidity. In addition, the vertical profile of the wind speed and direction is determined by radar measurements in order to record the development of the mesoscale dynamics. The most important thermodynamic parameters as well as the kinematic structures of the atmosphere are examined with the help of microwave and infrared radiometers as well as Raman or Doppler lidar .

Sea ice

The observations extend to physical and mechanical properties, morphology , optical properties and the mass balance of the Arctic sea ​​ice . The focus is on characterizing the properties of snow and ice cover, as well as understanding the processes that determine these properties. Snow pits and ice cores help scientists collect this data. Further aspects of sea ice observation are the determination of the mass budget by measuring the snow depth and the ice thickness, as well as the measurement of the distribution of solar radiation in the ice, the spectral albedo , and the transmission of the ice. In addition, different types of ice are examined over the course of a full annual cycle in order to determine the spatial variability and temporal development of the Arctic ice cover.

ocean

Ocean processes influence the energy balance of the Arctic as well as the growth and melting of the Arctic sea ice through the supply of heat. In addition, they play an important role in the biological activity to bind and potentially export CO 2 . The measurements carried out on water columns will help to understand the following key mechanisms: (1) supply of heat to the interface between sea ice and ocean , (2) absorption of solar radiation and the processing of resulting heat , (3) influences of the deep sea , (4) Productions and exports from the euphotic zone .

Since one of the main goals of the MOSAiC expedition is the understanding of the development of sea ice, near-ice ocean processes, such as near-surface mixing, form the focus of the oceanographic measurements . For this purpose, the dynamics and thermodynamics of the mixed ocean layer are examined in detail. Accordingly, continuous measurements of turbulent flows directly below the ocean-ice interface are being made to understand ice and ocean velocities, vertical heat and momentum flows, mass diffusion, and other key processes. In addition, the deeper ocean is observed in a larger context by taking routine profiles of velocity, temperature, salinity, and dissolved oxygen in the upper hundred meters of the Arctic Ocean to understand its impact on the upper ocean-ice interface.

Ecosystem and biogeochemistry

The observation of biological and biogeochemical transformation and succession focuses on the study of ice, snow and water samples. At the same time, flow measurements are to be carried out on both the ice / water and the ice / air boundary layers. These measurements are carried out over a complete and continuous annual Arctic cycle in order to quantify the biology and biogeochemistry of the Arctic Ocean atmospheric system in every season, especially in the under-explored arctic winter. For example, the annual mass budget of organic and inorganic carbon is monitored, including crystallographic measurements of ikaite in the brine channels. These will relate to the net air / ice flux of CO 2 caused by sea ​​ice biogeochemistry , as well as the potential for organic carbon capture and respiration of CO 2 . In addition, a goal is to quantify methane accumulation, oxidation under the sea ice and air / ocean fluxes for the potential for large oceanic methane fluxes into the atmosphere . A third key element will be the observation of the cycle of biogenic gases such as N 2 O , O 2 , DMS (dimethyl sulfide) or bromoform in snow , sea ice and water , which will contribute to the understanding of the underlying biogeochemical pathways. Another important aspect will be the establishment of an annual mass balance and an ice / water cycle of macro and micronutrients by measuring the vertical nutrient flows between the sea, the euphotic zone , the mixed and the deep layer of the sea in combination with molecular tools to understand the recycling chains.

Modeling

A close link between the model and observation concept played a key role in defining and planning the MOSAiC expedition. In order to understand and explain the changes in the Arctic climate system , models are developed in cooperation with the observations and measurements and existing models are improved. These observations then in turn play an important role in improving these and in developing further models for weather and sea ​​ice forecasting as well as climate projection. Furthermore, models will enable a view of phenomena that cannot be directly observed. The observations of the MOSAiC expedition will provide new boundary conditions for models of many orders of magnitude. For example, high-resolution models are used for detailed studies, which will then serve as the basis for improving regional and global climate models.

In addition, regional Arctic models are used to answer important questions about the Arctic as a global energy sink , how global interconnection patterns are affected by changing Arctic ice volume, and the effects of these changes on circulation and weather at lower latitudes . The MOSAiC modeling and observation activities work closely with the international modeling efforts of the World Weather Research Program and the World Climate Research Program .

Web links

Commons : MOSAIC  - collection of images, videos and audio files

Individual evidence

  1. ↑ Sonja Fröhlich: A year on the ice floe . In: Kölner Stadt-Anzeiger . No. 217/2019 . Cologne September 18, 2019, Topic of the Day, p. 2 .
  2. ↑ "Polarstern" makes the biggest Arctic expedition of all time - "Mosaic" expedition. Retrieved September 21, 2019 .
  3. ↑ a b List of partner institutions on the website of the MOSAiC expedition. Retrieved April 9, 2020.
  4. ↑ Jonathan Amos: Scientists begin 'biggest ever' Arctic expedition. BBC News, September 21, 2019, accessed September 23, 2019 .
  5. ^ Tour of Norwegian Arctic science ship. BBC News, May 5, 2015, accessed September 23, 2019 .
  6. ↑ a b c Kai Strittmatter: "The wild life at the North Pole". In: Tages-Anzeiger -online. Retrieved May 25, 2020 .
  7. ↑ Alternative plan for Polarstern supply is available - AWI. Retrieved May 12, 2020 .
  8. ^ Rendezvous of the research ships . Retrieved July 7, 2020 .
  9. ↑ a b Polarstern back at the MOSAiC ice floe. Alfred Wegener Institute, accessed on July 7, 2020 .
  10. ↑ MOSAiC flight campaigns to measure the atmosphere and sea ice are not taking place for the time being - AWI. Retrieved May 12, 2020 .
  11. ↑ dpa: A year in the pack ice: icebreaker "Polarstern" started. September 20, 2019, accessed on September 29, 2019 (German).
  12. ↑ BMBF Internet editorial office: "We are advancing into regions beyond the imagination" - BMBF. Retrieved September 21, 2019 .
  13. ^ Alfred Wegener Institute: MOSAiC team. In: MOSAiC official website. Alfred Wegener Institute, September 20, 2019, accessed on January 2, 2020 .
  14. ↑ a b Alfred Wegener Institute: Science Plan, MOSAiC Expedition . Ed .: Alfred Wegener Institute. 2016 ( Online [PDF]).
  15. ↑ a b c d e Alfred Wegener Institute: Implementation Plan, MOSAiC Expedition . Ed .: Alfred Wegener Institute. 2018 ( Online [PDF]).
  16. ↑ a b Alfred Wegener Institute: The Expedition - MOSAIC. Alfred Wegener Institute, August 22, 2018, accessed on March 27, 2019 .