Notes from the Field

The MOSAiC Floe

March 16th, 2020 by Steven Fons, NASA GSFC

The Central Observatory of MOSAiC, with a few prominent landmarks noted. This photo was taken while the Kapitan Dranitsyn was stationed nearby. Credit: Steven Fons

Floe | flō | n. A sheet of floating ice.

Central to the entire MOSAiC Expedition is the MOSAiC Floe: a large sheet of sea ice that was carefully selected back in October as the ideal place to anchor Polarstern for an entire year. It was chosen due to its size, structure (a mix of thick multiyear sea ice and thinner first year sea ice), and forecasted drift trajectory. Over the past five months, it has become a second home for many scientists. Here’s a brief tour of our workplace:

The Central Observatory (CO):
Nearest to Polarstern, the CO is the primary place where measurements are taken, both from continuously operating instruments and from sampling trips off of Polarstern. It houses many installations, from small stakes just a few inches tall, to larger huts and tents that can comfortably fit a few people inside, to 25-meter-tall towers with dozens of instruments installed. Most installations are grouped into ‘cities’ by scientific discipline. There is MET (meteorology) City, Ocean City, Balloon Town (for weather balloons – not clowns), the Remote Sensing Site, and the ROV (Remote Operated Vehicle) Site, to name a few. There are also clean areas dedicated to the sampling of snow, measuring ice strength, and studying biogeochemical processes. 

Throughout the CO, there are carefully placed roads that lead from Polarstern through the Logistics area (where snowmobiles and other gear are parked) and to the different cities. Perhaps most importantly, there is also a ‘trip wire’ alarm around the CO that is able to send up a signal flare if a polar bear walks into it, providing an additional safety measure when out on the ice.

A map of the MOSAiC Floe, focused on the Central Observatory. Credit: AWI

Area II:
Outside of the CO is known as Area II. This mainly houses the “Dark Site” – a place where sea ice cores are taken each week. The Dark Site consists of two different locations from which cores are drilled: a first year ice site and a second year ice site. This area is located far from the lights of Polarstern and kept as dark as possible, so as not to disturb some of the ecological work that is going on. During the winter darkness, anyone visiting the Dark Site had to use a red headlamp, which has been proven to have the least impact on the organisms living below the ice. Due to the distance away from the CO and Polarstern, visiting Area II requires additional preparation and safety gear. My main task on MOSAiC is drilling sea ice cores, so I will venture to Area II at least once per week during leg 3.

The Distributed Network (DN):
Furthest from Polarstern is the Distributed Network, which is home to exclusively autonomous instrumentation. The DN sites are not part of the MOSAiC Floe, but instead range from around 5 kilometers to over 30 kilometers away from Polarstern. Almost all sites require a helicopter to visit, an usually these visits consist of fixing broken instruments or changing batteries. The purpose of the DN is to have measurements far from Polarstern, in order to determine the representativeness of the MOSAiC floe with respect to the ice in the rest of the Central Arctic. 

Together, these areas make up the field sites of MOSAiC. It’s a pretty cool place to work!

One Response to “The MOSAiC Floe”

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