The Drift of Sea Ice
Anja Sommerfeld of the Alfred Wegener Institute, working with a balloon for experiments during Mosaic training in April.
Sea ice drift and its relationship to altimetry‐derived ocean currents in the Labrador Sea
Credit Credit. By Henry Fountain. Photographs by Esther Horvath. TROMSO, Norway — Just days before the German icebreaker Polarstern sets sail on the largest and most ambitious climate-change research expedition the Arctic has ever seen, an air of quiet pandemonium prevails aboard ship. The crew is performing its own last-minute tasks, including lifting four gleaming new snowmobiles aboard with a crane.
Dangling high in the air, the machines look like insects against the hulking foot-long ship. To the untrained eye, it seems impossible that the chaos will end in a matter of hours.
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On Friday evening the ship was indeed ready to go, and a crowd of several hundred gathered on the dock to see it off. Half an hour later, the Polarstern slipped its moorings and eased out of the harbor, headed north. Joined by a Russian icebreaker carrying more equipment, it will sail east for two weeks to the Laptev Sea, north of Central Siberia.
There the Polarstern will churn through the pack ice and sidle up to an ice floe — a large expanse of intact ice, chosen on the spot after analysis of satellite radar images and other information — and cut its engine, allowing itself to be fully frozen in place. The Russian ship will transfer its equipment to the floe and turn around. Deliberately trapped, if all goes well the Polarstern will travel with the ice along a wind-driven route known as the trans-polar drift toward and past the pole and eventually south, spilling out into the Fram Strait between Greenland and the Svalbard archipelago 12 to 14 months later.
Rex, a researcher in atmospheric physics at the Alfred Wegener Institute in Germany. Organized by the institute, the expedition involves scientists from 19 nations, including the United States, and has been five years in planning. Specialists in Arctic science — more than 60 at any time plus about 40 crew — will operate instruments on board and on the ice, with some autonomous equipment set up about 30 miles away.
The studies — of the atmosphere, ocean, ice and snow, and the interactions among them — are all focused on one goal: a better understanding of how warming will affect the region, now and into the future. While the entire world is heating up, largely because of human activities that release greenhouse gases into the atmosphere, the Arctic is warming about twice as fast as other regions, and the effects are more noticeable there than anywhere else.
Among other impacts, the sea ice itself is changing, becoming less extensive and thinner as the Arctic warms. This year, with the summer melt season coming to an end, ice coverage is near the record low that was set in , according to the National Snow and Ice Data Center in Colorado. Specifically, it is unclear whether forecast systems that account for initial conditions and provide forecasts of the evolving atmosphere, ice, and ocean system, can provide additional skill over drift forecasts made using historical sea-ice velocity fields.
The MOSAiC drift provides a template for assessing the capabilities to forecast sea-ice drift for a range of applications, ranging from logistics support for future field experiments to potential search and rescue operations. The examination of sea-ice drift forecasts provides an integrated assessment of many aspects of the coupled atmosphere-ice-ocean system and will motivate in depth investigations into how key variables are measured, modelled, and forecast.
In particular, we expect coordinated drift forecasts to draw attention to the interaction between sea-ice physics and boundary layer physics in both atmosphere and ocean. We expect that a systematic assessment of real drift forecasting capabilities will improve our physical understanding of sea-ice and enable us to identify and resolve model shortcomings and identify limits of predictability. The slides are available here.
The SIDFEx R-package available here has steadily evolved over the past months and now comes with a user guide that facilitates installing and working with the package. We hope that the package and the user guide prove to be helpful and enable others to join into the analysis of SIDFEx data.
Corresponding calls for July and August will follow in one and two months. As of November , a list of all SIDFEx targets, their valid date ranges and latest positions in simple text format is available here. The list is automatically updated hourly and can be used by contributors to automate the target handling. The Python-based scripts for diagnostic tracking of ice particles have received a minor update on 24 October ; see below. Whereas in the past, sea ice from the shelf seas transported this mineral load to the Fram Strait, today the melting floes release it on their way to the Central Arctic; what reaches the Fram Strait is less material, and with a different composition.
This finding is a result e.
The Transpolar Drift is faltering: Sea ice is now melting before it can leave the nursery
In the long term, this altered sea-ice-based particle transport is likely to produce lasting changes in the biogeochemical cycles and ecological processes of the central Arctic Ocean. The evolution of sea ice and the ecological processes in the Arctic Ocean are also key research questions that will be addressed during the MOSAiC expedition, which will begin this September.
The German research icebreaker Polarstern will journey to the Arctic and drift with the Transpolar Drift through the Arctic Ocean for an entire year, intentionally trapped in the ice. Note: Content may be edited for style and length.
The Drift | News and Tips for NSIDC Data Users
Science News. Journal Reference : Thomas Krumpen, H. Arctic warming interrupts the Transpolar Drift and affects long-range transport of sea ice and ice-rafted matter. Scientific Reports , ; 9 1 DOI: ScienceDaily, 2 April The Transpolar Drift is faltering: Sea ice is now melting before it can leave the nursery. Retrieved September 24, from www.