Melting sea ice: An unsuspected domino effect

15 December 2021
Seven years ago, AWI researchers began constructing a new ocean observatory in Fram Strait, which has gathered data on the physics, chemistry and biology of the ocean round the clock – and in summer and winter alike – ever since. An analysis of the first yearly datasets yielded surprising insights into the role of sea ice for life in polar waters. Depending on where and how quickly the sea ice melts, the species makeup and the growth of plankton in the water column – and therefore the available food in the deep sea – can change. Read more here ...

Recycling Sensor Data

19 November 2021
Although satellite-based observation provides impressive spatial resolution with regard to the ice cover, when it comes to measuring ice thickness, it offers comparatively low chronological resolution (weekly and monthly means) and is prone to certain inaccuracies. As such, further improving the analysis and interpretation of satellite data calls for direct and local ice-thickness measurements, gathered over periods that are as long as possible. Read more here ...

Sea-ice Minimum: Prolonged Low Atmospheric Pressure Slows Ice Retreat in the Arctic

16 September 2021
In September, the summer sea-ice melting ends in the Arctic. In other words, on a certain day of the month, the sea-ice cover reaches its lowest extent for the year and then begins growing again, because the surface water begins freezing again. Polar and climate researchers around the globe watch with great interest to see how much sea ice survives the summer. This year, the summer heat had a more moderate effect on the Arctic than in the past five years. Up to the end of the current melting season on 12 September 2021, the Arctic sea-ice cover shrank to a total area of 4.81 million square kilometres; 1.54 Million square kilometres more than in the record low year 2012. Back then, the satellites recorded a residual area of 3.27 million square kilometres. As such, the 2021 Arctic sea-ice minimum comes in at 12th place on the negative list for absolute valuesch somit auf Platz 12 der Negativliste für die Absolutwerte ein. Read more here...

IceBird Summer 2021 – First Results of Sea-ice Thickness Measurements Taken off Northeast Greenland

15 September 2021
After a two-year break, this year experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) were able to return to Station Nord in northeast Greenland, to resume their annual sea-ice measurements north of Greenland and over Fram Strait. The measuring campaign MELTEX/IceBird 2021 with the aeroplane Polar 6 consisted of two parts, each with its own research focus: the goal of MELTEX (27 July – 10 August 2021) was to determine the spatial extent of meltwater ponds on the ice, and to observe the size distribution and depth of the ponds in relation to the floes’ topography. In turn, the focus of the IceBird summer campaign (14 August – 1 September 2021) was on continuing the long-term ice thickness time series at the southern end of the Transpolar Drift. Read more here…

The MOSAiC drift expedition viewed from space: Analysis of the sea-ice conditions throughout the drift and comparison with previous years

30 August 2021
Roughly two years ago, on 4 October 2019, the research icebreaker Polarstern, operated by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, allowed herself to become frozen to a large ice floe north of the Laptev Sea. She had on board scientists from 16 countries, who had signed on for a year-long journey with the Transpolar Drift, bound for Fram Strait. A study just released in The Cryosphere has now analysed part of this satellite data gathered during the MOSAiC drift. Read more here…

Moderate Sea-ice Development in the Arctic

19 August 2021
The rate of Arctic sea-ice loss over most of July was relatively low, which makes it increasingly unlikely that a new record-low minimum extent will be reached this September. The seasonal Arctic sea-ice retreat was quite rapid in the first week of July but slowed during the rest of the month. The air temperatures at the 925-millibar level were within roughly 2°C above the long-term average over almost the entire Arctic Ocean. Read more here ...

Arctic sea ice in moderate decline

4 August 2021
Following a moderate decline in sea-ice extent in the Artic in June, the month of July began with a short-term phase of more intensive melting. The low-pressure area that had been dominant over the Central Arctic in May spread across the entire Arctic Ocean in June and reached, at more than 10 hPa below the long-term average, an especially low value. Extremely low air pressure over the Arctic is connected to the positive phase of the Arctic Ocean Circulation and has far-reaching effects on atmospheric circulation patterns, and therefore on climate variability. This weather situation was a crucial element in the heat waves and wildfires in North America and the storms and heavy rains in western Germany and neighbouring countries, which resulted in massive flooding and widespread devastation. Read more here ...

Sea-Ice Situation in the Weddell Sea

An expedition report by Dr Stefanie Arndt

5 July 2021
While the Arctic sea ice continues to decrease, a glance at the Southern Ocean reveals a different picture: in recent years and decades, the sea-ice extent has increased slightly – albeit with clearly recognisable interannual fluctuations and significant regional differences. Investigating the ice situation in the Southern Ocean was one of the aims of the 124th Polarstern expedition (PS124), which took place early this year. One important finding: there were hardly any differences between this year’s measurements and those from previous years! Read more here…

In the Arctic, the transition from spring to summer is largely par for the course

22 June 2021
This May, the sea ice in the Arctic showed average development compared to the past several years. Not until the end of the month did the sea-ice extent substantially decline, dropping below two standard deviations from the average for the period 1981 – 2010. At the same time, the summer solstice was reached in the Northern Hemisphere, which meant the summer’s influence could be felt the most directly, even in the Arctic. The months that follow will be decisive in terms of how the melting in the Arctic progresses and to what extent the sea ice retreats. Read more here ...

A Time-Lapse Video of the MOSAiC Expedition – On-board Radar Images from 300 Days in the Ice

12 May 2021
RV Polarstern is equipped with various marine radar systems. During the MOSAiC expedition, one of these systems’ antennas took a new picture every minute, offering exciting insights into the dynamics of the ice pack in the ship’s immediate vicinity: a time-lapse video of the MOSAiC expedition – a one-of-a-kind sequence compiled using a selection from ca. 2.5 million radar images. Read more here ...

The Unexpected Success Story of a Sea-ice App

22 April 2021
When German coastal researchers head for the North Sea this May to measure the nutrient load in the water and, for the first time, whenever they use a scientific instrument, it is automatically recorded by an app, above all they’ll have the ingenuity of AWI sea-ice engineer Martin Schiller to thank for the new service. After taking part in a several-hour-long search operation in the Arctic, he developed FloeNavi, a system for navigating and locating measuring sites on sea ice. The AWI Computing Centre has since expanded the system’s most popular function, the metadata generator, into a separate app. The AWI’s Data Managers will now make it available to all members of the German Marine Research Alliance – the goal being to make scientific data more transparent and easier to verify. Read more here…

The Arctic Spring Has Begun

14 April 2021
The seasonal maximum sea-ice extent in the Arctic has come and gone, the sun now rises above the horizon again at the North Pole, and the long Polar Night has come to an end. The mean sea-ice extent for March 2021 in the Arctic was 14.72 million square kilometres. In March, the air temperatures at 925 hPa were up to 5 degrees Celsius below average in northern Eurasia, and ranged over Alaska to the east. In contrast, in the Atlantic sector of the Arctic the temperatures were 1 to 3 degrees Celsius above average. After experiencing a prolonged negative phase for the majority of the winter, the Arctic Oscillation was predominantly positive in March, though there were also significant fluctuations. This is indicative of more westerly winds, which bring warmer Atlantic air to Northern Europe. Read more here…

Sea-ice Buoy Retrieved After a Long Trek Across the Arctic

31 March 2021
The thermistor buoy (2018T52) was installed in the Arctic on 14.09.2018, where it continued to transmit data until 04.07.2020. After an impressive journey through the Central Arctic, its return to Bremerhaven makes for an equally exciting story! Thermistor buoys do not float and normally sink into the sea as soon as the ice is no longer able to support their weight. As a result, most of them can’t be recovered and are lost. However, on 04.07.2020, buoy 2018T52 reached Jan Mayen, a small volcanic island roughly 550 km north of Iceland in the Greenland Sea. There it was discovered on a beach by Pål Lunde and Jared Elgvin, head technicians at the weather station in Olonkinbyen, the island’s only settlement. They contacted Jakob Belter from the Alfred Wegener Institute, and sent the case and measuring unit back to Bremerhaven.  Read more here ...

Summer Sea-ice Minimum Reached in the Antarctic

19 March 2021
This year, the sea-ice extent in the Antarctic reached its minimum on 17 February 2021: 2.79 million km². At the same time, there are three regions in which the sea-ice extent is significantly below the long-term average. One is in the northwest Weddell Sea, where the ice edge has retreated far to the south of 65° S. That hasn’t been the case there since 2009.  A second ice-free region in the Weddell Sea is growing to the southeast, in the northern Filchner Trough, where a large polynya has formed, so that there is open water up to the Filchner Ice Shelf. The research icebreaker Polarstern is currently in the region, during Cruise PS124, and is capitalising on the favourable conditions to pursue a comprehensive oceanographic, biological and biogeochemical research programme in the southeast Weddell Sea.
Read more here…

KIT’s “Atlas of Antarctic Sea Ice Motion” now added to the data and information portal

5 March 2021
Continuous datasets from the polar regions are valuable witnesses of the climate change that has become increasingly apparent around the globe since the 1980s. These include data on sea-ice formation and dynamics in the Antarctic pack-ice belt. When the Federal Republic of Germany became a signing member of the Antarctic Treaty in 1979 and established the Georg-von-Neumayer Station, an Antarctic station operated year-round, the stage was set for gathering regular readings in this normally hard-to-access region. In this context the “Atlas of Antarctic Sea Ice Motion” was developed. The KIT’s Atlas of Antarctic Sea Ice Motion was subsequently prepared for its new role as a permanent resource available at the AWI’s, which will also make it possible to combine it with other datasets from after 1998 in the future. Read more here…

Sea-ice Development in Both Polar Regions Largely Normal

15 February 2021
Following 2020, a year that managed to break a number of records in the Arctic, the new year has begun less spectacularly, as a closer examination of the months December and January shows. The current winter season in the Arctic is particularly influenced by the temperature anomaly, which in December produced temperatures up to 5°C above the long-term average for 1971 to 2000 in the Laptev Sea and Central Arctic, and over East Greenland and Northern Canada. The atmospheric circulation linked to this temperature pattern in January was dominated by high pressure over Siberia and low pressure over the northern North Atlantic and North Pacific. Read more here…

DriftStories from the Central Arctic – one year, one floe – sea-ice research to the extreme!

20. Januar 2021
Never before have experts had the chance to investigate the Arctic sea ice as comprehensively as on the international expedition MOSAiC, on board the research icebreaker Polarstern. For an entire year, the ship drifted with the ice through the Central Arctic; for an entire year, the men and women of MOSAiC used cutting-edge technologies to study every facet of the ice around them.

They share the challenges they had to overcome, and what they learned at the polar hotspot of climate change, in the following ten DriftStories, which have now also been collected in the booklet “DriftStories from the Central Arctic”.

You can read the online version of the introduction here.
In addition, you can download the complete booklet as a PDF here or request a printed copy free of charge by mailing us at

Read more here ...