• Sea Ice Physics

    ice influence the observed variability of Arctic and Antarctic sea ice? How do variations in melt and freeze rates impact the ocean and the atmosphere in the Arctic and Antarctic? What are the consequences [...] polar ocean due to Arctic sea ice retreat? We apply, improve, and develop various methods to study sea ice and snow processes in both hemispheres, including the interaction of atmosphere and ocean. Contact [...] are the reasons for the dramatic changes in Arctic sea ice during the last decades? Why is the development of sea ice in the Antarctic so different to the Arctic and shows strong regional differences? How

  • Ultraslow spreading mid-ocean ridges

    category of mid-ocean ridges, accounting for about 15% of the total length of mid-ocean ridges worldwide. Since ultraslow ridges are located in the Arctic Ocean and the stormy Southwest Indian Ocean and are therefore [...] Ultraslow spreading mid-ocean ridges At mid-ocean ridges, the lithospheric plates move apart at rates of about 5-150 mm/year and new oceanic lithosphere is continuously formed. At low spreading rates of [...] making its way to the ocean floor through a cold, thick lithosphere. Therefore, the formation process of new ocean lithosphere differs at ultraslow spreading ridges from all other ocean basins. Ultraslow ridges

  • Pre-Quaternary

    stratification in the Arctic Ocean during the Miocene , arktos . doi: 10.1007/s41063-020-00079-8 Lohmann, G. , Knorr, G. , Hossain, A. and Stepanek, C. (2022): Effects of CO2 and Ocean Mixing on Miocene and [...] in the ocean model FESOM. The figure shows a land-sea configuration during the Middle Miocene (~15 million years ago) as incorporated in a complex Earth System Model. For example changes in oceanic gateways [...] between classic hypotheses for glaciations that involve e.g. tectonic changes and associated changes in ocean circulation or declining atmospheric CO 2 in combination with the Earth’s orbital configuration. Research

  • Projects

    Schepper What are the global impacts of an ice-free Arctic? How will the Arctic develop with increasing climate warming? What does an ice-free Arctic mean for our environment and our society? Researchers [...] surface uplift of the Andes, but also by changes in the oceanic circulation of the adjacent Pacific Ocean. The timing, forcings, and feedbacks of land-ocean coupling and their impact on the past hydroclimate [...] feedback mechanisms in the Arctic affect the phase shift of Arctic surface temperature. The function of each feedback will be quantified for understanding the physical processes of Arctic amplification underlying

  • Automatic Weather Stations

    (AWS) In addition to the long-term measurements in Antarctica, ( Neumayer_III ), in the Arctic (AWIPEV ) and on the oceans ( Polarstern ) automatic weather stations (AWS) are in use. The numbers of the AWS-systems

  • Long-term Observation of Surface Radiation

    Radiation in the Arctic (AWIPEV Research Base in Ny-Ålesund, Spitsbergen) Pyranometer in Ny-Ålesund. (Photo: Alfred-Wegener-Institut) Ny-Ålesund is situated 78.9° N north of the arctic circle. During the [...] fundamental role in determining the thermal conditions and the circulation of the atmosphere and the ocean, shaping the main characteristics of the Earth's climate. The radiation budget components at the surface

  • Publications

    1126/science.adp3491 Gou, R., K. Wolf, C. Hoppe, L. Wu, G. Lohmann, 2025: The changing nature of future Arctic marine heatwaves and its potential impacts on the ecosystem. Nature Climate Change, doi.org/10 [...] Lohmann G, Boers N, Daniau AL, Oliveira RS, Campos MC, Shi X, De Oliveira PE, 2014: Slowdown of ocean circulation increases the vulnerability of northern Amazon forests. Nature Geoscience 2024. DOI: 10 [...] and M. Kucera, 2023: Plankton biogeography shows strong meridional variation in ice age to modern ocean warming. Nat. Geosci., DOI:10.1038/s41561-023-01328-7 2022 Pontes, G., A. Taschetto, A. Sen Gupta

  • Technology and Logistics

    backbone of the Global Ocean Observing System (GOOS) is the Argo system, which uses an array of >3000 profiling floats (Figure 2). Until recently, Argo was restricted to ice free oceanic regions, as the floats [...] Technology and Logistics Observations of the ocean’s temperature and salinity at different locations and depths – key parameters to assess its state - depended until recently on ship-based expeditions [...] and deep-sea moorings, limiting our ability to monitor oceanic change at adequate resolution and over necessary periods in time and space. However, with the turn of the century, automated systems gained

  • Fram Strait

    current long-term observations Atlantic Water is the main oceanic source of heat, salt, and nutrients of the Arctic Ocean. It enters the Arctic Ocean through the Barents Sea or Fram Strait. In the eastern [...] recirculates to the western Fram Strait on timescales of several months while the rest enters the Arctic Ocean and follows a cyclonic circulation for years to decades. The AWI long-term observations in Fram [...] around 4°C since. Two anomalous warm events occurred in fall 2006 and in late winter 2012. In the deep ocean, it was also observed that the two water masses present there (the warmer Eurasian Basin Deep Water

  • Central Arctic

    from the Arctic reservoir. Long-term observations in the Arctic Ocean by a multitude of observational platforms allow estimates of annual mean liquid freshwater content in the upper Arctic basins (Figure [...] Central Arctic long-term observations [Translate to English:] Anomalies of annual mean liquid freshwater content in the upper Arctic Ocean basin from salinity profile observations since 1992. Liquid freshwater [...] linear trend is 600+-300 The central Arctic is an important component of the global climate system, not only by atmospheric teleconnections but also by links in ocean circulation to lower latitudes. There