Description: Based on a sediment vibro corer, a tool for the sampling of sub-seafloor groundwater aquifers has been developed and successfully deployed in a coastal area of the western Baltic. The device was designed to obtain pure groundwater samples from coarse sediments to be used for tracer investigations and CFC age dating. Operated from a medium size research vessel, a well pipe tipped with a filter segment is vibrated into the sediment down to the aquifer. Groundwater entering the filter is pumped to the ship by a conventional submersible pump situated in the well's filter tip. Groundwater is continuously analysed on board for O2, salinity, pH, Eh and temperature, prior to sampling for CFC and radioisotope analysis. All parameters indicate that pure groundwater had been obtained. CFC concentrations are very low suggesting that the groundwater of this shallow sub-seafloor aquifer recharged prior to 1950. This finding is in accordance with other hydrogeological evidence that this aquifer, located only 4–5 m below the seafloor, is connected to fairly deep confined sandy aquifers on land of Pleistocene or Miocene age. Applying the method described, it is possible to obtain sufficient sample volumes for analyses of natural groundwater tracers such as radon-222 and CFCs which can be used to trace submarine groundwater discharge as well as the origin of groundwater in such environments.

Description: During the RV Polarstern ANT XXIV-2 cruise to the Southern Ocean and the Weddell Sea in 2007/2008, sediment samples were taken during and after a phytoplankton bloom at 521S 01E. The station, located at 2960 m water depth, was sampled for the first time at the beginning of December 2007 and revisited at the end of January 2008. Fresh phytodetritus originating from the phytoplankton bloom first observed in the water column had reached the sea floor by the time of the second visit. Absolute abundances of bacteria and most major meiofauna taxa did not change between the two sampling dates. In the copepods, the second most abundant meiofauna taxon after the nematodes, the enhanced input of organic material did not lead to an observable increase of reproductive effort. However, significantly higher relative abundances of meiofauna could be observed at the sediment surface after the remains of the phytoplankton bloom reached the sea floor. Vertical shifts in meiofauna distribution between December and January may be related to changing pore-water oxygen concentration, total sediment fatty acid content, and pigment profiles measured during our study. Higher oxygen consumption after the phytoplankton bloom may have resulted from an enhanced respiratory activityof the living benthic component, as neither meiofauna nor bacteria reacted with an increase in individual numbers to the food input from the water column. Based on our results, we infer that low temperatures and ecological strategies are the underlying factors for the delayed response of benthic deep-sea copepods, in terms of egg and larval production, to the modified environmental situation.

Description: Organic carbon (OC) burial is an important process influencing atmospheric CO2 concentration and global climate change; therefore it is essential to obtain information on the factors determining its preservation. The Southern Ocean (SO) is believed to play an important role in sequestering CO2 from the atmosphere via burial of OC. Here we investigate the degradation of organic-walled dinoflagellate cysts (dinocysts) in two short cores from the SO to obtain information on the factors influencing OC preservation. On the basis of the calculated degradation index kt, we conclude that both cores are affected by species-selective aerobic degradation of dinocysts. Further, we calculate a degradation constant k using oxygen exposure time derived from the ages of our cores. The constant k displays a strong relationship with pore-water O2, suggesting that decomposition of OC is dependent on both the bottom- and pore-water O2 concentrations.

Description: For a responsible development of the Arctic, new remote sensing technologies and services are of great importance. Many of such innovations are based on scientific research. However, it is not trivial that they find their way into application. In order to ease this kind of transfer across the interface between academia and industry, the Alfred Wegener Institute has established a technology transfer office (TTO). The TTO takes up inventions and business ideas emerging from scientific research and supports innovators and entrepreneurs to progress them into the respective markets. The other way round, the TTO serves as the contact point for stakeholders from industry, governmental and non-governmental bodies to forward specific problems into the scientific community. Here we present two examples to illustrate the AWI technology transfer approach: 1) Planned for 2022, the German hyperspectral earth observation satellite EnMAP (Environmental Mapping and Analysis Programme) will measure the reflected radiance from the earth’s surface over a wide hyperspectral wavelength range (from visible to short wave infrared). In order to provide correct hyperspectral satellite products such as land cover (natural surfaces, urban), surface waters, surface mineralogy, hydrology (snow, moisture) etc. in a correct manner, it is necessary to normalize for the incidence and the reflection of light depending on the zenith and azimuth viewing geometries. This is performed by providing the bidirectional reflectance distribution function BRDF for different materials. Determination of BRDFs for terrestrial surfaces is very challenging especially for high latitudes due to the low solar altitude. For Arctic vegetation mapping, a specific satellite field goniometer was developed at AWI to perform such ground truthing (Buchhorn et al., 2013). The goniometer allows for mobile ground-based measurements in order to determine the BRDF for different vegetation types. It consists of an azimuth angle adjustment module mounted on a tripod with a zenith arc with sensor sled equipped with two portable spectro-radiometers, a GPS receiver, an NC-Eye camera system and a white reference panel. The goniometer was prototyped, patented and licensed to a precision mechanics manufacturer. The commercial system in this case addresses the scientific community and specialized service providers. 2) Starting with geophysical ice thickness measurements on sea-ice and using air-borne electromagnetic measuring systems (Krumpen et al. 2011) a group of AWI scientists developed specific sea-ice related services for scientific, governmental and private sector customers operating in Arctic sea-ice. Subsequently the AWI spin-off Drift & Noise Polar Services was established in 2014. The new business was developed towards near real-time remote sensing ice information products and sea-ice consultancy for safer and faster navigation through ice-covered waters. Ice charts and weather information are generated from SAR and optical imagery (e.g. Sentinel 1 and 2). Since reliable broadband data transfer channels do not exist, particularly for high latitudes, the start-up also develops appropriate data compaction and transfer protocols combined with hand-held mobile systems for nautical officers which allow for near real-time access to latest ice data onboard ship. Thus shipping companies are able to save time and fuel by adapting their route while increasing safety. Fig. 1: Portable field spectro-goniometer for EnMAP ground truthing (a). Hand-held sea-ice information system “Ice Pad” using merged optical and SAR imagery (b). References 1. M. Buchhorn, R. Petereit & B. Heim (2013) A Manual Transportable Instrument Platform for Ground-Based Spectro-Directional Observations (ManTIS) and the Resultant Hyperspectral Field Goniometer System. Sensors, 13 (12), 16105-16128, doi:10.3390/s131216105. 2. T. Krumpen, L. Rabenstein, & J. Hoelemann (2011) Quantifying Sea Ice Formation Rates in the Laptev Sea by Means of ENVISAT SAR Scenes and Airborne Ice Thickness Measurements. International Union of Geodesy and Geophysics (IUGG) General Assembly, Melbourne, Australia, 29 June 2011 - 7 July 2011, hdl:10013/epic.38551.