At the end of August, an unusual expedition under Russian leadership will leave for the Arctic Ocean. One of the participants is Jürgen Graeser of the Alfred Wegener Institute for Polar and Marine Research, one of the research centres of the Helmholtz Association. For the first time in the history of Russian research using drifting stations, a German researcher will take part in the North Pole drifting station NP-35.
With his data recordings of the atmosphere, Graeser will supplement measurements carried out by the Russian project partners, who will be focusing their investigations on sea ice, primarily performing measurements close to the ice. Through this collaboration, the project partners intend to advance the currently patchy data situation in the Arctic and hope to gain a better understanding of these key regions for global climate change.
Experience with regular Russian drifting stations in the pack ice dates back to 1952 when the research station NP-2 was launched. Whereas previous drifting stations were dedicated exclusively to Russian research, the international station planned within the framework of the International Polar Year will, for the first time, include a German participant of the Alfred Wegener Institute, Jürgen Graeser. The planned project will be carried out in conjunction with the Arctic and Antarctic Research Institute (AARI) in St Petersburg. On August 29, 2007, a total of 36 expedition participants will board the Russian research vessel ‘Akademik Fedorov’ in the Siberian harbour of Tiksi.
In the vicinity of Wrangel Island, i.e. between 80 and 85 degrees northern latitude and between 170 degrees eastern and 170 degrees western longitude, a stable ice floe will be chosen as the base for the drifting station ‘North Pole 35’ (NP-35). The selection will be based on long-term satellite observations of the ice and will be verified by helicopter from the research vessel. During the course of winter, the ice floe will drift in the Arctic Ocean and across the North Pole. During the drift, a variety of measurements carried out at the station will provide information about current climate change. The ‘Akademik Fedorov’ is scheduled to evacuate the station after approximately one year. With regard to over-wintering personnel, it is planned to use ‘Polar 5’, the research aircraft of the Alfred Wegener Institute, to fly out Jürgen Graeser and five Russian colleagues after approximately eight months, in April 2008. For this purpose, a landing strip will be constructed on the ice.
The research programme
The Russian colleagues will be investigating the upper ocean layer and sea ice, as well as snow cover. Atmospheric measurements of meteorological parameters such as temperature, wind, humidity and air pressure, will be added through recordings of trace gases such as carbon dioxide and ozone. Jürgen Graeser will examine two topics. On the one hand, he will use a captive balloon system to measure meteorological parameters in the so-called planetary boundary layer, which is the lowest layer of the atmosphere extending to approximately 1500 metres. In addition, he will use ozone sensors to measure the ozone layer in the stratosphere up to approximately 30 kilometres altitude.
Jürgen Graeser has been a technician at the research unit Potsdam of the Alfred Wegener Institute and has many years of experience with Arctic and Antarctic expeditions. His special areas of interest are aerology and meteorology. His expertise includes balloon-based, radiation and meteorological measurements.
The Arctic represents a key region for global climate change. Measurements of sea ice and atmospheric parameters in the Arctic Ocean are still incomplete. Through the current project, researchers intend to identify key processes in the atmosphere and alterations of the sea ice cover in order to examine the coupling of sea ice and atmosphere. The project is one of many during the International Polar Year. More than 50,000 scientists and technical staff from over 60 countries are joining force to explore the polar regions. Their goal is to study the role of the Arctic and Antarctic in shaping the climate and the earth’s ecosystems.
Project ‘Planetary Boundary Layer’
The planetary boundary layer (PBL) identifies the lowest atmospheric layer, extending from the surface to approximately 1500 metres altitude. In the Arctic, this layer is characterised by frequent temperature inversions, i.e. by very stable atmospheric stratification which suppresses vertical movements of the air. A realistic representation of the planetary boundary layer is crucial for the construction of climate models, as it is this layer that determines the lower marginal conditions for all calculations. Particularly, the investigation of processes influenced directly by the boundary layer, requires exact knowledge of the state of the PBL.
AWI scientists in Potsdam use the regional climate model HIRHAM to construct mesoscale fields of pressure, temperature and wind in which cyclones (low pressure regions) and their trajectories are identified. Specifically, they are examining the relationship between cyclone development and various surface conditions (e.g. sea ice cover). Elucidating the connection between the Arctic planetary boundary layer and mesoscale cyclones and their trajectories is the goal of these investigations.
Project ‘Ozone Layer’
Discovery of the Antarctic ozone hole in 1985 triggered intensive exploration efforts of the polar ozone layer. This layer is located between 15 and 25 kilometres altitude in the stratosphere. Many chemical processes of ozone depletion in the Antarctic have since been explained, and the connection of ozone destruction with anthropogenic emissions of chlorofluorocarbons (CFCs) and halons has been proven beyond doubt.
During specific winters, severe ozone losses over the Arctic, and hence much closer to home, have already contributed to a reduction in ozone layer thickness over Europe – leading to an increase of harmful ultraviolet radiation on the earth’s surface. However, to date the ozone depletion in the Arctic is not as pronounced as over the Antarctic. Compared to the Arctic, ozone layer thickness in the Antarctic is much more variable, with only about half of the observed inter-annual variability explained by known chemical mechanisms. Hence, dynamic processes which remain only partly understood are equally important in determining thickness of the ozone layer over the Arctic as the chemical decomposition of ozone.
At the Arctic station of the Alfred Wegener Institute in Ny Ålesund on Spitsbergen (79°N), for instance, a strong annual ozone variation of 30 percent was detected at an altitude of 25 to 30 kilometres. Apparently, it is synchronised with variability of the sun, but cannot be explained by known chemical or other dynamic processes. Investigating the cause of this variability will be the focus of ozone measurements at NP-35. Data records from the drifting station will, for the first time, produce high resolution vertical profiles of ozone distribution in the central Arctic, north of 82 degrees latitude – currently a blank spot on the global ozone distribution map. These unique data will be combined with existing ozone profiles from the Arctic and Sub-Arctic. Calculations of air movement in conjunction with chemical models will contribute to an understanding of seasonal and annual variability of stratospheric ozone in the Arctic.
Angelika Dummermuth | EurekAlert!
Research sheds new light on forces that threaten sensitive coastlines
24.04.2017 | Indiana University
NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | NASA/Goddard Space Flight Center
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
24.04.2017 | Physics and Astronomy
24.04.2017 | Materials Sciences
24.04.2017 | Life Sciences