Fridtjof Nansen's contribution to modern oceanography Ola M Johannessen Nansen Environmental and Remote Sensing Center, Bergen, Norway [email protected]

After crossing Greenland, discovering that the interior of the Greenland was completely covered by an ice sheet, Nansen started to plan the daring Fram expedition, 1883-1896. Nansen observed that the Arctic Ocean was more than 4000 m deep. Furthermore he observed that the icepack with Fram drifted to the right of the wind direction and that this for the first time could be explained by the “deflecting force arising from the Earth’s rotation”, which in modern times became the fundamental concept for the wind driven current and upwelling in the coastal region and the World Oceans. Nansen next contribution to modern oceanography was a systematic investigation in the Norwegian Sea during the 5 years 1900-1904 together with Bjørn Helland Hansen. Here they pioneered the circulation of the Norwegian Sea, the deep water formation and the mesoscale eddy circulation which became a model for similar investigation in modern times. Examples of the importance of Nansen’s legacy for modern physical oceanography will be shown both for the Arctic, the Norwegian Sea and the World Ocean. Short biography Ola M. Johannessen (OMJ) is presently involved in the following scientific fields: Global warming detection and prediction of the Arctic climate system, including sea ice, Greenland ice sheet variability, radioactive spreading in the Nordic Seas and the Arctic Ocean, Indian and Southern Ocean circulation studies and socio-economic impact studies of global change. OMJ is the author and co-author of 500 publications of which 8 are books and 137 are in refereed journals. He has received 9 awards for his research and leadership. He was the Laureate of the EU Descartes Prize in Earth Science in 2005 for leading the project: Climate and Environmental Change in the Arctic (CECA). He received the Fridtjof Nansen Medal for Outstanding Research in 2007, furthermore His Majesty King Harald V of Norway appointed OMJ to the Royal Norwegian St. Olav’s decoration, Knight of first class, 24 of November 2008. In 2010 he was awarded the honorary membership from the Norwegian Academy of Technological Sciences, NTVA. OMJ took the initiative to start the Nansen Group which today consist of Nansen Centers in Bergen, Norway – St. Petersburg, Russia – Cochin, India – Beijing, China and Cape Town, South Africa. Today the Nansen Group has a staff of 200 including 75 PhD and Master Students. OMJ is elected full member of the International Academy of Astronautics, the European Academy of Science and Arts, Finnish Academy of Science and Letters, the Norwegian Academy of Technical Sciences and the Norwegian Academy of Science and Letters and the Norwegian Scientific Academy for Polar Research where he also is the President.

The Arctic Sea Ice - status and projections Jan-Gunnar Winther Norwegian Polar Institute, Tromsø, Norway [email protected]

Rapid sea ice loss is one of the most prominent indicators of global climate change. Sea ice extent in the Arctic has shrunk by more than 35 % since 1979, with the lowest amounts of ice observed in the last four summers: 2007, 2008, 2010 and 2009 (http://nsidc.org). An Arctic summer with nearly ice-free conditions may be expected before mid-century. Winter sea ice extent is also expected to become smaller, although not at the same rate as in summer. There is less multi-year sea ice and in some regions sea ice is thinning (Kwok et al., 2009; Haas et al., 2008). At the end of the summer 2010, under 15 % of the ice remaining in the Arctic was more than two years old, compared to 50 to 60 % during the 1980s (http://nsidc.org). Sea ice cover is diminishing significantly faster than climate model predictions. Feedback mechanisms due to a decline of sea ice are poorly resolved in climate models. The presentation will give a status of the development of Arctic sea ice conditions, including projections for future development and its potential effects. Short biography Ph.D. (and M.S.) from the Norwegian Institute of Technology (NTH) in 1993. Ph.D.-thesis with emphasis on surface albedo of snow and glacier ice using satellite data from Antarctica, Svalbard and Norway. Scientist at NTH in 1998, in SINTEF from 1989 to 1994 and since then at the Norwegian Polar Institute (NPI). Various positions within NPI including Head of the Antarctic Section, Head of Polar Climate Programme, Research Director and Director since 1995. Adjunct Professor at the University Centre in Svalbard (UNIS) from 2002- 2007. Leader course at the Norwegian National Defence College (“Forsvarets høgskole”) in 2003.Winther has served on a number of national and international committees and delegations including deputy chair of the Norwegian Government’s Expert Committee on Northern Regions Policies, national expert to Arctic Council and the Antarctic Treaty Consultative Meetings, member of the Norwegian Academy of Technological Sciences and the Explorers Club and lead author on IPCC’s Fifth Assessment Report.

The Puzzles of Sea Level Change Carl Wunsch Massachusetts Institute of Technology (MIT) [email protected]

Traditionally, from the point of view of the physical oceanographer, sea level rise, past and present, was a peripheral, somewhat tedious subject. In a world undergoing warming, this subject is suddenly of intense interest, with the past and present changes used to illuminate the question of future rise. In practice, understanding sea level change as a scientific problem raises a remarkable number of interesting and difficult questions ranging across a huge variety of problems and fields, including the behavior of ice sheets, the response of the ocean to shifting winds, the hydrological cycle generally, the calibration standards of satellites, the understanding of paleosea level, the adequacy of ocean circulation models, and many more. I will range across some of these subjects with an emphasis on how much is understood of what is going on today. Short biography Carl Wunsch is Cecil and Ida Green Professor of Physical Oceanography at Massachusetts Institute of Technology. He holds a bachelor’s degree in mathematics and a PhD in geophysics, both from MIT. He has worked on many aspects of physical oceanography and its climate implications, with emphasis on global-scale including satellites and acoustic tomographic methods. He was an organizer of the World Ocean Circulation Experiment, chaired the science committees leading to the flight of altimetric satellites, and is deeply involved in the analysis of the results including the use of general circulation models. He is a member of the National Academy of Sciences, a foreign member of the Royal Society of London, a Fellow of the American Academy of Arts and Sciences, American Philosophical Society, American Geophysical Union and American Meteorological Society and has received a number of awards.

Antarctic Bottom Water propagation in the Atlantic Eugene Morozov Shirshov Institute of Oceanology, Moscow, Russia [email protected]

The lecture is dedicated to the study of structure and transport of Antarctic Bottom Water through abyssal channels of the Atlantic Ocean. The study is based on recent observations, analysis of historical data, and literature review. When speaking about the ocean, the main interest is generally focused on the processes at the ocean surface. However, the ocean is a three-dimensional structure and the processes in the ocean deep are not less interesting and important. Water at the surface is cooled in the polar regions and slowly sinks to the bottom. Thus, the water that was formed in the Antarctic propagates to the north at the bottom of the deep basins of the Atlantic Ocean and reaches the deep basin west of Europe maybe in 200 years. The ocean basins are separated by underwater ridges with deep fractures crossing them, which become the pathways for the bottom water propagation. The velocity of the bottom water flow in the deep channels can be as high as 60 cm/s. Underwater waterfalls were found in the deep oceanic channels. The flow of water in submarine waterfalls exceeds the transport of the Amazon River and the descent of water can be as high as 500 m. Short biography Eugene Morozov is Doctor of Sciences in Physics and Mathematics, Head of Laboratory at the Shirshov Institute of Oceanology in Moscow, Russian Academy of Sciences. Eugene Morozov has been working at the Shirshov Institute since 1970. The main fields of his research are internal waves and ocean circulation. He is a field oceanographer, and his work includes field measurements, data collecting, processing and analysis. The main result of his research is discovery of the fact that the main source of internal tide generation is interaction between the barotropic tide and submarine ridges. Previously it was considered that the major generation occurs over continental slopes. He constructed a chart of internal tide amplitudes in the World Ocean. He demonstrated that approximately a quarter of the barotropic energy dissipation is spent on the generation of internal tides over submarine ridges. These results were published in: E. Morozov Semidiurnal internal wave global field, Deep Sea Research, vol. 42, No 1, 1995, 135-148. The recent scientific activity of E. Morozov is related to the flows in the abyssal channels of the Atlantic: Vema Channel, Romanche and Chain fracture Zones, Kane Gap, Vema Fracture Zone, and others. These results were published by Springer in: E. Morozov, A. Demidov, R. Tarakanov, W. Zenk, Abyssal Channels in the Atlantic Ocean: Water Structure and Flows, Springer, 2010. Eugene Morozov is the author of 173 publications including four books. Since 1969 E. Morozov made 38 cruises in the ocean including 25 cruises in the Atlantic, 4 cruises in the Indian, 4 cruises in the Pacific, 4 cruises in the Southern and one cruise in the Arctic Ocean. In many of them he was the leading scientist. In 2007, Eugene Morozov was elected a vice-president of the International Association for Physical Sciences in the Ocean.

Global modelling of internal tides Stephen D Griffiths University of Leeds, UK [email protected]

Tides occur throughout the oceans, most prominently as oscillations with semi-diurnal or diurnal timescales. Forced by the Sun and Moon, the primary response is a surface tide with deep horizontal flows accompanied by familiar sea-surface displacements. However, as the density-stratified ocean interior is moved up-and-down by tidal flow over topography, internal gravity waves of tidal frequency are generated. These internal tides are almost invisible at the ocean surface, but can lead to vertical displacements of 50m or more in the ocean interior. The generation of internal tides leads to an important energy transfer from the surface tide, and is thus a process of planetary scale relevance, with implications for the large-scale distribution of heat in the ocean and the evolution of the lunar orbit. On a global scale, observational estimates suggest that internal tide generation requires a power input of about 1TW, and thus accounts for about one-third of the dissipation of the surface tide (the rest being associated with bottom friction). Here, high-resolution numerical modelling is used to understand internal tide generation on a global scale, and to make direct estimates of the associated energy transfer from the surface tides. This kind of approach, when coupled with numerical modelling of the surface tide, also offers the possibility of exploring tides during the ice-ages of the late Quaternary, during which the tidal regime shifted due to changes in the geometry of the ocean basins. Short biography Stephen Griffiths is an applied mathematician, with primary research interests in the fluid dynamics of the Earth's atmosphere and ocean. He obtained undergraduate degrees in mathematics from the University of Cambridge, before completing a PhD there in 2001, within the Department of Applied Mathematics and Theoretical Physics. He then held research appointments in the Department of Mathematical Sciences at the University of Loughborough (UK), the Department of Atmospheric Sciences at the University of Washington (USA), and the Department of Physics at the University of Toronto (Canada), variously working on linear and nonlinear waves, the dynamics of the equatorial stratosphere, ocean tides and internal waves, and paleoceanography. In 2008, he became a lecturer in applied mathematics at the University of Leeds, UK, where he continues to work on developing mathematical and numerical models in these and other research areas.