Blar i Geophysical Institute på forfatter "Johannessen, Ola M."
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Arctic climate change: observed and modelled temperature and sea-ice variability
Johannessen, Ola M.; Bengtsson, Lennart; Miles, Martin W.; Kuzmina, Svetlana I.; Semenov, Vladimir A.; Alekseev, Genrikh V.; Nagurnyi, Andrei P.; Zakharov, Victor F.; Bobylev, Leonid P.; Pettersson, Lasse H.; Hasselmann, Klaus; Cattle, Howard P. (Tellus A 56A(4), Peer reviewed; Journal article, 2004-07-09)Changes apparent in the arctic climate system in recent years require evaluation in a century-scale perspective in order to assess the Arctic's response to increasing anthropogenic greenhouse-gas forcing. Here, a new set ... -
Arctic sea ice and climate change - will the sea ice disappear in this century?
Johannessen, Ola M.; Miles, Martin W. (Peer reviewed; Journal article, 2000) -
Climate change in the North – past, present and future
Thiede, Jörn; Johannessen, Ola M. (Journal article; Peer reviewed, 2008)The Nordic countries have produced famous polar explorers and researchers who have generated climate research schools at a variety of locations. The dependence of these countries with respect to the lifelihood of their ... -
Coastal ocean fronts and eddies imaged with ERS 1 synthetic aperture radar
Johannessen, Johnny A.; Shuchman, Robert A.; Digranes, G.; Lyzenga, D. R.; Wackerman, C.; Johannessen, Ola M.; Vachon, P. W. (Peer reviewed; Journal article, 1996-03-15)ERS 1 C band synthetic aperture radar (SAR) data were collected during the Norwegian Continental Shelf Experiment (NORCSEX) both in November 1991 during the ERS 1 commissioning phase and at different seasons in 1992 and ... -
COASTWATCH´95: ERS 1/2 SAR detection of natural film on the ocean surface
Espedal, Heidi A.; Johannessen, Ola M.; Johannessen, Johnny A.; Dano, E.; Lyzenga, D. R.; Knulst, Johan (Peer reviewed; Journal article, 1998-10-15)Ocean mesoscale phenomena such as eddies and current convergence zones can often be seen in synthetic aperture radar (SAR) images due to characteristic patterns caused by natural film induced damping of the waves. Such ... -
Convective chimneys and plumes in the Northern Greenland Sea
Johannessen, Ola M.; Lygre, Kjetil; Eldevik, Tor (Geophysical Monograph Series;30, Chapter, 2005)In the Boreas Basin in the northern Greenland Sea, convection has been observed to be localized as narrow structures - chimneys - in which the water masses may be homogeneous from the surface through great depths. An ... -
Critical vulnerabilities of marine and sea ice–based ecosystems in the high Arctic
Johannessen, Ola M.; Miles, Martin W. (Peer reviewed; Journal article, 2010-12-01)The objectives of this paper are to summarise: (1) observed 20th-century and projected 21st-century changes in key components of the Arctic climate system and (2) probable impacts on the Arctic marine environment, with ... -
Decreasing Arctic Sea Ice Mirrors Increasing CO2 on Decadal Time Scale
Johannessen, Ola M. (Atmospheric and Oceanic Science Letters, Journal article, 2008-11-16)Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO2 since ... -
High northern latitude surface air temperature: comparison of existing data and creation of a new gridded data set 1900–2000
Kuzmina, Svetlana I.; Johannessen, Ola M.; Bengtsson, Lennart; Aniskina, Olga G.; Bobylev, Leonid P. (Peer reviewed; Journal article, 2008-03)Detection, attribution and understanding of temperature changes in the high northern latitudes depend on constraining uncertainties and resolving apparent discrepancies in observational data sets. We quantitatively compare ... -
High-frequency internal wave observations in the marginal ice zone
Sandven, Stein; Johannessen, Ola M. (Journal of Geophysical Research: Oceans;92(C7), Journal article, 1987-06-30) -
The North Atlantic Oscillation and greenhouse-gas forcing
Kuzmina, Svetlana I.; Bengtsson, Lennart; Johannessen, Ola M.; Drange, Helge; Bobylev, Leonid P.; Miles, Martin W. (Peer reviewed; Journal article, 2005-02-17)The results of 12 coupled climate models participating in the Coupled Model Intercomparison Project (CMIP2) are compared together with observational data in order to investigate: 1) How the current generation of climate ... -
Observation and Simulation of Ice Tongues and Vortex Pairs in the Marginal Ice Zone
Johannessen, Ola M.; Sandven, Stein; Budgell, W. Paul; Johannessen, Johnny A.; Shuchman, Robert A. (Geophysical Monograph 85, Chapter, 1994)Recognizes the major advancements of the past decade in understanding the interactions among the polar oceans and global atmospheric and oceanic systems. This volume addresses the following topics: Polar Ocean Circulation ... -
Simulating transport of non-Chernobyl 137Cs and 90Sr in the North Atlantic–Arctic region
Gao, Yongqi; Drange, Helge; Bentsen, Mats; Johannessen, Ola M. (Peer reviewed; Journal article, 2004)The spatial and temporal distributions of the anthropogenic radionuclides 137Cs and 90Sr, originating from nuclear bomb testing and the Sellafield reprocessing plants in the Irish Sea, are simulated using a global version ... -
Tracer-derived transit time of the waters in the eastern Nordic Seas
Gao, Yongqi; Drange, Helge; Bentsen, Mats; Johannessen, Ola M. (Peer reviewed; Journal article, 2005-08-25)The spatial-temporal distribution of the anthropogenic radionuclide 137Cs originating from nuclear bomb testing and the Sellafield reprocessing plant in the Irish Sea is simulated using a global version of the Miami Isopycnic ... -
Wintertime cyclone/anticyclone activity over China and its relation to upper tropospheric jets
Chen, Lei; Tan, Benkui; Kvamstø, Nils Gunnar; Johannessen, Ola M. (Peer reviewed; Journal article, 2014-01-16)In this study, the wintertime cyclone/anticyclone activity and its variability over China are examined based on the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis ...