NERSC News Archive

New paper by Dumont et al. in JGR: "A wave-based model for the marginal ice zone including a floe breaking parameterization. "

A simple but novel parameterization for floe breaking is derived by considering alternatively ice as a flexible and rigid material and by using current estimates of ice flexural critical strain and strength. This parameterization is combined with a wave scattering model in a one-dimensional numerical framework, to evaluate the floe size distribution and the extent of the MIZ.

http://www.agu.org/contents/journals/ViewPapersInPress.do?journalCode=JC

New Paper by Keghouche et al in JGR: "Modeling dynamics and thermodynamics of icebergs in the Barents Sea from 1987 to 2005"

A modeling study of iceberg drift characteristics in the Barents and Kara seas for the period 1987–2005 is presented. Maps of iceberg density and potential locations subject to grounding complement sparse existing oceanographic and aerial field survey campaigns.

The model suggests preferential pathways from the most important calving sources. Icebergs originating from Franz Josef Land have the largest spread over the domain. Simulations confirm the previously observed seasonal cycle of the southernmost extent of the icebergs.

Luftkvaliteten i Bergen

Høytrykkssituasjonen over sør Norge i slutten av november og begynnelsen av desember har gitt værforhold i de siste ukene som kalles atmosfærisk blokkering. Under slike atmosfæriske blokkeringer er det hovedsakelig østlig og nordøstlig svake vinder og derfor mye klart vær og den vanlige vestvinden med nedbør uteblir. Slike blokkeringer ble hyppig observert i januar-februar 2010 i Bergen og de kom tilbake igjen fra midten av november – kanskje litt uvanlig for denne årstiden.

Air quality in Bergen during atmospheric blocking situations

Atmospheric conditions observed during late November and early December last year in Bergen are known as the atmospheric blocking. During days with blocking, easterly and north-easterly weak winds prevail. In Bergen, blocking situations have been frequently observed in January-February 2010 and return now in November. Blocking, as a meteorological phenomenon, causes large public resonance as its persistence over several days and even weeks deteriorate the air quality in some parts of the city.

Publication on the vulnerabilities of marine and sea ice–based ecosystems

The paper “Critical vulnerabilities of marine and sea ice–based ecosystems in the high Arctic” has been published in Regional Environ Change.

The objectives of the 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 emphasis on the vulnerabilities of marine and sea ice–based ecosystems.

Nansen-Tutu Centre scientific opening seminar

The scientific opening seminar for the Nansen-Tutu Centre for Marine Environmental Research has during the last days gathered 90 scientist and students in Cape Town, South Africa. The seminar is organized in collaboration with Centre for High Performance Computing in South Africa.

The seminar focus on the research challenges in monitoring and predicting ocean state in the waters surrounding South Africa where strong cold and warm ocean currents interacts, periodic upwelling occurs and with a complex, diverse and vulnerable marine ecosystem.

Doctoral dissertation on data assimilation in oil reservoir modeling

Dr. Alexandra Seiler has very successfully defended her Ph.D. thesis ”Reservoir Structural Model Updating Using the Ensemble Kalman Filter” at the Faculty of Science at University of Bergen. The work has been performed at the Nansen Center and Statoil ASA, within the Research Council of Norway eVita project coordinated by the Nansen Center.

Chinese Academy of Sciences Appointment

Professor Ola M. Johannessen, executive chairman of the Board of the Nansen Environmental and Remote Sensing Center in Bergen, Norway was appointed ”Visiting Professor for Senior International Scientists of the Chinese Academy of Sciences (CAS)” for 2010. The diploma, signed by Prof. Lu Yongxiang, President of the Chinese Academy of Sciences, was presented to him by Prof. Hui-Jun Wang, Director for ”Institute of Atmospheric Physics of CAS” in Beijing on Tuesday October 26th. Prof. Johannessen delivered then his first guest lecture titled ”Arctic climate, present and future perspectives”.

Administrasjonssjef stilling ledig ved Nansensenteret

Nansensenteret søker en administrasjonssjef som skal ha ansvar for senterets administrative funksjoner, kontraktsoppfølging og personalforvaltning. Stillingen inngår i senterets ledergruppe og rapporterer til direktør.

Vi søker etter en person med ledererfaring og relevant høyere utdannelse.

Doctor of Science dissertation at NIERSC

On September 30 Dr. Vitaly Alexandrov at Nansen Environmental and Remote Sensing Centre (NIERSC) in St. Petersburg successfully defended his Doctor of Sciences thesis in Oceanography. The title of his thesis is "Satellite radar monitoring of the Arctic sea ice".

The defense was carried out at the Scientific Council of Arctic and Antarctic Research Institute, headed by Dr. I. Frolov. The official opponents were Professor G.A. Lebedev (AARI), Professor V.I. Binenko (Center of Ecological Safety of RAS/State Russian Hydrometeorological University), and Professor A.V.

Minister of research and higher education visited the Nansen Center

The Norwegian Minister of research and higher education Tora Aasland visited the Nansen Center to day after she had opened “Forskningsdagene” here in Bergen.

Prof. Ola M. Johannessen informed the Minister about new research results and observations on studies of the Greenland ice sheet melting and accumulation.

Minimum sea ice extent in the Arctic now

In the middle of September every year the minimum sea ice extent appears in the Arctic Ocean – so also this year. Both the Northeast- and Northwest- passages are ice free and open for ship traffic. According to the ArcticROOS analysis of satellite microwave data the minimum sea ice area occurred on September 8th 2010 with an ice area of 4.12 mill. km2 in the Arctic Ocean. The sea ice area was then 16% larger that the previous minimum observed in 2007.

The ice area during the 2010 minimum ice extent in the Arctic Ocean (Figure 1) is 4.12 mill.

Vacant PhD position in satellite remote sensing of the cryosphere

A PhD position in satellite remote sensing of cryosphere is vacant at the Nansen Environmental and Remote Sensing Center, Bergen, Norway. The position will focus on development of methodology for use of CryoSat-2 radar altimeter data for Arctic land and sea ice studies. Furthermore, the PhD work will include analysis of CryoSat-2 data in combination with other satellite data such as SAR to study sea ice volume and fluxes in the Arctic. The PhD candidate will have opportunity to spend some of the time at the Nansen Center’s office in the Science Park in Longyearbyen.

Impact of anticyclonic eddies on the primary production in the Norwegian Sea.

In the September issue of Deep Sea Research Cecilie Hansen, E. Kvaleberg and Annette Samuelsen publish the paper “Anticyclonic eddies in the Norwegian Sea; their generation, evolution and impact on primary production”.

In the paper they use satellite radar altimetry and ocean color observations in combination with a coupled physical-primary production ocean model to investigate anticyclonic eddies at two locations in the Norwegian Sea. Of particular interest are the formation of the anticyclonic eddies, and their influence on primary production.

Unique oceanographic observations - "Jotun Arctic" on survey to East Greenland fjord

During the last three years the Nansen Center has collected unique oceanographic measurements in order to quantify the subsurface fjord melting of the Greenland Ice Sheet. New data were collected in the Sermilik Fjord (SF) and adjacent East Greenland shelf in August 2010 (see map). It was proposed that a submarine melting of a glacier’ ice fronts in Greenland as well as in Antarctica is an important mechanism driving recent curving front’s retreat and glaciers acceleration.

A new insight into localisation methods in ensemble Kalman filter systems

Pavel Sakov and Laurent Bertino conducted a comparative study of two non-adaptive localisation methods popular in operational oceanographic and atmospheric data assimilation systems: covariance localisation (CL) and local analysis (LA). Both methods are applied mainly on empirical basis, and the relation between them remains largely unknown.

The authors conclude that while CL and LA are essentially different methods, in practice they normally produce essentially similar results. Apart from this main conclusion, the study contains a number of interesting theoretical advances.

Five books published in the Nansen Center's Polar series

The Nansen Centers in Bergen and St. Petersburg have published result and knowledge obtained through a wide range of joint Norwegian and Russian scientific research projects starting in 1992 with the foundation of the Nansen International Environmental and Remote Sensing Centre (NIERSC) in St. Petersburg.

Several of these books have been published through Praxis Publishers, UK (http://www.praxis-publishing.co.uk/) and their cooperation with Springer (http://www.springer.com/). These books are covering topics related to environmental, climate and remote sensing topics.

Five books published in the Nansen Center´s Polar series

The Nansen Centers in Bergen and St. Petersburg have published result and knowledge obtained through a wide range of joint Norwegian and Russian scientific research projects starting in 1992 with the foundation of the Nansen International Environmental and Remote Sensing Centre (NIERSC) in St. Petersburg.

Several of these books have been published through Praxis Publishers, UK (http://www.praxis-publishing.co.uk/) and their cooperation with Springer (http://www.springer.com/).

Advanced underwater ocean monitoring system deployed in the Fram Strait

In the EU-funded ACOBAR project (Acoustic technology for observing the interior of the Arctic Ocean) an ocean monitoring system for acoustic tomography and navigation is under deployment in the Fram Strait. The system will consist of three acoustic transceivers in a triangle and a receiver array in the middle (see upper part of the Figure - A-B-C are transceivers, D is the receiver). This system will provide acoustic travel times for model validation, assimilation and temperature inversions along 6 tracks in the Fram Strait.

Advanced underwater ocean monitoring system deployed in the Fram Strait

In the EU-funded ACOBAR project (Acoustic technology for observing the interior of the Arctic Ocean) an ocean monitoring system for acoustic tomography and navigation is under deployment in the Fram Strait. The system will consist of three acoustic transceivers in a triangle and a receiver array in the middle (see upper part of the Figure - A-B-C are transceivers, D is the receiver). This system will provide acoustic travel times for model validation, assimilation and temperature inversions along 6 tracks in the Fram Strait.