Norsk tekst

Lars H. Smedsrud

Professor,  Geophysical Institute,
University of Bergen


part of the Bjerknes Centre for Climate Research




Lars H. Smedsrud has a wide experience in polar oceanography from Arctic and Antarctic waters.
Smedsrud leads a network for polar researchers at the University in Bergen and is a professor II at the University Centre in Svalbard (UNIS).
He is the US-Norway Arctic Fulbright Chair 2019-2020, member of the Scientific Steering Group in CliC (Climate and the Cryosphere) from the  World Climate Research Programme, and is one of the coordinators in Arctic ECRA (European Climate Research Alliance).

In March 2000 Smedsrud accomplised his PhD on frazil ice formation and sediment entrainment in polar waters, and has worked with projects related to sea ice formation in the Arctic and melting of ice-shelves in Antarctica since then. Smedsrud has extensive field experience, has been cruise leader during the International Polar Year, participated in several international laboratory experiments, and worked with a number of numerical models. Modelling activity includes vertical column modelling of the Arctic Ocean and sea ice cover, sub ice shelf circulation under the Fimbul Ice Shelf in Antarctica, polynya dynamics on Svalbard, and melting and export of sea ice in Global Earth System Models.


Research areas:


Variability in the Arctic Ocean and Nordic Seas; 
Natural climate variability appears especially large in the Atlantic sector of the Arctic outside the coast of Norway, including the Greenland and Barents Seas. A number of studies now confirm this, and one of the most central ones is perhaps the synthesis that was written about the Barents Sea (Smedsrud et al., 2013). Large natural climate variability in the air-ice-ocean system was documented over the last 2500 years. In any regard is it clear that the last decades have been warmer than "normal" and had less winter sea ice cover than "normal" - direct evidence of ongoing global climate warming.   
Large variations have also been documented in the southward export of sea ice area between Svalbard and Greenland (Smedsrud et al., 2017). How large the influence of the large increase in ice-area export is on the Arctic sea ice loss as a whole is still under debate. This is also true for the overall effect of ocean heat transport. However, a direct effect between ocean heat transport and the Barents Sea ice has been found (Årthun et al., 2012) and also in the area north of Svalbard (Onarheim et al., 2014), but the over-all influence is still under debate. In any regard is there now signficant loss of sea ice in all the Arctic seas, but it varies from sea to sea for what time of the year this loss is most prevalent (Onarheim et al., 2018).


Melting of the Antarctic ice sheet;
The Fimbul Ice Shelf - Top to Bottom - has over the last years tried to estimate the overall mass balance of the largest ice shelf along Queen Maud Land in Antarctica. This floating part of the Antarctic ice sheat is special because it is overhanging the continental slope. Outside the Fimbul ice shelf relatively warm water resides, and the water warmed significantly from the 1970's to 2001 as described in a paper in Deep Sea Research. The warm water enters into the cavity, governing the melting of the ice shelf. A numerical study showing temperature fields and currents is published in Journal of Geophysical Reserach, but new data now suggest that the model needs modifications. At the surface new sea ice formation takes place, and this leads to salt rejection which makes the water dense enough to sink down along the slope, and renew the bottom water of the world oceans. A study of the downflow of this dense water on the Weddell continental shelf is published in Tellus.

Modeling the Arctic Ice Cover; A coupled air-ice-ocean culumn model has been very useful in a number of studies. The important processes are included, and results indicate that the sea ice export is a stronger driver of thinning for the ice than the estimated increased oceanic heat transport. Heat transport in the atmosphere have remained on the same level as around 1990 and cannot explain the recent ice loss.  Satellitte images show that the ice export has increased steadily since 2004, and a paper in The Cryosphere has all the details. If the ice export remains as high as presently  the Arctic ice-cover will remain close to the present level. But, if the export decrease to the previous lower level, the Arctic ice-cover could recover significantly. On longer timescales increase in radiation due to increased green house gases leads to a 95 % open water situation during summer 2050 (a 2*CO2 scenario). First results were descibed in a Geophysical Research Lettersand these were sort of confirmed in a new study in Ocean Modelling.

Sea ice formation in open water; I study how the first ice formation depend on the surrounding forcing, mostly the wind speed creating turbulence in the ocean, snow drift and high heatfluxes to the cold air above. If the first ice cover becomes a thin layer of solid ice rather than a layer of slush, heat fluxes will be an order of magnitude lower, and less salt will be released to the ocean below. The first field work in Polar Ocean Climate Processes took place in March 2003 in Svea. The next three field seasons were spent at a cabin on Edge Øya in Storfjorden. Scientific results may be found in a Cold Regions Science and Technology article. When sea water freezes and the water is sufficiently turbulent from wind or tides, frazil ice formation will be the result. These crystals look much like snow flakes, and are diffused down into the water. They contribute to a more efficient ice formation and thereby also a higher salt flux then during normal congelation ice growth. Frazil ice forms in rivers, in leads or polynyas, and below Antarctic ice shelves. Image of congealed frazil ice.



Publications  (abstracts & full text PDF's) 
Curriculum Vitae (CV)
Talks & Posters
Media & popular science

Active projects
ice2ice (Arctic Sea Ice and Greenland Ice Sheet Sensitivity)
MOSAiC
BASIC (Boundary layers in the Arctic atmosphere, Seas and Ice dynamics)
Nansen Legacy
INTAROS (Integrated Arctic Observing System)


Supervsion and teaching

Supervsion of PhD students: Marius Årthun (22.09.2011), Sara de la Rosa (30.09.2011), Marta Zygmuntowska (11.06.2014),
Aleksi Nummelin (28.10.2016), Ingrid Onarheim (7.12.2017), 
Jonathan W. Rheinlender and Morven Muilwijk.
Supervision of Master students:  Ingrid Onarheim (June 2013), Océane Richet August 2013),
Natasha Ridenour +
Mari Halvorsen (June 2014), Martin Arntsen (UNIS, June 2015), Morven Muilwijk (June 2016),
Philipp Anhaus (December 2017) and Alex Hamel (UCSD, May 2020).

Teaching:

Data analysis in Oceanography og Meteorology
(GEOF210, autumn 2007 and 2013),
Polar Oceanography (GEOF338, spring 2013, 2014, 2015, 2016),
Physics of the Atmosphere and Ocean (GEOF105, autumn 2014, 2015, 2016)
Air-Ice-Sea Interaction II (UNIS, AGF311, November 2016) 
Sustainable Arctic Energy Exploration and Development (UNIS, AGF353, summer 2017, 2019)

Activity
Polar Sciences Network in Bergen
Advisor: EU-PolarNet, Ice911.org

Previous projects and activity
N-ICE 2015 (Norwegian young sea ICE cruise 2015)
Coordinator of the Atmosphere, cryosphere, ocean processes BCCR (2013 - 2017).  webblogg for RG5@BCCR
Bergen Ice Group and related fieldwork
Fimbul Ice Shelf - Top to Bottom
Bipolar Atlantic Thermohaline Circulation (BIAC)
Dynawarm (Dynamics of past warm climates)
NorClim
Polar Climate and Heat Transport (Pocahontas)
REduced ice Cover in the ARctic Ocean (RECARO)
Polar Ocean Climate Processes (ProClim)
Transport Programme

Previous administrative duties;
Forum for Research into Ice Shelf Processes (FRISP)    www pages and editor of reports 2002-2007
Norwegian Ocean and Climate Project, NOClim  and  Polar Ocean Climate Processes, ProClim   www pages, and outreach


Photoalbum


Adress

Lars Henrik Smedsrud
Geophysical Institute 
Allégaten 70, 5007 Bergen, Norway 

Office: West Wing, Geophysical Institute. 
Second floor, Room 2220. 

Phone: +47 55 58 26 38  
Twitter: @islarsh
Email:
Lars.Smedsrud@uib.no
Web: http://www.uib.no/en/persons/Lars.Henrik.Smedsrud



ORCID iD iconorcid.org/0000-0001-7391-0740