image of me

 Lars H. Smedsrud
 Researcher in oceanography,  Bjerknes Centre for Climate Research

 

Norsk tekst

Geophysical Institute


Research areas:

Melting of the Antarctic ice sheet; Im working on a project set to estimate the mass balance of the Fimbul ice shelf (Fimbul Ice Shelf - Top to Bottom) - 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; I started using a simple yet physical model of the Arctic ice-cover in 2007. 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. If this 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). More details on these results may be found in a Geophysical Research Letter.

Sea ice formation in leads and polynyas on Svalbard; 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. If you have a good internet connection (> 1 Mbit/s) and Windows Media Player, you may watch a film from the fieldwork: "When the ice comes". Scientific results may be found in a Cold Regions Science and Technology article.


Incorporation of sediment into sea ice in the Kara Sea;
This was the work of my PhD, and the project was motivated by the fact that different types of pollution enters the Arctic Ocean through the rivers Ob og Yenisey. Many pollutants adheres to sediment, and if the sediment is incorporated into sea ice, the pollutants will be advected along with the ice and out into the North Atlantic or the Barents Sea. The Norwegian Polar Institute has had different related projects over a number of years, most recently the Transport Programme. Picture of sediment on ice in the Barents Sea

Frazil ice formation; 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

Active projects
Fimbul Ice Shelf - Top to Bottom
Bipolar Atlantic Thermohaline Circulation (BIAC)
NorClim
Polar Climate and Heat Transport (Pocahontas)
REduced ice Cover in the ARctic Ocean (RECARO)

Activity
Fieldwork
Ocean-ice-atmosphere Processes (Bjerknes Research Group 3)
Bergen Polar Ice Group
KV Svalbard cruise March 2007

Previous proposals
Arctic Ice Cover Sensitivity
Bergen Polar Ice Group

Previous projects
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
Office: Østfløyen 206 
Geophysical Institute 
Allégaten 70, 5007 Bergen, Norway 

Phone: +47 55 58 26 38 
Fax:     +47 55 58 98 83 
Email: larsh@gfi.uib.no
Web: www.uib.no/People/ngfls