Tidligere arrangementer - Side 4
The internal waves in consideration are generated locally in combination by:
1) the North Atlantic Current (NAC) that flows along the Norwegian shelf (average speed 0.3 m/s),
2) the local tide (dominant 24 hr mode),
3) the particular shelf geometry,
4) the seasonal pycnocline (at 20 m depth). The typical amplitude is 50 m. The local depth where they exist is 100 m (approx.).
The local internal wave speed of 0.4 m/s is comparable to the current speed.
The wave generation process occurs in a sequence of:
A) locally large depressions of the internal tide occurring at the lee side of two shallow ridges,
B) the depressions are orthogonal to the current,
C) the depressions move slowly against the current, and
D) eventually fission into nonlinear-dispersive wave groups,
E) they propagate upstream against the current,
F) they are recorded on satellite images and is visible by eye.
In a recent RCN-funded project (ECOPULSE) 2020-2023 including research groups at UiO, the Norwegian Meteorological Institute and the Institute of Marine Research in Bergen, field experiments of the mother wave in points A) and C) were undertaken during July-September 2021 and 2022. The measurements show that the waves break and mix in the entire water column by convective breaking in the upper part of the water column, shear instability within the pycnocline, and by a variant of a shear instability near the bottom. The field measurements document the local wave properties and the initial phase of the fission process. The Vester?len-Lofoten area is of immense political interest because of a) its traditional fisheries and breeding ground for the North Atlantic and Barents Sea Cod and other species, where also a cold water coral reef is located right where these waves are generated. The waves do also extend across NORDLAND VII, an oil / gas field which may be considered for exploitation. Preliminary results will be presented.
Annalisa Pillepich, Max Planck Institute for Astronomy, Heidelberg
C*-algebra seminar by David Jaklitsch (University of Oslo).
by Assoc Prof Judith Reindl, Biophysics and Medical Physics, Department of Physics, UiO.
On 13 February, Dr. Brice Laurent (CSI, Mines Paris PSL) will give a guest lecture on the occasion of his visit to the TIK Centre. The lecture is open, and should be of interest to anyone in the field of Science and Technology Studies (STS).
The Departmental Seminar Series features Rosa Cordillera A. Castillo, substitute professor of public anthropology at the Institute of Anthropology and Cultural Research, University of Bremen.
Dr. Santi Roca-Fàbrega, Division of astrophysics, Department of Physics, Lund University
?pne forelesninger av Trond H. Torsvik, Sarah Johnson, Liv Hornek?r og Tue Hassenkam. Arrangementet holdes p? engelsk.
Nettverk for maskulinitetsforskning inviterer sine medlemmer til et seminar om menns vold mot menn.
Tero Aittokallio, group leader in computational systems medicine at Oslo University Hospital, will present his work "From single-cell profiling to effective drug combinations".
Department seminar. Florian Grosset is an Assistant Professor at CREST, ENSAE, Institut Polytechnique de Paris. He will present the paper "Complementarities in Labor Supply: How Joint Commuting Shapes Work Decisions" (written with Aletheia Donald).
Arkeologisk fredagsseminar med Judyta Zawalska og Kjetil Loftsgarden fra Kulturhistorisk museum, som vil presentere det p?g?ende forskningsprosjektet: "Eidsborg rock - production and trade of whetstones in the Viking Age".
Seminaret vil foreg? p? b?de norsk og engelsk.
Velkommen!
Haley De Korne discusses how a university in Mexico is including Indigenous languages and asks what we can learn from this case here in Oslo.
Hydrogels are hydrophilic polymer scaffolds surrounded by adsorbed water. From a dry state, they are capable of swelling in volume by up to two orders of magnitude – becoming up to 99% water - whilst still remaining solid (if a little squishy).
Responsive hydrogels lose this affinity for water – sometimes quite profoundly – when an environmental stimulus, such as temperature or pH, transitions beyond a critical value. Conformational changes in the scaffold squeeze the water out, and the gel shrivels dramatically. This volume change is reversible (albeit non-reciprocal), allowing for cycles of activation and deactivation. As such, responsive hydrogels have important and exciting applications in microscale actuators.
This talk will describe some of the big open areas of hydrogel modelling, before detailing two (very) recent unpublished theoretical pieces of work on 1) thermoresponsive displacement pumps for microfluidic devices, and 2) coupling pH-responsive gels to oscillating reactions to enable communication and synchronisation.
Sverker S?rlin innleder om sin nylig utgitte bok (med Eric Paglia) Stockholm and the rise of global environmental governance (CUP, 2024).
Luca Zapelli, PhD student from Department of Physics, University of Milan
by Benjamin J. W. Mills, Professor of Earth System Evolution,
School of Earth and Environment, University of Leeds, UK
QOMBINE seminar by Franz Fuchs and Ruben Bassa (UiO)
Department seminar. Annika Bacher is an Assistant Professor of Economics at BI Norwegian Business School. She will present the paper "Housing and Savings Behavior across Family Types."
Philip Roscoe (University of St Andrews) visits TIK for a seminar charting the structural, technological and social changes that gave rise to the finance we know today, and to ask how critical social scientists are to confront the likes of Elon Musk.
In this final seminar, Stine Engen will present the draft of her PhD thesis titled “On green finance and the turning of climate change into climate risk”.
Mikael Males (ILN, UiO)
Vi feirer professor emeritus Jakob Lothe med lansering av festskriftet ?Narrative Ethics: Negotiating Values?.
The first stage of sea ice formation is often grease ice, a mixture of sea water and frazil ice crystals. Over time grease ice congeals to a solid sea ice cover, often in the form of pancakes. Grease ice is usually not simulated in large-scale sea-ice ocean models, but impacts ocean heat loss and ice growth.
A set of laboratory experiments on frazil and grease ice in a turbulent flow is presented, showcasing the growth process and a frazil ice size spectrum. Existing 1D simulations illustrates how frazil ice crystals remain sub-surface and can aggregate with particles (sediments) in the water. A simple approach capturing basic grease ice properties for 3D climate models is presented and shows a 10-30% increase in mean winter Arctic Ocean heat loss compared to standard simulations. The grease ice layer is ‘hurdled’ towards existing floes and congeals as pancake ice. The onwards transition to a ‘normal’ congealed ice cover is assumed to take place over 24h when ～50 % of the grease has formed solid ice, but new observations are needed to better resolve this transition. Grease ice also dampens waves and simulating this in wave models may be the focus of future research.