Séminaires

Atmosphere-ocean interactions in the Adriatic basin at different scales: cold air outbreaks, storm surges and meteotsunamis
Matjaz Licer (NIB, Slovenia)

B6d R22 (0/22), Chimie Travaux Pratiques
Bâtiment B6d, Quartier Agora, Allée du 6 Août, 7, B-4000 Liège 1 (Sart-Tilman)

Adriatic sea is a NW-SE oriented elongated semi-enclosed basin in the Northern Central Mediterranean, communicating with the Ionian Sea through the Otranto strait in the south. It is about 800 km long and 200 km wide and surrounded from all sides with mountain ridges, which exert significant influence on the basin dynamics through topographic control of the air-flow. Topographic control plays a role during the two dominant wind forcing regimes: cold northeasterly bora and warm southeasterly sirocco wind. We will take a bird's eye view at several examples of extreme air-sea interactions in the basin. Hurricane bora wind event from February 2012 will be presented, along with the related turbulent air-sea fluxes, circulation and consequent dense water formation on the shelf. We show the role of two-way atmosphere-ocean feedback during numerical modelling of these transient events. Sirocco wind, on the other hand, is the leading factor causing Adriatic storm surges, which cause coastal erosion and flooding of northern coastal towns like Venice and Piran. We will discuss why Adriatic storm surges are easy to understand but difficult to forecast, and how this problem can be tackled through numerical ensemble modelling. Finally, the physics of meteotsunamis, i.e. tsunamis of meteorological origin, will be discussed. These are strong harbor seiches in the tsunami frequency band, induced by high frequency air pressure modulations due to travelling atmospheric disturbances. They are quite frequent (several event per year) in the Mediterranean and Adriatic and can cause severe damage. We will revisit historic meteotsunami occurrences in the Adriatic and make a quick digression to show some propagation and amplification properties of these waves over the Balearic archipelago (Spain).

Sorting out CP symmetries in a basis-invariant way
Igor Ivanov (CFTP, Instituto Superior Técnico, Lisbon)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)

The quest for the origin of CP violation leads many to build and explore multi-Higgs models, in which is arises naturally. But one first needs to understand what is actually broken in CP violation. Surprisingly, there can exist exotic forms of CP symmetry, which are physically distinct from the usual CP, and multi-Higgs models realizing them started to appear only very recently. I will explain how to recognize the hidden presence of such CP symmetries and their breaking in basis-invariant way.

Probing high-mass star formation: An observational perspective
Anandmayee Tej (Indian Institute of Space Science and Technology, Trivandrum, INDIA)

Centre Spatial de Liège
Bâtiment B29, Liège Science Park, Avenue du Pré-Aily, B-4031 Angleur

Massive stars play a vital role across the universe given their radiative, mechanical and chemical feedback. They dictate the energy budget of the galaxies through enormous radiation, powerful winds and supernovae events. However, most aspects of the processes involved in their formation are far less understood in contrast to the low-mass regime. In this talk I will dwell upon observational manifestations of the interaction of the massive stars with the surrounding interstellar medium at various evolutionary stages and emphasize on the role of multiwavelength observations in understanding high-mass star, their formation and feedback on the surrounding medium.

I will spend a few minutes towards the end of the talk in discussing about my institute which is the academic cradle of the Indian Space research Organization.

TBA
Agnès Kospal (Konkoly Observatory)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)


Café, thé et biscuits seront servis après le séminaire...