TUESDAY 18th May 2021
EVENT 18:00 - 19:30 UTC+1 (Paris, Stockholm)
Water's double personality as we dive down into the supercooled state (English)
Water is the most important and abundant liquid in our planet, however, it does not behave like a normal liquid. For example, ice floats in water! Normal liquids, when becoming solid have a higher density as their molecules get closer together, and would therefore sink. This anomaly and others have been proposed to be explained by water being in reality two liquids of different density. The transition between them, as well as the critical point from which all the anomalies might be stemming from occur at very low temperatures and higher pressures. At these conditions, crystallisation happens incredibly fast, thus not previously allowing for experimental observation, but only in simulations. However, thanks to new facilities which allow ultrafast measurements with X-rays, have allowed us to see for the first time the transition between these two liquids, pointing to the existence of the critical point.
About Marjorie: Marjorie Ladd Parada is a researcher at Fysikum, at Stockholms Universitet, studying amorphous ices and supercooled (cooled below the freezing point) water using X-rays. She does not come from a Physics background, however, as her previous degrees and PhD were in Food Science. She in fact, used to study cocoa butter (yes, the fat part in you chocolate!), but this brought her to the world of X-rays, which she has found fascinating. When she is not “sciencing” she loves taking long walks, baking and reading fantasy novels.
18:30 - Online Fun Activity
Glacier-Ocean interaction in Greenlands Fjords (English)
In times of climate change, we are worried about out Ice Sheets and Glaciers, for examples around Antarctica and Greenland. With a warming ocean, the heat, transported to the Glaciers is likely to increase. We are building a Finit Element Model in order to study processes at the interface of the ocean and the glacier in a Fjord environment. Using high resolutions, we hope to get more insights on dynamics of plumes, rising along the base of the ice-shelf from the glaciers grounding line to the surface. Especially the interactions of the surrounding ocean properties (Temperature and Salinity) with the rising plume are interesting to us.
About Jonathan: My Name is Jonathan Wiskandt and I am currently a PhD Student at Stockholm University in the Department of Meteorology, studying the interaction of Ice-Sheets and the ocean in Fjords around Greenland, using a high resolution regional model. Before this, I got my Master in Kiel, Germany, at the Geomar Helmholtz Centre for Ocean Research in Climate Physics.