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PhD position in EARTH SCIENCE, FLUID-MECHANICS AND MATHEMATICS. INTERACTION AND METHODS

The National Institute of Oceanography and Applied Geophysics - OGS and the University of Trieste are issuing a call for applications to 1 PhD positions in EARTH SCIENCE, FLUID-MECHANICS AND MATHEMATICS. INTERACTION AND METHODS  (Cycle XXXVII - Academic year 2021-2022). The positions come with scholarship and will be carried out at the Division of Oceanography of the OGS. 

 

Applications close on June 7th, 2021 at 13.00 CET

More information on deadlines and admissions at https://www2.units.it/dott/en/?file=DottBandi.inc&cod=2020.
Details on the proposed research themes and contact persons for the position is below:

Project title: "Fluctuating Air-Sea Interaction in the North Adriatic Sea from Observations and Models"
Project description: Air-sea interaction is a key process in the dynamics of the atmosphere, the ocean and the climate system. Many aspects of it are today not well understood. At the air-sea interface there is an exchange of heat, inertia and chemical substances, as carbon-dioxide and other gases. The understanding of the processes are hindered by the fact that air-sea interaction involves dynamics on a large range of scales, from the molecular motion to droplet dynamics, to wave dynamics and breaking, and up to the scale of weather systems, involving a large variety of physical, chemical and even biological processes, interacting in a non-linear way. An explicit resolution of all these processes in numerical models of the dynamics is impossible, even in a far future. The important processes have thus to be parameterized in calculations of the atmosphere, ocean and climate dynamics. In the present proposal we exclusively focus on the exchange of momentum, but the formalism developed and its application can be transposed to other processes such as e.g. heat exchange.

In recent work we adapted concepts on non-equilibrium thermodynamics, where fluctuations come from thermal molecular motion, to idealized models of air-sea interaction, where fluctuations come from the turbulent motion of the fluid. We derived the Fluctuation Dissipation Relation (FDR) which connects the fluctuations of the atmosphere to the average power input to the ocean. We considered the Fluctuation Dissipation Theorem (FDT) that allows to estimate the response of a system to an external forcing by looking at the equilibrium fluctuations and Fluctuation Theorems (FT) that connects events of positive and negative events of the power-input to the ocean by atmospheric friction. More recently we showed that work relations, that is the Jarzynski equality and the Crooks relation can be applied to air-sea interaction. The FT was also investigated using data derived from satellite observations.

The purpose of the project is to further our knowledge of air-sea interaction based on the synergy of the theoretical developments performed in LEGI (Grenoble, France) and the expertise in and facilities of ocean observation of OGS (Trieste, Italy). To this end we apply the developed concepts from non-equilibrium statistical mechanics to in-situ measurements in the Gulf of Trieste. The data used are mainly surface horizontal currents  collected in the Gulf of Trieste by means of a High Frequency radar (HF-radar) positioned in Piran (Slovenia, owned by ARSO) and in Aurisina (Italy, owned by OGS). The wind data used are the output of the COSMO model.

The present project will also consider the influence of surface waves. This can be done in the Gulf of Trieste as there are two major strong wind conditions. The first is the Bora coming from land and having a short fetch and low surface waves. The second is the Sirocco coming from the south with a long fetch leading to high waves. The wave height not only increases the friction between the atmosphere and the ocean but also stores mechanical energy and transports it over large distances.
Contact person: dr. Laura Ursella lursella@inogs.it