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Disputas: Máté Mile

Ph.d.-kandidat Máté Mile ved Institutt for geofag, Det matematisk-naturvitenskapelige fakultet, vil forsvare avhandlingen Advanced assimilation of satellite observations in a limited-area numerical weather prediction model over the Arctic region for graden Philosophiae Doctor.

Máté Mile. Foto: Privat

Máté Mile. Foto: Privat

Disputas og prøveforelesning er i Auditorium 1 i Geologibygningen. I noen tilfeller vil prøveforelesning og disputas være mulig å delta på digitalt, i så fall blir det lagt ut en lenke til Zoom.

Prøveforelesning

Fredag 22 september, 10:15-11:00, Aud 1, Geologibygningen:

Use of AI for data assimilation

Kreeringssammendrag

Satellittobservasjoner er viktige data i det globale observasjonssystemet og gir nøyaktig informasjon for værvarsling, spesielt for datasparsomme områder som Arktis. Imidlertid er bruk av satellittdata i numeriske værprediksjonsmodeller vanligvis utnyttet konservativt og ufullkomment. I denne doktoravhandlingen er det foreslått å bruke satellittobservasjoner mer konsistent i den anvendte værvarslingsmodellen, og å forbedre værvarslene ved å ta hensyn til fotavtrykket til satellittmålingen.

Hovedfunn

Populærvitenskapelig artikkel om Miles avhandling:

Advanced assimilation of satellite observations in a limited-area numerical weather prediction model over the Arctic region

Satellite observations are our best sources for observing the Earth system and provide relevant information for everyday weather predictions as well. It is clear that over the Arctic, where conventional observations are usually sparse and numerical weather prediction models are less skilful, an accurate description of the atmospheric state is not achievable without satellite observations.

Bildet kan inneholde: skråningen, font, parallell, rektangel.
Figure: The variability in the simulated satellite observations indicates areas where the footprint observation operator can better exploit the observation information for the regional atmospheric analysis and forecast. High variability can be seen near the Polar Low as indicated in the satellite image. The date of the analysis is 9 UTC, 20 March 2020. See larger figure. Credits: Satellite image: Copernicus Sentinel/2020/ESA & Variability image: Máté Mile

Therefore, data from satellites are integrated i.e., assimilated in the numerical models in order to keep the model on track with the true atmospheric state. However, the use of satellite observations is generally conservative and can include assumptions. For instance, satellite measurements point observations which assumption is not optimal for state-of-the-art numerical models.

In this doctoral thesis, a more advanced use of satellite observations is studied when the spatial extension or representation of the satellite instrument is taken into account by the so-called footprint observation operators. The study has begun with a surface type of satellite observations and progressed towards more complex footprint representations of the area which is covered in the satellite observation. It is shown that the use of the footprint observation operator for utilising satellite observation data in a numerical weather forecast model leads to better exploitation of the observations and improves short-range forecasts over the Arctic domain.

 

Foto og annen informasjon:

Pressefoto: Máté Mile, portrett; 300px. Foto: Privat

Annet bildemateriale: Figur med beskrivelse og kreditering som spesifisert i artikkelen over, størrelse 1000px.

Publisert 8. sep. 2023 10:15 - Sist endret 27. sep. 2023 13:58