ESP GUEST SEMINAR - MONDAY 22 MAY - 11:00 - Davide Faranda - Common Area - SISSA building 2nd floor, via Beirut

[Henningsen Susanne]

ESP GUEST SEMINAR

Monday, 22 May 23 at 11:00
SISSA common area and on zoom

*Davide Faranda
*

*Learning a weather dictionary of atmospheric patterns using Latent 
Dirichlet Allocation to study climate change & extreme events*

Mid-latitude circulation dynamics is often described in terms of weather 
regimes. Each pattern is given by a given combination of several 
synoptic objects (cyclones and anticyclones). Such intrication makes it 
arduous to  quantify recurrence and intensity of climate extremes. Here 
we apply Latent Dirichlet Allocation (LDA), used for topic modeling in 
linguistic, to build a weather dictionary: we define daily maps of a 
gridded target observable as documents, and the grid-points composing 
the map as words. LDA provides a representation of documents in terms of 
a combination of spatial patterns named motifs, which are latent 
patterns inferred from the set of snapshots. For atmospheric data, we 
find that motifs correspond to pure synoptic objects (cyclones and 
anticyclones), that can be seen as building blocks of weather regimes. 
We show that LDA weights provide a natural way to characterize the 
climate change for the recurrence of regimes associated with extreme events.


https://zoom.us/j/98180870364
ID      981 8087 0364
Psw 241357

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Earth System Physics
ICTP, Trieste, Italy