3 papers
physics.ao-ph2026
Koopman Analysis of Sea Surface Temperature with a Signature Kernel
Nozomi Sugiura, Satoshi Osafune, Shinya Kouketsu
We develop a trajectory-based Koopman method for sea surface temperature (SST) that lifts annual SST segments using a signature kernel -- a reproducing kernel Hilbert space (RKHS)…
physics.ao-ph2021
Simple El Niño prediction scheme using the signature of climate time series
Nozomi Sugiura, Shinya Kouketsu
El Niño is a typical example of a coupled atmosphere--ocean phenomenon, but it is unclear whether it can be described quantitatively by a correlation between relevant climate event…
physics.geo-ph2019
Estimating the population mean for a vertical profile of energy dissipation rate
Nozomi Sugiura, Shinya Kouketsu, Shuhei Masuda +2
Energy dissipation rates are an important characteristic of turbulence; however, their magnitude in observational profiles can be incorrectly determined owing to their irregular ap…