|
|
 |
|
|
Ann. Geophys., 19, 121-129, 2001
www.ann-geophys.net/19/121/2001/
© European Geosciences Union 2001
Drifter dispersion in the Adriatic Sea: Lagrangian data and chaotic model
G. Lacorata1, E. Aurell2, and A. Vulpiani3
1Dipartimento di Fisica, Università dell’Aquila, Via Vetoio 1, I-67010 Coppito, L’Aquila, Italy, Istituto di Fisica dell’Atmosfera, CNR, Via Fosso del Cavaliere, I-00133 Roma, Italy,
and Dipartimento di Fisica, Università di Roma “La Sapienza", Piazzale Aldo Moro 5, I-00185 Roma, Italy
2Department of Mathematics, Stockholm University, S-10691 Stockholm, Sweden
3Istituto Nazionale Fisica della Materia, Unità di Roma 1 and Dipartimento di Fisica, Università di Roma “La Sapienza", Piazzale Aldo Moro 5, I-00185 Roma, Italy
Correspondence to: G. Lacorata, (Guglielmo.Lacorata@aquila.infn.it)
Abstract. We analyze characteristics
of drifter trajectories from the Adriatic Sea with recently introduced nonlinear
dynamics techniques. We discuss how in quasi-enclosed basins, relative
dispersion as a function of time, a standard analysis tool in this context, may
give a distorted picture of the dynamics. We further show that useful
information may be obtained by using two related non-asymptotic indicators, the
Finite-Scale Lyapunov Exponent (FSLE) and the Lagrangian Structure Function (LSF),
which both describe intrinsic physical properties at a given scale. We introduce
a simple chaotic model for drifter motion in this system, and show by comparison with the model that Lagrangian dispersion is mainly driven by
advection at sub-basin scales until saturation sets in.
Key words. Oceanography: General (marginal and
semi-closed seas) – Oceanography: Physical (turbulence, diffusion, and mixing
processes; upper ocean processes)
Full Article in PDF (445 KB) |
|
|
