 |
| Titel |
Lagrangian predictability of high-resolution regional models: the special case of the Gulf of Mexico |
| VerfasserIn |
P. C. Chu, L. M. Ivanov, L. H. Kantha, T. M. Margolina, O. V. Melnichenko, Y. A. Poberezhny |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1023-5809
|
| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 11, no. 1 ; Nr. 11, no. 1 (2004-02-25), S.47-66 |
| Datensatznummer |
250009023
|
| Publikation (Nr.) |
 copernicus.org/npg-11-47-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Lagrangian prediction skill (model ability to reproduce Lagrangian drifter
trajectories) of the nowcast/forecast system developed for the Gulf of Mexico at the
University of Colorado at Boulder is examined through comparison with real drifter
observations. Model prediction error (MPE), singular values (SVs) and irreversible-skill
time (IT) are used as quantitative measures of the examination. Divergent (poloidal) and
nondivergent (toroidal) components of the circulation attractor at 50m depth are
analyzed and compared with the Lagrangian drifter buoy data using the empirical
orthogonal function (EOF) decomposition and the measures, respectively. Irregular
(probably, chaotic) dynamics of the circulation attractor reproduced by the
nowcast/forecast system is analyzed through Lyapunov dimension, global
entropies, toroidal and poloidal kinetic energies. The results allow assuming exponential
growth of prediction error on the attractor. On the other hand, the
q-th moment of MPE grows by the power law with exponent of 3q/4. The
probability density function (PDF) of MPE has a symmetrical but non-Gaussian shape
for both the short and long prediction times and for spatial scales ranging from
20km to 300km. The phenomenological model of MPE based on a diffusion-like
equation is developed. The PDF of IT is non-symmetric with a long tail stretched
towards large ITs. The power decay of the tail was faster than 2 for long
prediction times. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|