Oscar Martínez-Alvarado
Current Research
- Forecast error
- Diabatic processes in extratropical cyclones (as part of the DIAMET Consortium Project)
Past Research
- Low-order behaviour in the Martian atmosphere
- Planet-encircling Martian dust storms
- Nonlinear dynamics in a dripping faucet
- Turbulence in lakes
- Other stuff
Sting jets
Related Links
- Publications
- Project page (Mesoscale group)
Low-order dynamical behaviour in the Martian atmosphere
Many observational and numerical studies have shown that the Martian atmosphere is more regular than our own atmosphere. This have led to the hypothesis that the Martian climate attractor can be a low-dimensional attractor suitable to be described to a given significant level of accuracy by a finite (and small) number of modes. There are many possible choices to establish these modes. One possibility is the use of total energy-based empirical orthogonal functions (EOFs), obtained by means of a proper orthogonal decomposition (POD). We have developed a method to establish a relationship between EOFs and wave motions such as thermal tides and transient waves, known to be important for the atmospheric general circulation of the planet.
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Planet-encircling Martian dust storms
A rather interesting characteristic of the Martian atmosphere not yet fully understood is its capacity to develop and sustain planet-encircling dust storms. I am interested in how the general circulation is affected during the initial stages of the development of a storm. In particular, I have looked at the chages suffered by the thermal tides while the storms starts developing as a regional dust storm.
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Nonlinear dynamics in a dripping faucet
A dripping faucet with a constant liquid supply is a classic example of a system exhibiting a whole range of dynamic behaviour ranging from regular and periodic to chaos.
My work with a dripping faucet consisted of numerical simulations with two different models, on the one hand, a very accurate model based on the solution of the equations of motion starting from the construction of an appropriate Lagrangian (Fuchikami et al., 1999), and on the other hand, a reduced-model based on an EOF-Galerkin projection (Coullet et al., 2000). Furthermore, I removed the constant water supply and put a time-dependent one instead. This lead to an even richer behaviour with new regimes such as synchronisation, Arnol'd tongues, and chaos control.
References
- N. Fuchikami, S. Ishioka, and K. Kiyono, J. Phys. Soc. Jpn. 68, 1185 (1999)
- P. Coullet, L. Mahadevan, and C. Riera, Prog. Theor. Phys. Suppl. 139, 507 (2000)
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Turbulence in lakes
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Other stuff
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