What happens with the Ekman current under constant wind?
- 1School of Computing and Mathematics, Keele University, Newcastle under Lyme, United Kingdom of Great Britain – England, Scotland, Wales (v.i.shrira@keele.ac.uk)
- 2Department of Mathematics, Faculty of Science, Misurata University, Misurata, Libya
The work examines the Ekman current response to a steady
wind within the Stokes-Ekman paradigm. Under constant wind
in the classical Ekman model there is a single attractor
corresponding to the Ekman (1905)steady solution. It is
known that the account of wind waves strongly affects the
Ekman current dynamics via the Stokes drift, which is
described by the Stokes-Ekman model. Waves continue to
evolve even under constant wind, which makes steady
solutions of the Stokes-Ekman equation impossible. Since
the dynamics of the Ekman response in the presence of
evolving wave field have not been considered, the basic
questions on how the Ekman current evolves and,
especially, whether it grows or decays at large times,
remain open.
Here by employing the known self-similar laws of wave
field evolution and solving analytically the
the Stokes-Ekman equation we find and analyse
evolution of the Ekman current. We show that the system has
a single time dependent attractor which can be described
asymptotically. The large time asymptotics of the Ekman
current is found to be determined by the regime of wave
field evolution: for the regimes typical of young waves
the Ekman current grows with time to infinity, in contrast, for
`old waves' the Ekman current asymptotically decays.
How to cite: Shrira, V. and Almelah, R.: What happens with the Ekman current under constant wind?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-588, https://doi.org/10.5194/egusphere-egu21-588, 2021.