EGU23-8458
https://doi.org/10.5194/egusphere-egu23-8458
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under the Creative Commons Attribution 4.0 License.
Evidence of a dual kinetic energy cascade by surface drifter observation in the Walvis Ridge Region
- 1Universität Hamburg, Institute of Oceanography, Hamburg, Germany (julia.draeger-dietel@uni-hamburg.de)
- 2Universität Bremen, MARUM—Center for Marine Environmental Sciences, Bremen, Germany
- 3Helmholtz-Center Hereon, Geesthacht, Germany
The characteristics of turbulence and processes driving it in the regime connecting mesoscales (mainly upscale energy transfer rates) and classical microscales turbulence (downscale energy transfer) are not fully well-established.
Here we analyse two-point velocity data from 2 entangled near-simultaneous relases of two different kinds of surface drifters floating in different depth (50 cm and 15 m) of the ocean mixed layer in the Walvis Ridge Region in the South Atlantik. For the 'deep drifters' the compensated third order longitudinal velocity structure function shows a positive plateau for inertial scales roughly between 15 km and 150 km,
revealing evidenve of an inverse cascade similar to former findings in the Benguela region. In contrast the 'shallow drifter'
do not show a positive platau at these scales, but show evidence of a forward cascade (negative plateau) and Kolmogorov self-similarity on spatial scale around 500 m.
How to cite: Draeger-Dietel, J., Griesel, A., Walter, M., Horstmann, J., Carrasco Alvarez, R., and Carpenter, J.: Evidence of a dual kinetic energy cascade by surface drifter observation in the Walvis Ridge Region, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8458, https://doi.org/10.5194/egusphere-egu23-8458, 2023.
