Lagrangian properties of eddy fields in the northern North Atlantic as deduced from satellite-tracked buoys

• Published in: Journal of Marine Research
• Main Authors: Krauß, Wolfgang, Böning, Claus W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sears Foundation of Marine Research 1987
• Subjects: Newfoundland; north atlantic current; North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/6795/; https://oceanrep.geomar.de/id/eprint/6795/1/s1.pdf; https://doi.org/10.1357/002224087788401142

One hundred and thirteen satellite-tracked buoys have been used during their first 5 months after deployment in order to calculate Lagrangian statistics of the eddy field in the northern North Atlantic between Newfoundland and the Canary basin. r.m.s. velocities are isotropic and increase from southeast to northwest. Lagrangian integral time scales, derived both from correlation function and from dispersion, are slightly anisotropic and decrease from the subtropics toward the North Atlantic Current. Time scale is inversely proportional to the r.m.s. velocity of the eddies. Eddy length scale is approximately constant in the North Atlantic. Dispersion is in good agreement with Taylor's hypothesis, following a t2-law during the first day after release and a linear increase with time during days 10 to 60. Eddy diffusivity increases from 30N to 50N by a factor of about 4 and is linearly dependent on the r.m.s. velocity. The energy containing frequency band of the eddies shifts toward higher frequencies in the northern part of the Atlantic. Beyond the cut-off frequency of the eddies the spectral slope follows a -2 or -3 power law.