TRR 181 Seminar "Mesoscale and high frequency variability in the Denmark Strait Overflow"

The TRR 181 seminar is held byStylianos Kritsotalakis (AWI, PhD in T3),on November 28, 11 am at Universität Bremen,room NW1, U1050 (Otto-Hahn Allee 1).

Abstract

"Past observations of the Denmark Strait Overflow (DS0) plume indicate energetic mesoscale variability on timescales of 2-10 days. Additionally, in the region downstream of the Denmark Strait Sill (DSS), previous studies have inferred that mesoscale features can induce mixing between the DSO plume and the ambient waters (Voet et al., 2010 and Schaffer et al., 2016). During August 2018 a square-shaped mooring array experiment, along with repeat hydrographic sections, was carried 120km downstream of the Denmark Strait Sill DSS (on the continental slope of Greenland). The array allowed for velocity and temperature measurements to be conducted up to 300m above the local bathymetry of each mooring for approximately 12 days. Dense (σ_θ > 27.8 kg m^-3) and cold (Θ < 2^oC) waters that characterize the DSO plume were detected at all moorings simultaneously while the dominant scale of variability was 1.6 days and was associated with mesoscale activity. Specifically, we find that this mesoscale field consists of cyclonic (CCW) and anti-cyclonic (CW) eddies, with the center of the anti-cyclones being predominantly located more upslope than the center of the cyclones. These results are in good agreement with the model study of Jungclaus et al., 2001. Furthermore, wavelet spectrum analysis of the velocity field reveals, at various times, the concurrent existence of high energy in scales ranging from the mesoscale up to the turbulent regime. "