Thermohaline staircase formations in the Tyrrhenian Sea

What determines the thickness of layers in a thermohaline staircase?

“…Such a slow predicted evolution of thermohaline staircases by merger is supported by some of the oceanographic observations -see, for example, figure 11(a, b) in Zodiatis & Gasparini (1996) for the Tyrrhenian staircase. The equilibration of a staircase in the analytical theory ( § § 2,3) was attributed to the fact that interfacial density ratios approach a critical value R min , where ∂γ /∂R changes sign.…”

“…The anticorrelation of the step heights withR is particularly conspicuous for layers within the same staircase (see, for example, table 1 in Zodiatis & Gasparini 1996) but can also be noticed by comparing the different staircases (Schmitt 1981). The strikingly uniform apparent flux convergence ratio noted by Schmitt et al (1987) may also be directly related to the predicted uniformity of γ in the fully equilibrated staircases.…”

Long-term monitoring programme of the hydrological variability in the Mediterranean Sea: a first overview of the HYDROCHANGES network

“…They have a similar variability of about 0.03 • C with the deeper one being about 0.05 • C cooler than the shallower one. The frequent sudden θ jumps are a striking feature that might be indicative of internal waves passing by and displacing the interfaces of the thermohaline staircases, which are typical for the deep central Tyrrhenian subbasin (stairs of 20-54 m thickness, separated by thinner interfaces of about 2-27 m, as reported by Zodiatis and Gasparini, 1996). The time series is still too short for any further analysis of longterm processes.…”

“…The deep mooring in the southern Tyrrhenian (Fig. 9) is placed in a relevant site to be monitored for a number of peculiar characteristics: it has relatively weak dynamics (Vetrano et al, 2010), making it a suitable site to monitor the long term evolution of hydrographic properties of deep water masses (Gasparini et al, 2005); it has a highly oligotrophic regime and appears to have been a net CO 2 source for the atmosphere from the 1960s to the 1980s and only transformed into a sink in the 1990s (Louanchi et al, 2009); it is a salt fingering region characterized by the presence of thermohaline staircases in the deep layers (Zodiatis and Gasparini, 1996), subject to internal waves which modify the vertical fluxes. Two θ time series are shown in Fig.…”

Characteristics of Thermal Finestructure in the Southern Yellow Sea and the East China Sea from Airborne Expendable Bathythermograph Measurements

“…(1) staircase, also called steppy or stepwise structure (Schmitt et al, 1987;Zodiatis and Gasparini, 1996), when temperature and salinity profiles show alternative sheets (strong temperature/salinity gradient in short vertical distance such as d 1 to d 2 (~1 m) or d 3 to d 4 (~2 m) in Fig. 1(a)) and layers (almost isothermal/isohaline or low gra- (Georgi, 1978(Georgi, , 1981Toole, 1981), the Atlantic (Joyce, 1976;Schmitt and Georgi, 1982;Schmitt et al, 1986), and the Pacific (Gregg, 1977;Peters et al, 1991).…”