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Abstract: We study bipartite, first-order networks where the nodes take on leader or follower roles. Specifically, we let the leaders’ positions be static and assume that leaders and followers communicate via an undirected switching graph topology. This assumption is inspired by the swarming behavior of silkworm moths, where female moths intermittently release pheromones to be detected by the males. The main result presented here states that if the followers execute the linear agreement protocol, they will converge to the convex hull spanned by the leaders’ positions as long as the time-varying undirected graph defining the communication among all agents is jointly connected. The novelty of this research is that we use LaSalle’s Invariance Principle for switched systems, and additionally, the result is shown to hold for arbitrary state dimensions. [Copyright &y& Elsevier]

This paper presents a review of the state-of-the-art in understanding and quantification of the Mediterranean heat and mass (i.e. salt and water) budgets. The budgets are decomposed into a basin averaged surface component, lateral boundary components (through the Gibraltar and the Dardanelles Straits), a river input component and a content change component. An assessment of the different methods and observational products that have been used to quantify each of these components is presented. The values for the long term average of each component are also updated based on existing literature and a first estimate of heat fluxes associated with the riverine input has been produced. Special emphasis is put on the characterization of associated uncertainties and proposals for advancing current knowledge are presented for each budget component. With the present knowledge of the different components, the Mediterranean budgets can be closed within the range of uncertainty. However, the uncertainty range remains relatively high for several terms, particularly the basin averaged surface heat fluxes. Consequently, the basin averaged heat budget remains more strongly constrained by the Strait of Gibraltar heat transport than by the surface heat flux. It is worth remarking that if a short (∼few years) averaging period is used, then the heat content change must also be considered to constrain the heat budget. Concerning the water and salt fluxes, the highest uncertainties are found in the direct estimates of the Strait of Gibraltar water and salt transport. Therefore, the indirect estimate of those transports using the budget closure leads to smaller uncertainties than the estimates based on direct observations. Finally, estimates of Mediterranean heat and salt content trends are also reviewed. However, these cannot be improved through the indirect estimates due to the large temporal uncertainties associated to the surface fluxes and the fluxes through Gibraltar. The consequences of these results for estimates of the Mediterranean temperature and salinity trends obtained from numerical modelling are also considered. [ABSTRACT FROM AUTHOR]

Between 2013 and 2016 a drastic change in the vertical salinity structure in the South Adriatic Pit was recorded by Argo floats and ocean gliders. The analysis revealed that high salinity waters characterised 2013 at the surface and intermediate layers, creating the conditions for dense water formation. The year 2014 was instead marked by less saline water, dominant in the first 100 m, that spread in the entire Pit. Heat gain, negative E-P anomalies and abundant river runoff, during that period, maintained this saline stratification for more than a year. This water mass contributed to the dilution of the underlying layer, during the convection event of 2015. The spring transition period, later in 2015, as defined by new saline water placed over the winter formatted water mass and the unperturbed part of the existent salinity profile, in the deeper layers, resulted in a particular vertical structure, characterised by a double salinity maximum. High salinity waters continued to be present at the surface and intermediate layers until the end of 2016, when the strong convection led to a deep mixing, eliminating that structure. The analysis of the available datasets in the South Adriatic Pit, since 1984, linked the presence of these high salinity waters, with the cyclonic phase of the North Ionian Gyre, additionally revealing, also, years of a decreasing trend, during the anticyclonic mode of the Gyre. [ABSTRACT FROM AUTHOR]