Diurnal internal tides detected in the Adriatic

Strong diurnal oscillations, documented by temperature data that were collected along a submarine cliff on the Lastovo Island (southern Adriatic), are studied and compared with sea level and wind measurements at Dubrovnik and Komiža (island of Vis). Three thermistors were deployed at the depths of 15, 22 and 36 m between March 2001 and March 2002. Pronounced diurnal temperature oscillations were detected at 15 and 22 m during the stratified season. The correlation between the sea surface and thermocline displacements was highest in June 2001, when diurnal wind changes were not significant, while diurnal sea level oscillations achieved annual maxima. Thermocline oscillations were in phase with sea level changes. The range of diurnal sea surface variability was close to 19 cm, while the range of corresponding thermocline variability was about 5.4 m. The findings summarize the outcome of the first dedicated study of internal tides in the Adriatic

Developing a sclerochronology network in the Adriatic Sea: Growth synchrony among populations of Callista chione

Callista chone samples were live collected at three localities in the Adriatic Sea: Gulf of Venice, Italy, Pag Bay and Pašman Channel, Croatia. Acetate peel replicas were prepared and the Image Pro Primer program was used to measure increment widths in samples that had clear boundaries. Visual crossdating of the images was performed using list-year method and validated using COFECHA, while the R package dplR was used to construct the chronologies. The age of analysed shells ranged from 15 to 46 years (N = 32; 29,9 ± 8,8 years) at the Gulf of Venice, from 14 to 41 years (N = 63; 26,0 ± 5,1 years) at Pag Bay, and from 14 to 41 years (N = 33; 26,8 ± 4,8 years) at the Pašman Channel. Final statistically robust standard master chronologies spanned from 1986 to 2018 (Gulf of Venice), from 1994 to 2019 (Pag Bay) and from 1994 to 2015 (Pašman Channel). Statistically significant correlation was obtained only between the Gulf of Venice and Pag Bay residual master chronologies (1994–2018; r = 0.607; p <0.001). Although there are some coincidences between all three localities, suggesting a common signal among populations, the growth chronology in the Pašman Channel recorded a very different signal potentially linked to differing oceanographic influences. The Pašman Channel locality is more affected by the inflow of warmer and saline waters coming from the south than the two other sites which are located in geographically and hydrographically isolated Adriatic areas. No correlation was found between any shell master chronologies and surface seawater temperature. Also, no correlations between the shell C.chione master chronologies and parameters describing the Adriatic-Ionian Bimodal Oscillating System (BiOS) were observed. Correlation maps indicate different relationships between shell master chronology and chlorophyll a concentration in the region. Significant correlations were mostly limited to March and April and showed spatial variations

Aspects of the hybrid finite discrete element simulation technology in science and engineering

In this paper, the state of the art in the Combined Finite-Discrete Element Method (FDEM) has been summarized together with the fast emerging hybrid finite discrete element based simulation technology for multiphysics problems ranging from traditional engineering disciplines to biosciences and medical engineering. The key algorithmic aspects of FDEM have been summarized. The relationship between FDEM and virtual experimentation has been explained in more detail

Exceptional dense water formation on the Adriatic shelf in the winter of 2012

In this paper we document dense water formation throughout the Adriatic shelf and coastal area in January/February 2012, resulting in record-breaking densities observed during and after the event. The unprecedented dense water generation was preconditioned by a dry and warm year which resulted in a significant reduction of coastal freshwaters, superimposed on a long-term basin-wide salinity increase. The final event that triggered the dense water formation was an extended period of cold weather with strong and severe winds. Record-breaking potential density anomalies (above 30 kg m⁻³) were measured at several formation sites. Accumulated surface net heat and water losses in some coastal regions exceeded 1.5 GJ m⁻² and 250 kg m⁻² over 21 days, respectively. Excessiveness, importance of shelf-type dense water formation and effects on the thermohaline circulation and deep aquatic systems are discussed

Wintertime dynamics in the coastal northeastern Adriatic Sea: the NAdEx 2015 experiment

The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity–temperature–depth probes, glider, profiling float) and are accompanied by the atmosphere–ocean ALADIN/ROMS modelling system. The research focused on the dense-water formation (DWF), thermal changes, circulation, and water exchange between the coastal and open Adriatic. According to both observations and modelling results, dense waters are formed in the northeastern coastal Adriatic during cold bora outbreaks. However, the dense water formed in this coastal region has lower densities than the dense water formed in the open Adriatic due to lower salinities. Since the coastal area is deeper than the open Adriatic, the observations indicate (i) balanced inward–outward exchange at the deep connecting channels of denser waters coming from the open Adriatic DWF site and less-dense waters coming from the coastal region and (ii) outward flow of less-dense waters dominating in the intermediate and surface layers. The latter phenomenon was confirmed by the model, even if it significantly underestimates the currents and transports in the connecting channels. The median residence time of the coastal area is estimated to be approximately 20 days, indicating that the coastal area may be renewed relatively quickly by the open Adriatic waters. The data that were obtained represent a comprehensive marine dataset that can be used to calibrate atmospheric and oceanic numerical models and point to several interesting phenomena to be investigated in the future