Description: For many years the Torino Cosmogeophysics group has been studying sediment cores drilled from the Gallipoli Terrace in the Gulf of Taranto (Ionian Sea) and deposited in the last millennia. The gravity core GT90-3, in which the 18O series was measured, was drilled from the Gallipoli Terrace in the Gulf of Taranto (Ionian Sea) at 39°45'53''N, 17°53'33''E. It was extracted at a depth of 178 m and its length is 3.57 m. Thanks to its geographical location, the Gallipoli Terrace is a favourable site for climatic studies based on marine sediments, because of its closeness to the volcanically active Campanian area, a region that is unique in the world for its detailed historical documentation of volcanic eruptions. Tephra layers corresponding to historical eruptions were identified along the cores, thus allowing for accurate dating and determination of the sedimentation rate. The measurements performed in different cores from the same area showed that the sedimentation rate is uniform across the whole Gallipoli Terrace. We measured the oxygen isotope composition d18O of planktonic foraminifera. These measurements provided a high-resolution 2,200-year-long record. We sampled the core using a spacing of 2.5 mm corresponding to 3.87 years. Each sample of sediment (5 g) was soaked in 5% calgon solution overnight, then treated in 10% H2O2 to remove any residual organic material. Subsequently it was washed with a distilled-water jet through a sieve with a 150 µm mesh. The fraction 〉 150 µm was kept and oven-dried at 5°C. The planktonic foraminifera Globigerinoides ruber were picked out of the samples under a microscope. For each sample, 20-30 specimens were selected from the fraction comprised between 150 µm and 300 µm. The use of a relatively large number of specimens for each sample reduces the isotopic variability of individual organisms, giving a more representative d18O value. The stable isotope measurements were performed using a VG-PRISM mass spectrometer fitted with an automated ISO-CARB preparation device. Analytical precision based on internal standards was better than 0.1 per mil. Calibration of the mass spectrometer to VPDB scale was done using NBS19 and NBS18 carbonate standards. The strategic location of the drilling area makes this record a unique tool for climate and oceanographic studies of the Central Mediterranean.

Description: The city of Venice and the surrounding lagoonal ecosystem are highly vulnerable to variations in relative sea level. In the past ∼150 years, this was characterized by an average rate of relative sea-level rise of about 2.5 mm/year resulting from the combined contributions of vertical land movement and sea-level rise. This literature review reassesses and synthesizes the progress achieved in quantification, understanding and prediction of the individual contributions to local relative sea level, with a focus on the most recent studies. Subsidence contributed to about half of the historical relative sea-level rise in Venice. The current best estimate of the average rate of sea-level rise during the observational period from 1872 to 2019 based on tide-gauge data after removal of subsidence effects is 1.23 ± 0.13 mm/year. A higher – but more uncertain – rate of sea-level rise is observed for more recent years. Between 1993 and 2019, an average change of about +2.76 ± 1.75 mm/year is estimated from tide-gauge data after removal of subsidence. Unfortunately, satellite altimetry does not provide reliable sea-level data within the Venice Lagoon. Local sea-level changes in Venice closely depend on sea-level variations in the Adriatic Sea, which in turn are linked to sea-level variations in the Mediterranean Sea. Water mass exchange through the Strait of Gibraltar and its drivers currently constitute a source of substantial uncertainty for estimating future deviations of the Mediterranean mean sea-level trend from the global-mean value. Regional atmospheric and oceanic processes will likely contribute significant interannual and interdecadal future variability in Venetian sea level with a magnitude comparable to that observed in the past. On the basis of regional projections of sea-level rise and an understanding of the local and regional processes affecting relative sea-level trends in Venice, the likely range of atmospherically corrected relative sea-level rise in Venice by 2100 ranges between 32 and 62 cm for the RCP2.6 scenario and between 58 and 110 cm for the RCP8.5 scenario, respectively. A plausible but unlikely high-end scenario linked to strong ice-sheet melting yields about 180 cm of relative sea-level rise in Venice by 2100. Projections of human-induced vertical land motions are currently not available, but historical evidence demonstrates that they have the potential to produce a significant contribution to the relative sea-level rise in Venice, exacerbating the hazard posed by climatically induced sea-level changes.

Description: Predicting the solar activity of upcoming cycles is crucial nowadays to anticipate potentially adverse space weather effects on the Earth’s environment produced by coronal transients and traveling interplanetary disturbances. The latest advances in deep learning techniques provide new paradigms to obtain effective prediction models that allow to forecast in detail the evolution of cosmogeophysical time series. Because of the underlying complexity of the dynamo mechanism in the solar interior that is at the origin of the solar cycle phenomenon, the predictions offered by state-of-the-art machine learning algorithms represent valuable tools for our understanding of the cycle progression. As a plus, Bayesian deep learning is particularly compelling thanks to recent advances in the field that provide improvements in both accuracy and uncertainty quantification compared to classical techniques. In this work, a deep learning long short-term memory model is employed to predict the complete profile of Solar Cycle 25, thus forecasting also the advent of the next solar minimum. A rigorous uncertainty estimation of the predicted sunspot number is obtained by applying a Bayesian approach. Two different model validation techniques, namely the Train-Test split and the time series k-fold cross-validation, have been implemented and compared, giving compatible results. The forecasted peak amplitude is lower than that of the preceding cycle. Solar Cycle 25 will last 10.6 ± 0.7 yr, reaching its maximum in the middle of the year 2024. The next solar minimum is predicted in 2030 and will be as deep as the previous one.

Description: his study is dedicated to the dynamics in Marine Protected Areas (MPAs) in the German Bight under different forcing scenarios. A large amount of data has been collected in the North Sea over the last decades to characterize MPAs, which can shed light on long-term changes in the North Sea dynamics from abiotic part to ecosystem. At the moment, a question is raised about the interconnection between MPAs and their representativeness for the larger area. Nowadays, this issue can be resolved with the existing numerical instruments and accumulated observations. We paid particular attention to the tidal dynamics in the North Sea since tidal residual circulation and asymmetric tidal cycles significantly define circulation patterns, transport and accumulation of biogeochemical material, and the distribution of bedforms in this relatively shallow region. We analyzed in detail the tidal energy transformation and the role of higher harmonics in the domain. The tidal ellipses, maximum tidally induced velocities, energy fluxes and residual circulation maps are constructed and analyzed. The numerical tool used in this study is the FESOM-C model (Androsov et al., 2019), which works with triangular, rectangular or mixed grids and is equipped with a wetting/drying option. A grid with a resolution of up to 10 meters in the flooded areas is used.

Description: This study is dedicated to the dynamics in Marine Protected Areas (MPAs) in the German Bight under different forcing scenarios. A large amount of data has been collected in the North Sea over the last decades to characterize MPAs, which can shed light on long-term changes in the North Sea dynamics from abiotic part to ecosystem. At the moment, a question is raised about the interconnection between MPAs and their representativeness for the larger area. Nowadays, this issue can be resolved with the existing numerical instruments and accumulated observations. We paid particular attention to the tidal dynamics in the North Sea since tidal residual circulation and asymmetric tidal cycles significantly define circulation patterns, transport and accumulation of biogeochemical material, and the distribution of bedforms in this relatively shallow region. We analyzed in detail the tidal energy transformation and the role of higher harmonics in the domain. The tidal ellipses, maximum tidally induced velocities, energy fluxes and residual circulation maps are constructed and analyzed. The numerical tool used in this study is the FESOM-C model (Androsov et al., 2019), which works with triangular, rectangular or mixed grids and is equipped with a wetting/drying option. A grid with a resolution of up to 10 meters in the flooded areas is used. Androsov, A., Fofonova, V., Kuznetsov, I., Danilov, S., Rakowsky, N., Harig, S., Brix, H., and Wiltshire, K. H.: FESOM-C v.2: coastal dynamics on hybrid unstructured meshes, Geoscientific Model Development, 12, 1009-1028, 10.5194/gmd-12-1009-2019, 2019.