title: Marine Sediments Remotely Unveil Long-Term Climatic Variability Over Northern Italy.
abstract: A deep understanding of natural decadal variability is pivotal to discuss recently observed climate trends. Paleoclimate proxies allow reconstructing natural variations before the instrumental period. Typically, regional-scale reconstructions depend on factors like dating, multi-proxy weighting and calibration, which may lead to non-robust reconstructions. Riverine records inherently integrate information about regional climate variability, partly overcoming the above mentioned limitation. The Po River provides major freshwater input to Eastern Mediterranean, as its catchment encompasses a large part of Northern Italy. Here, using historical discharge data and oceanographic measurements, we show that Po River discharge undergo robust decadal fluctuations that reach the Ionian Sea, ~1,000 km South of Po River delta, through propagating salinity anomalies. Based on this propagation, we use a high-resolution foraminiferal δ(18)O record from a sediment core in the Ionian Sea to reconstruct North Italian hydrological variability on millennial-scale for the first time. The reconstruction reveals highly significant decadal variability that persists over the last 2,000 years. Many reconstructed extremes correspond to documented catastrophic events. Our study provides the first millennial-scale reconstruction of the strength of decadal hydrological variability over Northern Italy. It paves the way to assess the persistence of large-scale circulation fingerprints on the North Italian climate.
authors.affiliation: 1] Dipartimento di Fisica, Università di Torino, Italy [2] Osservatorio Astrofisico di Torino, INAF, Pino Torinese, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Taricco
authors.affiliation: 1] Dipartimento di Fisica, Università di Torino, Italy [2] Osservatorio Astrofisico di Torino, INAF, Pino Torinese, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Alessio
authors.affiliation: Dipartimento di Fisica, Università di Torino, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Rubinetti
authors.affiliation: Università Ca' Foscari, Venezia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Zanchettin
authors.affiliation: Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS), Sgonico, Trieste, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Cosoli
authors.affiliation: Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS), Sgonico, Trieste, Italy.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Gačić
authors.affiliation: Osservatorio Astrofisico di Torino, INAF, Pino Torinese, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Mancuso
authors.affiliation: Università Ca' Foscari, Venezia, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Rubino