GLOBE – Archive
E ‘being a very mild winter and rainy intensely, often severe enough to embarrass our city. And we expect hot and dry summer probably more than expected. Due to the rains that have experienced an anomaly by 86% more than the average for the period 1971-2000 at the national level this can be inferred from the data that emerge in these days. It is in fact just finished the campaign in the northern Adriatic oceanographic international ‘Carpet, Characterizing Adriatic Region Preconditioing Events’. The mission has involved researchers from the Institute of Marine Sciences of the National Research Council (ISMAR-CNR) in Venice, took place on board the research vessel Urania and the National Research Council has focused on so-called ‘dense waters’ that were formed in the North Adriatic in winter, down to the south assuming great importance in the dynamics of transport and influence the climate of the entire basin. It is in fact an effective system of renewal of coastal waters and the transport of oxygen to the deep layers. The results are of particular importance in view of the winter is characterized by mild temperatures and an exceptional rainfall, especially in the North-East of the country *.
“We observed in the Gulf of Venice, a process critical to the climate of the area,” says Sandro Carniel, scientific director of Carpet, “but also for the stability of Earth’s climate. The dynamics of dense water is in fact one of the main drivers of the global ocean circulation in the long term as it appears curious, therefore, knowledge of these processes is critical to decipher the transport of heat and salt from the Mediterranean ocean currents and therefore crucial for the planet’s climate. “
The Northern Adriatic is one of the key areas in which these processes occur. “During the winter 2013-14 this event, however, was opposed by mild temperatures and fluvial exceptional,” says Carniel. “A cruise ended, the data speak for a water temperature at the bottom of about 2 ° C higher than the average of the last 30 years. This has slowed down a lot of the ‘renewal’ of the water, that only in January-February 2012, an extremely cold winter accomplice, had instead concerned about the 60% of the volume, setting a record of absolute density measurements since I started in the Adriatic Northern (or about a century). After only two years we, so to speak, at the antipodes. ” To estimate the effects of blocking or reducing the production of winter dense water will still careful analysis of the data, using models that include atmosphere, ocean and waves. For this, the results will be disseminated and discussed Carpet dall’Ismar-CNR in an ad hoc session, during a meeting of the European Geosciences Union in Vienna, from April 27 to May 2.
“It is reasonable therefore to expect a significant impact on the movement of the waters of the basin (and the Eastern Mediterranean), the climate on the mainland and a lowering of oxygen levels on the seabed in the spring, following the phytoplankton growth stimulated by the significant riverine inputs in progress, “says Carniel. Oceanographers and engineers Carpet campaign, led by Alvise Benetazzo ISMAR-CNR, have performed measurements using cutting-edge methodologies, experimenting with autonomous underwater vehicles including, for the first time at the national level, a sophisticated ‘torpedo’, the Remus 100 ( Hydroid-Kongsberg), that captures important information about the physical characteristics of the water column, in particular on the evolution of the distribution of huge amounts of fresh water river linked to the exceptional contribution of time and the effects of the interaction between waves and currents on the seabed.
* The first month of 2014 has seen temperatures of more than two degrees (+2.1 to be exact) than the average for the reference period 1971 to 2000, ranking third among the months of January warmest since 1800 (after 1804 and 2007, with anomalies of +2.4 and +2.3, respectively). The rainfall was fairly abundant over much of the Italian territory, recording an anomaly of +86% (compared to the average of the period 1971-2000) at the national level (19 th wettest January since 1800). The most important anomalies have occurred in the northern part of the peninsula where, on average, have fallen more than two and a half times (+160%) millimeters that are usually seen in January (with a peak in the Northeast that exceed by more than four times the average rainfall in those areas), by closing the month to Northern Italy as the third wettest ever: from 1845 was not seen in similar anomaly in Northern Italy. (Source: ISAC-CNR, Michele Brunetti)
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