Metrological Analysis of Geopotential Gravity Field for Harbor Waterside Management and Water Quality Control

Sea level oscillations are the superposition of many contributions. In particular, tide is a sea level up-down water motion basically depending on three different phenomena: the Earth-Moon-Sun gravitational relationship, the water surface fluid reaction to atmospheric meteorological dynamic, and the Newtonian vertical adjustment of the sea surface due to atmospheric pressure variations. The first tide component (astrotide) is periodic and well known in all points of the Earth surface; the second one is directly related to the meteorological phenomenon, and then it is foreseeable; the Newtonian component, on the contrary, is not readily predictable by a general hydrostatic law, because the factor that represents the Newtonian transfer (from the atmospheric weight to the consequent sea level) is variable in each harbor area. The analysis of the gravity field permits to forecast the sea level variation due to meteorological tide events, and its metrological analysis highlights a compensation in the inverse hydrobarometric factor to be taken into account to correctly compensate atmospheric pressure variations in semibinding basins. This phenomenon has several consequences in Harbor Waterside management and in water quality control as shown by the reported case studies and introduces a new reference parameter: the so-called Water 1000. “Dedicated to the memory of Ilaria Sanvenero” The topic of this article should have been part of a degree thesis by Ilaria, a brilliant physics student at the University of Pisa. She left us at the age of twenty-two. Here, we wish to remember Ilaria by paying public homage to her brief but precious work. 1. Introduction During the last three years, the metrological observation of tide waves highlighted a phenomenon of seawater level fluctuations in port/coastal basins, strictly connected to Climate Global Change (CGC), caused by weight variations of the above atmosphere district (gravity field variations) that produce a Newtonian compensation by sea level imbalance also two time greaters than the one produced by astronomical tides; moreover, the time duration range of these phenomena is 24–120？h. This phenomenon is the first measured example, not extraordinary, of the direct effect of CGC on human life: in fact, metrological observations pointed out a constant increment of amplitude variation and pressure with a consequential anomalous seawater level variation in port basins (superhigh and superlow tides) with several consequences on human activities. The phenomenon has also significant effects on the quality of port waters.