GEODETIC STUDIES OF THE INFLUENCE OF CLIMATE CHANGE ON THE BLACK SEA LEVEL TREND

In this paper the problem for establishing the Black sea level trend related to the global climate change is discussed. It is well known that the mean sea level is a close approximation of the geopotential surface geoid (vertical datum), which is the true zero surface for measuring physical elevations. Definition characteristics of geoid surface are considered in two aspects (geometrical and gravimetric model) in accordance with the high accuracy and temporal-spatial resolution of modern geodetic measuring techniques. The possibility of 'absolute' sea level change determination using Global Navigation Satellite System (GNSS) stations collocated to the tide gauges, precise levelling and gravimetric measurements of geodetic points to connect independent geodetic systems to a one world reference system are considered. The geodetic measurements in the Black sea region will contribute to the complex studies of the World Ocean and open seas, and to find out the correlations between trend estimates obtained from different type of data. Long-term sea level changes are statistically significant and it is a matter of future more precise determination of their values. For that purpose it is needed a comprehensive, interdisciplinary research in terms of incorporating ancillary data types and various geophysical models as well.