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TIDAL VARIATIONS OF SEA LEVEL AT VARNA TIDE GAUGE
Abstract
Sea level change and global sea level rise are slow but persistent changes. They should be evaluated as a sign of ongoing climate changes. The Black Sea is a semi-enclosed sea, with the only connection to the world's oceans being the narrow Bosphorus Strait. The influence of climate changes in such an environment will be grater. Sea level observations on the Bulgarian part of the Black Sea are carried out by numerous tide gauge stations. The most indicative of them, with the most complete set of measurements, is the Varna tide gauge station. The series of observations spread to a period of over 95 years (1928-2025). The sea level data from tide gauge station is corrected for the Earth vertical movements at the site. The objective of the analysis is to determine long-term tidal influences and establish the mean sea level and its changes. Monthly sea level data are available for this time interval. The data series were analyzed using a least squares linear regression model includes decadal, annual, semiannual variations of sea level, trend and mean sea level. The mean sea level was determined and a sea level trend of about 1.3mm per year has been established. Hourly sea level data is available since May 2013. Roughly 90,000 hourly values are available for the observation period 5.2013-12.2024. The period of observations considered is sufficient to establish the influence of the annual and semi-annual tides, as well as to distinguish between multiple daily and semi-daily tides. The purpose of the analysis is to determine the influence of long-period and short-period tides. The least squares harmonic analysis was used in the analysis of hourly sea level values. The harmonic analysis was used to solve the amplitudes and phases of the long and short term tidal constituents. The influences of nearly seventy statistically significant short-term tidal have been identified. The results obtained from the harmonic analysis from hourly data for the annual and semi-annual tides were compared with those from the linear regression model -monthly data.
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References10
Bondar, C. (2007). The Black Sea level variations and the river-sea interactions. GEO-ECO-MARINA 13/2007, 43�50.
Medvedev, I.P., (2024). Variance of Short-Period Sea Level Oscillations in the Black Sea: Seasonal and Interannual Variations. Physical Oceanography, 31(1), pp. 59-70
Ivanov A,, N. Dimitrov. Chronological changes in the Black Sea level at tide gauge station Varna 1928-2023. Engineering Geology and Hydrogeology, 38, Geological Institute, Bulgarian Academy of Sciences, 2024, ISSN:0204-7934, DOI: 10.52321/igh.38.1.81, 81-88.
Genov, I., Slavova, K., Koleva-Rekalova, E., Dogan, T. 2024. Events and data concerning the Black Sea evolution after the last glacial peak: A comment. GeologicaBalcanica53 (2), 11�28, DOI: 10.52321/GeolBalc.53.2.11
Golyandina, N., Osipov, E. The �Caterpillar�-SSA method for analysis of time series with missing values. Journal of Statistical Planning and Inference 13. 2007, pp2642 � 2653p. DOI: 10.1016/j.jspi.2006.05.014
Codiga, D.L., Unified Tidal Analysis and Prediction Using the UTide Matlab Functions, Technical Report 2011-01, Graduate School of Oceanography, University of Rhode Island, Narragansett, RI., USA, 2011, 59pp.
Thompson, K. R., An analysis of British monthly mean sea level, International Scientific Event, Geophys Journal, Royal astronomical. society. vol 63, 1980, pp57-73. DOI: 10.1111/j.1365-246x.1980.tb02610.x
Ivanov A., Georgiev I., Dimitrov N. (2019). Analysis of 90 years sea level data at Varna tide gauge station. 19th International Multidisciplinary Scientific GeoConference SGEM 2019. 9.Geodesy and Mine Surveying. Book 2.2. pp11-16, ISSN 1314-2704, DOI: 10.5593/sgem2019/2.2/S09.002.
Ivanov, A. Harmonical analysis of sea level data at Varna tide gauge. Proceedings of 23rd International Multidisciplinary Scientific Geo Conference SGEM 2023, 23, 2.1, International Multidisciplinary Scientific GeoConference, 2023, ISBN:978-619-7603-57-6, ISSN:1314-2704, DOI: 10.5593/sgem2023/2.1/s09.26.
Church J.A. White N.J., Coleman R., Lambeck K. and Mitrovica, J.X. ( 2004) Estimates of the regional distribution of sea - level rise over the 1950 to 2000 period. Journal of Climate 17, 2609 � 25. DOI: 10.1175/1520-0442(2004)017<2609:eotrdo>2.0.co;2
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