Investigaton of Sea Level Change Along the Black Sea Coast From Tide Gauge and Satellite Altimetry

Abstract

ABSTRACT:In this study, we focus on sea level changes along the Black Sea coast. For this purpose, at same observation period the linear trends and the components of seasonal variations of sea level change are estimated at 12 tide gauge sites (Amasra, Igneada, Trabzon-II, Sinop, Sile, Poti, Batumi, Sevastopol, Tuapse, Varna, Bourgas, and Constantza) located along the Black Sea coast and available altimetric grid points closest to the tide gauge locations. The consistency of the results derived from both observations are investigated and interpreted. Furthermore, in order to compare the trends at the same location, it is interpolated from the trends obtained at the altimetric grid points in the defined neighbouring area with a diameter of 0.125° using a weighted average interpolation algorithm at each tide gauge site. For some tide gauges such as Sevastopol, Varna, and Bourgas, it is very likely that the trend estimates are not reliable because the time-spans overlapping the altimeter period are too short. At Sile, the long-term change for the time series of both data types do not give statistically significant linear rates. However, when the sites have long-term records, a general agreement between the satellite altimetry and tide gauge time series is observed at Poti (~20 years) and Tuapse (~18 years). On the other hand, the difference of annual phase between satellite altimetry and tide gauge results is from 1.32° to 71.48°.

Quantifying the impact of basin dynamics on the regional sea level rise in the Black Sea

“…1a. In 1993-2014, MSL was rising at a rate of 3.15 ± 0.13 mm (black dotted line) per year, in agreement with Avsar et al (2015). This value coincides well with the global MSL rise in 1992-2008 (e.g., Cazenave and Llovel, 2010).…”

“…The estimates of the BSSL rise over the 20th century, based on tide gauge records, range from 1.5 to 2.5 mm yr −1 (Boguslavsky et al, 1998;Reva, 1997;Tsimplis and Spencer, 1997;Goryachkin and Ivanov, 2006), which agrees with ∼ 1.8 mm yr −1 of the global MSL rise during the 20th century (Church et al, 2004). Based on satellite altimetry measurements during 1993-2010, the global and the Black Sea MSL then rose at a faster rate of ∼ 3.1 mm yr −1 (Church et al, 2013;Avsar et al, 2015). Both the tide gauge and altimetry records show that sea level trends in the Black Sea are not constant over time (e.g., Goryachkin and Ivanov, 2006;Kubryakov and Stanichnyi, 2013): MSL was rising at a very high rate of ∼ 28 mm yr −1 in 1993-1999 (Ducet et al, 1999;Stanev et al, 2000;Cazenave et al, 2002;Goryachkin et al, 2003;Vigo et al, 2005;Yildiz et al, 2008), and then it began to fall by ∼ 3 mm yr −1 in 1999-2007 (Ginzburg et al, 2011).…”

“…The improvement in the coastal areas of the Mediterranean Sea has recently been demonstrated by Marcos et al (2015). A reasonable agreement between tide gauge records and near-coast SLAs in the Black Sea has also been documented (Volkov and Landerer, 2015;Korotaev et al, 1998;Stanev et al, 2000Goryachkin et al, 2003;Avsar et al, 2015).…”