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  • Metocean report; extreme minimum water temperatures (26-08-2016)

Metocean report; extreme minimum water temperatures (26-08-2016)

    WOZ_RVO.nl
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    Asked by WOZ_RVO.nl 450 days ago Answers (1)

    The Metocean report clearly describes and illustrates the extreme high water temperature. What is to be considered  for the extreme minimum water temperature?

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      • WOZ_RVO.nl
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        WOZ_RVO.nl 450 days ago

        No analysis on extreme minimum water temperature has been conducted for Borssele. The following can be considered as input: In general the freezing point of saline water is ~ −2 °C with typical values of salinity ~30 ppt. However, due to the influence of the relative warm Gulf Stream and therefore the relative mild North Sea climate the minimum temperature of the sea water surface near BWFZ will be several degrees above ~ −2 °C. Following Figure 8.2 of the BWFZ Metocean reports this is confirmed showing that the water temperature does not drop below +2°C. The applied hindcast dataset (CFSR) provides similar values; minimum values above 2°C during the period between 1979 – 2010. When analysing measurement records of the coldest winters in the Netherlands, available for the period 1907 – 2010 it is noted that the years 1963, 1979, 1985, 1996 and 2010 (for which these last four winters are part of the analysed CFSR dataset) are identified as the coldest winters. It is known from visual observations that during the winter of 1963 the seawater was also not frozen and although floating ice was observed, this was expected to originate from inshore waters floating in offshore direction.

        Furthermore, it is noted that the surface water temperature increased in the North Sea since 1970 in the order of 0.5-1.0°C and the seawater temperature near the bottom increased in the North Sea 1~6°C during the last 25 years.