Explanations

Difference between the extreme values of salinity during a complete tidal cycle (period between two subsequent slack water times of ebb current).

left top: value of characteristic number for a single event.
left bottom: mean value of the characteristic number within the period of data analysis.
right top: maximum value of the characteristic number within the period of data analysis.
right bottom: minimum value of the characteristic number within the period of data analysis.

Examples

tidal variation of salinity	tidal variation of salinity (maximum)

tidal variation of salinity (mean)	tidal variation of salinity (minimum)