Word
> "Mot"
 Symbol
 Unity
 Definition

Maximum zero downcrossing wave height
> "Hauteur maximale par valeurs décroissantes"
 Hmax,d
 m

The maximum height of the zero downcrossing waves in a wave train.

Maximum zero upcrossing wave height
> "Hauteur maximale par valeurs croissantes"
 Hmax,u
 m

The maximum height of the zero upcrossing waves in a wave train.

Spectral moment
> "Moment de densité spectrale"
 mn
 m2/sn

The nth moment of spectral density. > see form

Mean diurnal tide level
> "Niveau moyen de marée diurne"
 MDTL


Midlevel between "Mean lower low water" and "Mean higher high water".

Mean higher high water
> "Plus haut niveau moyen de marée haute"
 MHHW


The average of the higher "Highest astronomical tide" heights of each tidal oscillation observed over a period of 19 years.

Mean high water
> "Marée haute moyenne"
 MHW


The average of the "Highest astronomical tide" heights observed over the duration of "Tide periodicity".

Mean high water springs
> "Marée haute moyenne de Vives Eaux"
 MHWS


The arithmetic mean of the high water heights at the times of spring tides.
Also called spring high water.

Mean lower low water
> "Plus bas "Niveau de marée basse""
 MLLW


The average of the lowest low water heights of each tidal oscillation observed over a period of 19 years.

Mean low water
> "Marée basse moyenne"
 MLW


The average of all the "Low water" heights observed over the duration of "Tide periodicity".

Mean low water springs
> "Marée basse moyenne de Vives Eaux"
 MLWS


The arithmetic mean of the "Low water" heights at the times of spring tides observed over the duration of "Tide periodicity".
Also called "Spring low water".

Mean spectral period
> "Période spectrale moyenne"
 T01
 s

The period corresponding to the average frequency of the spectrum.
See also"Spectral wave period".

Mean range of tide
> "Niveau moyen de marée"



The difference between the "Mean high water" height and the "Mean low water" height.

Mean rise
> "Elévation moyenne"



The height of "Mean high water" above the elevation of chart datum.

Mean river level
> "Niveau moyen d'une rivière"



The average height of the surface of a "Tidal river" for all the tides observed over the duration of "Tide periodicity".

Mean sea level
> "Niveau moyen de la mer"
 MSL


The mean of the water surface elevation observed over the duration of "Tide periodicity".

Mean tide level
> "Niveau moyen de marée"



Midpoint between "Mean high water" and "Mean low water".

Mean water level
> "Niveau moyen d'eau"
 MWL


Midpoint between the "Lowest astronomical tide" and the "Highest astronomical tide".

Mean wave direction
> "Direction moyenne des vagues"
 m
 deg

Mean wave direction as a function of frequency [1].
"Direction of wave propagation", "Peak direction", "Wave direction".

Metonic cycle
> "Cycle métonique"



A period of almost 19 years (i.e.235 lunations) created by the Athenian astronomer Meton (5th century BC), to obtain a period in which new and full Moon recur on the same day.

Modal period
> "Période modale"
 Tp
 s

Same as "Peak period".

Monodirectional swell
> "Houle monodirectionnelle"



See "Irregular waves".

Multidirectional swell
> "Houle multidirectionnelle"



See "Irregular waves".
