Marigram
Graphic showing variations of the sea level, in a single location, as a function of time.
MARIS
Marine Observations Service.
Mean anomaly
Angle between the direction of the mean sun and that of the perihelion.
Mean high water lunitidal interval
Mean interval between the time of high water and the Moon's meridian passage.
mean level
Result of a digital filtering of the heights observed tending to eliminate the sinusoidal components.
Mean longitude
Ecliptic longitude of a celestial body or an element of its orbit. This designation is not really apposite (it is not the mean of the longitudes), but it is the term generally used.
Mean ocean surface
Surface of the oceans determined by space altimetry.
Mean Sun
Fictitious celestial body having the same apparent period of revolution as the true Sun, but with uniform motion. The mean time varies by 0 to 24 hours from the passage of the mean Sun through the upper meridian.
Mean time
Uniform time scale defined by the mean Sun. By definition, a mean time day is 24 hours in length.
MEDDTL
Ministère de l'écologie, du développement durable, des transports et du logement (Ministry for ecology, sustainable development, transport and housing)
Meridian plane
Plane containing the polar axis.
Meshing
Subdivision of an area into simple geometric elements with a view to carrying out mathematical modelling.
MESR
Ministère de l'enseignement supérieur et de la recherche (Ministry for higher education and research).
MIOMCTI
Ministère de l'intérieur, de l'outre-mer, des collectivités territoriales et de l'immigration (Ministry of the interior, overseas territories, territorial communities and immigration).
Mixed tide
Sometimes two high waters and two low waters per day, at other times one high water and one low water per day; the diurnal components are dominant.