mean sea level


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mean sea level

[′mēn ′sē ‚lev·əl]
(oceanography)
The average sea surface level for all stages of the tide over a 19-year period, usually determined from hourly height readings from a fixed reference level.

mean sea level

The average height of the surface of the sea for all stages of the tide. It is used as a reference for elevations. Usually, it is determined by averaging the height readings observed hourly over a minimum period of nineteen years. Also called sea-level datum.
References in periodicals archive ?
Thompson, 2015: Considerations for estimating the 20th century trend in global mean sea level. Geophys.
Over the period 1993-2010, global mean sea level rise is, with high confidence, consistent with the sum of the observed contributions from ocean thermal expansion, due to warming, from changes in glaciers, the Greenland ice sheet, the Antarctic ice sheet and land water storage." [Emphasis in original.]
These harmonics are visible as common cycles with periods 1-9, 12-19 and 23-33 years in various time series of Earth phenomena like Earth rotation, mean sea level, climate, etc.
This is the major reason for the changes in the projected rise in mean sea level. In particular, the values given in the Fourth Assessment Report (AR4), published in 2007, are relatively low.
This report exposed historical trends of global mean sea level from tide gauge records and the average sea level from global satellite measurements (Figure 1.2).
Some synoptical and dynamical quantities attain in this point, such as the mean sea level pressure and its anomaly, 500-hpa geopotential anomaly, relative vorticity advection and thermal vorticity advection and thickness advection.
Once constructed, these stations will be used to measure wave height, seabed terrain and weather data, such as wind speed and atmospheric pressure, in a bid to confirm and continuously observe the mean sea level.
This massive shared knowledge base will improve our understanding of climate change, global mean sea level rise, volcanoes and earthquakes.
More than 80 percent of the country's land, composed of coral islands scattered some 850 kilometers (530 miles) across the equator, is less than one meter (3.3 feet) above mean sea level
"The UK Military Low Flying System covers the open airspace of the whole of the UK and surrounding overseas areas from the surface to 2,000 feet above the ground or mean sea level.
Note 1: Decision altitude (DA) is referenced to mean sea level (MSL) and decision height (DH) is referenced to the threshold elevation."