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Sea level: measuring the bounding surfaces of the ocean.

Tamisiea ME, Hughes CW, Williams SD, Bingley RM - Philos Trans A Math Phys Eng Sci (2014)

Bottom Line: The practical need to understand sea level along the coasts, such as for safe navigation given the spatially variable tides, has resulted in tide gauge observations having the distinction of being some of the longest instrumental ocean records.Archives of these records, along with geological constraints, have allowed us to identify the century-scale rise in global sea level.Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of sea-level rise and the mechanisms leading to spatial variability in the observed rates.

View Article: PubMed Central - PubMed

Affiliation: National Oceanography Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK mtam@noc.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Simple schematic illustrating the relationship between sea surface height (SSH), the geoid, and dynamic topography. Included on the figure are representations of different components of the observing system and their respective measurement: GPS (or GNSS) for crustal deformation, satellite gravity for the geoid, altimetry for SSH and tide gauges for relative sea level. (Online version in colour.)
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RSTA20130336F1: Simple schematic illustrating the relationship between sea surface height (SSH), the geoid, and dynamic topography. Included on the figure are representations of different components of the observing system and their respective measurement: GPS (or GNSS) for crustal deformation, satellite gravity for the geoid, altimetry for SSH and tide gauges for relative sea level. (Online version in colour.)

Mentions: Before exploring the geodetic aspects of sea level, we should review how sea-level changes are viewed in oceanography. In the absence of dynamics or other external forcing, the surface of the ocean should lie on an equipotential of the Earth's gravity field, called the geoid. In the vast majority of ocean models and theoretical studies, this surface is represented by a constant value of the vertical coordinate z. It is important, therefore, to recognize that z is not simply a geometrical coordinate, but is defined by the Earth's gravity field. With the exception of global tide models, which explicitly account for solid Earth deformation and changes to the gravity field (loading and self-attraction), most ocean models assume both bathymetry and the z-coordinate to be fixed relative to the rotating Earth. The deviation of the ocean's surface, or the sea surface height (SSH), from the geoid is called dynamic (ocean) topography (figure 1). Winds, together with atmospheric pressure and surface fluxes of heat and freshwater, determine the dynamic topography (the response to tidal forces is usually considered separately).Figure 1.


Sea level: measuring the bounding surfaces of the ocean.

Tamisiea ME, Hughes CW, Williams SD, Bingley RM - Philos Trans A Math Phys Eng Sci (2014)

Simple schematic illustrating the relationship between sea surface height (SSH), the geoid, and dynamic topography. Included on the figure are representations of different components of the observing system and their respective measurement: GPS (or GNSS) for crustal deformation, satellite gravity for the geoid, altimetry for SSH and tide gauges for relative sea level. (Online version in colour.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150292&req=5

RSTA20130336F1: Simple schematic illustrating the relationship between sea surface height (SSH), the geoid, and dynamic topography. Included on the figure are representations of different components of the observing system and their respective measurement: GPS (or GNSS) for crustal deformation, satellite gravity for the geoid, altimetry for SSH and tide gauges for relative sea level. (Online version in colour.)
Mentions: Before exploring the geodetic aspects of sea level, we should review how sea-level changes are viewed in oceanography. In the absence of dynamics or other external forcing, the surface of the ocean should lie on an equipotential of the Earth's gravity field, called the geoid. In the vast majority of ocean models and theoretical studies, this surface is represented by a constant value of the vertical coordinate z. It is important, therefore, to recognize that z is not simply a geometrical coordinate, but is defined by the Earth's gravity field. With the exception of global tide models, which explicitly account for solid Earth deformation and changes to the gravity field (loading and self-attraction), most ocean models assume both bathymetry and the z-coordinate to be fixed relative to the rotating Earth. The deviation of the ocean's surface, or the sea surface height (SSH), from the geoid is called dynamic (ocean) topography (figure 1). Winds, together with atmospheric pressure and surface fluxes of heat and freshwater, determine the dynamic topography (the response to tidal forces is usually considered separately).Figure 1.

Bottom Line: The practical need to understand sea level along the coasts, such as for safe navigation given the spatially variable tides, has resulted in tide gauge observations having the distinction of being some of the longest instrumental ocean records.Archives of these records, along with geological constraints, have allowed us to identify the century-scale rise in global sea level.Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of sea-level rise and the mechanisms leading to spatial variability in the observed rates.

View Article: PubMed Central - PubMed

Affiliation: National Oceanography Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK mtam@noc.ac.uk.

No MeSH data available.


Related in: MedlinePlus