Sea Level

Calm sea bordered by rocky cliffs, with overcast sky. Text overlay: "Sea Level Essential Climate Variable (ECV) Factsheet - Global Climate Observing System.
Sea Level is one of the primary indicators of global climate change. Change in the global mean sea level provides a measure of the net change in ocean mass due to melting of glaciers and ice sheets, and net change in ocean volume due to thermal expansion. Sea level observations characterize inter-seasonal variability such as ENSO. On the regional scales, changes in sea level can be far larger than the globally averaged value due to changes in temperature, salinity and circulation. Along many continental margins vertical land displacement associated with crustal adjustments to past and current land ice melt also cause regional variations in apparent sea level independent of the ocean. Coastal sea level change is a major driver of societal impacts.

Sea Level Rise Map and Global Trend

Figure 1: Combined map of regional patterns of observed sea level (in mm/year). This map can be obtained using gridded, multi-mission Ssalto/Duacs data since 1993, which enable the local slopes to be estimated with a very high resolution (1/4 of a degree on a Cartesian projection). Isolated variations in MSL are thus revealed, mainly in the major ocean currents and ENSO events (Credits EU Copernicus Marine Service, CLS, Cnes, Legos).

Source: https://www.aviso.altimetry.fr/en/data/products/ocean-indicators-produc…

ECV Products and Requirements

These products and requirements reflect the Implementation Plan 2022 (GCOS-244).

The requirements are found in the complete 2022 ECVs Requirements document as well: ECV Sea Level.

Products Regional Mean Sea Level  Global Mean Sea Level
 (*)UnitValues UnitValues
Horizontal ResolutionGkm10 km10
B   
T100 100
Vertical ResolutionG -  -
B- -
T- -
Temporal ResolutionGd1 d1
B   
T7 30
TimelinessGmonth1 d30
B   
T12 365
Required Measurement Uncertainty (2-sigma)Gmm  mm 
B   
T10 2-4
StabilityGmm yr-10.3 mm yr-1<0.03
B  <0.1
T<0.1 <0.3

(*) Goal (G): an ideal requirement above which further improvements are not necessary. Breakthrough (B): an intermediate level between threshold and goal which, if achieved, would result in a significant improvement for the targeted application. The breakthrough value may also indicate the level at which specified uses within climate monitoring become possible. It may be appropriate to have different breakthrough values for different uses. Threshold (T): the minimum requirement to be met to ensure that data are useful

Data sources

This list provides sources for openly accessible data sets with worldwide coverage for which metadata is available. It is curated by the respective GCOS ECV Steward(s). The list does not claim to be complete. Anyone with a suitable dataset who wishes it to be added to this list should contact the abombelliatwmo [dot] int (GCOS Secretariat).

In Situ

  • GLOSS - Global Sea-Level Observing System

Satellite:

Sea level
Domain:
Ocean
Subdomain:
Physical
Scientific Area:
Physical Properties
ECV Steward:
Peter Oke
Products:
Regional Mean Sea Level; Global Mean Sea Level