Sea State

Sea State is the characterization of wave and swell, typically in terms of height, wavelength, period, and directional wave energy flux. Waves generated by ocean surface stress evolve from wind waves to swell through nonlinear dynamical processes.. Wave characteristics are modified by bathymetry when the depth of the water is comparable to the wavelength, and by surface currents. Sea state is most well known for its impacts on marine safety, marine transport and damage to structures. It is also a substantial modifier of air-sea exchanges of momentum, moisture and CO2. Waves also impact beach erosion, storm-related water damage (wave set-up contributes to storm surge), surface albedo, and transport of larva. Waves can also modify the growth or decay of sea ice.

Map of Wave Height

Figure: Annual Mean significant wave height in m, measured by the Jason-1 Satellite.

Source: https://www.aviso.altimetry.fr/en/data/data-access/las-live-access-serv….

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 State.

Products			Wave Height
	*()**	Unit	Values
Horizontal Resolution	G	km	1
	B		25
	T		100
Vertical Resolution	G		-
	B		-
	T		-
Temporal Resolution	G	h	1
	B		3
	T		24
Timeliness	G	d	7
	B		30
	T		365
Required Measurement Uncertainty (2-sigma)	G	%	5
	B
	T
Stability	G	cm/ decade	1
	B
	T		10

(*) 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 GCOS Secretariat.

National Centers for Environmental Information (NCEI)
British Oceanographic Data Center (BODC)
Marine Environment Data & Information Network (MEDIN)
AVISO
ECV Inventory by the CEOS/CGMS Working Group on Climate (WGclimate)