Remedy 3: Establish an ocean emissivity reference model in the spectral region 1 – 200 GHz

Primary gap remedy type: 
Proposed remedy description: 

Undertake the necessary research and modelling to establish a reference emissivity model where the constituent parts have associated robust traceable uncertainties. This should include a re-calibration of the dielectric constant model to new reference laboratory measurements of the dielectric constant of seawater (see Remedy 4). A roughness model which, incorporates information from a wave model (large scale ocean swell) and surface wind speed (influencing small scale ripples and waves) is also needed to predict scattering characteristics. Similarly, the contribution of foam can be derived in principle from a wave model and full radiative transfer (rather than assuming a nominal emissivity value for the foam fraction). These activities will require coordination. Traceable uncertainty estimation must be assured at each step, the documented code should be freely available, and the final reference model should be maintained and supported.


Current fast emissivity models lack traceable uncertainty estimates which is a key source of uncertainty in the radiative transfer modelling of surface-sensitive microwave satellite observations over ocean in the 1-200 GHz range.

Measurable outcome of success: 

Documented and freely available software for the prediction of microwave ocean emissivity. The reference model constituent parts should have rigorous uncertainty estimates attached. The underlying basis of the model should be peer reviewed. The expertise for undertaking the necessary laboratory and modelling activities exists, but in disparate institutions that will require coordination. Establishing a fully characterised reference model would close this gap.

Expected viability for the outcome of success: 
  • Medium
Scale of work: 
  • Consortium
Time bound to remedy: 
  • Less than 5 years
Indicative cost estimate (investment): 
  • Medium cost (< 5 million)
Indicative cost estimate (exploitation): 
  • No
Potential actors: 
  • National funding agencies
  • National Meteorological Services
  • Academia, individual research institutes