1. THE PHYSICAL BASIS OF SST MEASUREMENTS Diurnal Warming 1.Continue/expand research into development of diurnal warming models and analysis of satellite observed diurnal warming 2. Continue and expand research into the role of penetrating radiation and its relationship to available optical properties in the water column. 3. Improve specification of diurnal model uncertainty 4. Perform additional field observations of diurnal warming events. 5. Develop/enhance links with other communities with interests in diurnal warming such as the ocean color and the meteorological communities. Skin Effect 1.Undertake additional research into the physics and modeling of the skin effect. 2. Improve our understanding of how errors in model forcing parameters impact skin model errors

2. Spatial and/or Temporal Variability in SST Level 2: impact on the retrieval error Develop methods to integrate an improved understanding of the SST variability into the SST retrievals error. Expand the library of sub-pixel scale SST data sets. Investigate development of a high-resolution μ-wave sensor. Levels 3 and 4: Contribution to representation error To improve estimates of variance-covariance structure for representation error, based on the improved estimates and understanding of intra- gridbox space/time variability. Level 4: A priori estimates of SST autocovariance To improve estimates of the variance-covariance structure between SST averages over typical gridboxes of L4 products on the basis of recent/expected space-time SST variability research effort

3. Score System Magnitude of effect: Large Moderate Small Influence of the effect: Most observations Moderate numbers Few observations State of knowledge/consensus: Poorly understood Somewhat understood Well characterized

4. Scores of Main Physics Themes MagnitudeInfluenceKnowledgeScore Diurnal warming 3137 Cool skin 1326 Spatial variability 2338 Score 67821