Sea surface. The total reflectance over sea surfaces is defined as being composed of three terms, representing three different sources of upwelling radiance fields. Firstly, light can be reflected off white caps in the rough ocean surface; secondly, it can be reflected off the sea surface itself. The relative contributions from these two factors will depend on the roughness of the sea surface, which is dependent on the surface wind speed vz0 . Thirdly, light penetrating the surface can be scattered back up into the atmosphere by molecules within the water, such as water and dissolved pigments. Considering the combination of these terms, the sea surface reflectance in spectral band λ˜ writes rs(x, b; m) = ρwc(vz0 ; λ˜) + (1 − W )ρgl(vz0 ; λ˜) + (1 − ρgl(vz0 ; λ˜))ρsw (10) where ρwc is the reflectance due to white caps ρgl is the specular reflectance at the ocean surface ρsw is the scattered reflectance emerging from sea water W is the relative area covered with white caps vz0 is the surface wind speed. The reflectance of the white cap is taken from Xxxxxx (1984) and the specular contribution from Cox and Xxxx (1954). For the scattered reflectance emerging from sea water, a constant chlorophyll concentration of 0.1 [mg/m3] is assumed (Xxxxx 1988).
Sea surface. The total reflectance over sea surfaces is defined as being composed of three terms, representing three different sources of upwelling radiance fields. Firstly, light can be reflected off white caps in the rough ocean surface; secondly, it can be reflected off the sea surface itself. The relative contributions from these two factors will depend on the roughness of the sea surface, which is dependent on the surface wind speed vz0 . Thirdly, light penetrating the surface can be scattered back up into the atmosphere by molecules within the water, such as water and dissolved pigments. Considering the combination of these terms, the sea surface reflectance in spectral band λ˜ writes rs(x, b; m) = ρwc(vz0 ; λ˜) + (1 − W )ρgl(vz0 ; λ˜) + (1 − ρgl(vz0 ; λ˜))ρsw (10) where Aerosol-CCI+ ATBD XXXXX-SLSTR REF. : Aerosol_cci+_ATBD_C ISSUE : V1.2 DATE : December 2021 PAGE : 6 ρwc is the reflectance due to white caps ρgl is the specular reflectance at the ocean surface ρsw is the scattered reflectance emerging from sea water W is the relative area covered with white caps vz0 is the surface wind speed. The reflectance of the white cap is taken from Xxxxxx (1984) and the specular contribution from Cox and Xxxx (1954). For the scattered reflectance emerging from sea water, a constant chlorophyll concentration of 0.1 [mg/m3] is assumed (Xxxxx 1988).
