@prefix dct: . @prefix ns1: . @prefix ns2: . @prefix ns3: . @prefix rdfs: . @prefix skos: . a skos:Concept ; dct:created "2019-01-14" ; dct:modified "2019-01-14" ; ns3:hasProfile ; ns2:status ; rdfs:seeAlso ; skos:definition "The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. A coordinate variable of radiation_wavelength or radiation_frequency can be specified to indicate that the optical thickness applies at specific wavelengths or frequencies. Layer means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers"@en ; skos:exactMatch ; skos:prefLabel "optical thickness of atmosphere layer due to ambient aerosol particles"@en ; ns1:hadPrimarySource .