Remote imaging of internal solitons in the coastal ocean

During a combined in situ and airborne remote sensing exercise off Oceansid e, CA? a Compact Airborne Spectrographic Imager (CASI) observed alongshore lineations: which were associated with an internal soliton packet accompany ing a tidally generated internal solitary wave (solibore). The soliton pack ets were most evident in the images at green wavelengths, which penetrate t he deepest into the water column. and only weakly evident at optical wavele ngths with shallower penetration. We believe that this is the first observa tion of internal soliton packets determined from remotely sensed upwelled r adiance. We hypothesize that the lineations were produced by changes in the upwelling radiance from the interior of the water column: not by changes i n surface reflectance. Using a simulation, it is demonstrated that such lin eations carl be produced by vertical modulation of the inherent optical pro perties (IOPs) during the passage of the internal soliton packet. Since sur face manifestations ale not always present, this opens the potential for br oadly based inventories of internal solitons in coastal waters. (C) 2001 Pu blished by Elsevier Science Inc.