Minimize Coastal Fronts

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Ocean fronts are boundaries between water masses with dissimilar properties. The dynamics by which the front is maintained between two water masses of different densities (due to different temperatures or/and salinities) causes convergences at the sea surface. The fronts are usually marked by an increase in surface roughness due to the interaction of the convergent surface flow with the surface waves and thus appear on SAR images as bright lines. But they also can be marked by a decrease in surface roughness due to the fact that in the convergent regions surface slicks accumulate which damp the surface waves.

Ocean fronts are often located near the coast. So-called "shelf break fronts" are formed at the edges of continental shelves where waters characteristic of shallow shelf regions meet with waters of the continental slopes and the deep ocean. So-called "shallow-sea fronts" are formed in shallow seas and estuaries where well-stratified offshore waters meet with coastal waters which are well-mixed by the action of the winds and the tides. Water near the coast often has a lower salinity than the waters further offshore because of inflow of fresh water from rivers.


References

  • Johannessen, J.A., Shuchman, R.A., Johannessen, O.M., Davidson, K.L. & Lyzenga, D.R., Synthetic aperture radar imaging of upper ocean circulation features and wind fronts. J. Geophys. Res., 96, No. C6, 10411-19422 (1991).
  • Johannessen, J.A., Shuchman, R.A., Digranes, G., Lyzenga, D.R., Wackerman, C., Johannessen, O.M. & Vachon, P.W., Coastal ocean fronts and eddies imaged with synthetic aperture radar. J. Geophys. Res., 101, 6651-6668 (1996).
  • Legeckis, R, A survey of worldwide sea surface temperature fronts detected by environmental satellites. J. Geophys. Res., 83, No. C9, 4501-4522 (1978).
  • Marmorino, G.O., Thompson, D.R., Graber, H.C. & Trump, C.L., Correlation of oceanographic signatures appearing in synthetic aperture radar and interferometric synthetic aperture radar imagery with in situ measurements. J. Geophys. Res., 102, No. C8, 18723-18736 (1997).