Measurements at 13.9 GHz of the radar backscattering cross section of the North Sea covered with an artificial surface film
Article first published online: 7 DEC 2012
Copyright 1978 by the American Geophysical Union.
Volume 13, Issue 6, pages 979–983, November-December 1978
How to Cite
1978), Measurements at 13.9 GHz of the radar backscattering cross section of the North Sea covered with an artificial surface film, Radio Sci., 13(6), 979–983, doi:10.1029/RS013i006p00979., , and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Received: 5 JAN 1978
The reduction of the Ku-band (13.9 GHz) normalized radar cross section (NRCS) by an artificial monomolecular surface film (oleyl alcohol) on the sea surface was measured in the North Sea during the 1975 Joint North Sea Wave Project, JONSWAP 75 experiment. The aim of the surface film experiment was to simulate natural surface films which often occur on the ocean surface and are produced by plankton or fish. NRCS measurements were obtained from an aircraft at incidence angles of 41° and 47° at vertical and horizontal polarizations. For winds between 3.5 and 4.4 m/sec the maximum measured reduction was 7.3 ± 3.5 dB relative to the mean. In-situ measurements showed that the oleyl alcohol film reduced the surface tension from 74 to 43 dyne/cm. Similar reductions in surface tension have also been measured on the ocean due to natural surface films of biological origin. It is noted that variations of the NRCS due to natural surface film effects may significantly limit the techniques used currently to infer surface wind vector over biologically active ocean regions.