Oceanographic Structures of Small Scale Phenomena Detected by Satellite Infrared Images
1991 Volume 11 Issue 2 Pages 304-311
Details
1991 Volume 11 Issue 2 Pages 304-311
Satellite infrared sensors can detect a lot of small scale phenomena at the sea surface such as streamers, warm tongues, frontal eddies and the others, which cannot be found out by old hydrographic surveys. But there remains some issues whether all of these phenomena are real one, because the satellite sensors observe just sea surface where the air-sea interaction is very active. So we have to distinguish that which kind of phenomena are real one or only illusion. In this paper, structures of some streamers and a warm tongue, which were observed on board the R/V Soyo Maru and by satellite NOAA AVHRR, will be presented.
A cold streamer around the Kuroshio warm-core ring was derived from NOAA-9 AVHRR infrared images during June 8-13, 1986. The streamer was observed in late June, 1986. A cold low-salinity band, which was 2 to 20 km wide, more than 200 km long and more than 500 m deep, existed around the warm-core ring with geostrophic structure.
On 15 May 1989, a warm streamer around the Kuroshio warm-core ring was visible in a NOAA-10 AVHRR image. The warm streamer was observed on board the R/V Soyo Maru during May 20 -22, 1989. The warm streamer had a structure deeper than 500 m depth. And also another warm streamer was observed in the warm-core ring.
A warm tongue was detected in a NOAA-9 AVHRR image on 1 September 1987 in the northwestern part of the warm-core ring. A temperature section, which was observed during 5-21 September 1987, shows that the warm tongue was 300 m in thickness.
A warm streamer was derived from a NOAA-10 infrared image on 18 May 1988 in Enshu-nada sea. Observations by only one section was conducted across this warm streamer during May 15-21, 1988. Warm water and cold water were recognized by turns in a temperature section. The geostrophic current relative to 1000 m deep in this. section suggests that an anticlockwise current around the warm streamer, which also coincides with the satellite image.
All of these four phenomena detected by satellites actually exist and have deep structures. So satellite data are very useful for oceanographic studies.
