Synergy within MARSAIS

MARSAIS combines data from SAR sensors with those acquired by either optical or thermal infrared sensors. The aim of this is a better understanding of physical and bio-physical processes in the coastal zone than could be achieved with the help of SAR analysis alone.

Eddies - Example 4: North Aegean Sea

Map of Aegan Sea with location of SAR image

(a) Map showing the location of the SAR image in (b).

This example demonstrates the advantages of temporal coverage when data from a variety of sensors are included in a study. The map in (a) shows the location of an ERS-2 SAR image acquired on August 20, 2001 at 09:02 UTC which is shown in figure (b). The SAR image exhibits signatures of natural surface films which are visible as thin dark lines which have a spiral shape. This indicates the presence of an eddy with a diameter of approximately 30km (click on the image in (b) to see a larger version). Figure (c) shows the SAR signatures of the eddies enlarged.

ERS-2 SAR image, 20 August 2001, 09:02 UTC, Aegean Sea

AVHRR derived SST image, 19 August 2001, Aegean Sea

This animation consists of four AVHRR derived SST images acquired over the same region as the SAR image in (b) during 4 days (19-22 August 2001). Each of the images shows the location of a warm-core eddy located in the top left corner of the images, coinciding with the SAR signatures shown in (c). The four individual SST images are shown below. Note the differences in temperature between those images acquired during night time (e and f) and those acquired during day time (g and h).


AVHRR images acquired on (e) 19 August 2001 at 01:34 UTC, (f) 20 August 2001 at 01:23 UTC, (g) 22 August 2001 at 12:38 UTC, (h) 22 August 2001 at 15:27 UTC. © 2001 NOAA