469
Views
16
CrossRef citations to date
0
Altmetric
Research Article

Marine GIS: Identification of mesoscale oceanic thermal fronts

, &
Pages 1131-1147 | Received 13 Jan 2005, Accepted 10 Mar 2005, Published online: 20 Feb 2007
 

Abstract

A new method (the ‘sink’ method) is proposed for the mapping of productive mesoscale oceanic thermal fronts based on the combined analysis of satellite imagery for sea surface temperature (SST) distribution and chlorophyll (CHL) concentration under a Geographic Information System (GIS). In an SST lattice data array, data value sinks describe heterogeneous drops in SST distribution as this is compared to more homogeneously distributed SST in the surrounding area. Using Arc/Info GIS, these thermal discontinuities are flagged and applied on SST and CHL imagery for the calculation of differences in SST and CHL patterns (DSST and DCHL) inside and outside of these flagged areas. Spatially connected sinks that are characterized by simultaneous negative DSST and positive DCHL pattern are mapped as thermal fronts. Results include a time series of monthly front occurrence GIS maps in Eastern Mediterranean waters along with three calculated front characteristics (DSST, DCHL and bathymetry). Comparisons between the mapped fronts and isobath distributions present clearly visible front‐to‐isobath spatial and shape associations while spatial analysis between front and wind data explains 66% of the number of mapped fronts.

Acknowledgements

This work was partly funded by a European Communities (Fifth Framework Programme) research project (CEPHSTOCK QOL‐2001‐5.1.2) and a Hellenic Secretariat of Research and Technology (Ministry of Development) project (IMAS E2050‐5/1). The authors thank the SeaWiFS Project and the Distributed Active Archive Centre at the Goddard Space Flight Centre, Greenbelt, MD 20771, for the production and distribution of SeaWIFS data, the German Aerospace Agency for the distribution of AVHRR data as well as two anonymous referees for constructive comments on the manuscript.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.