The Ierapetra gyre is a Mediterranean oceanic feature that pops up more or less regurlarly. This anticyclonic gyre (turning clockwise, since it is in the Northern hemisphere) forms as a result of wind interactions with the relief on Crete and of ocean circulation in the Kasos strait (Image of the Month, June 1999, An eddy blown by the wind). When it exists, it is visible as a "hill" on the ocean topography.

Since 1993, this gyre appeared -- or not -- depending on the periods. Between 1993 and 2001, it is clearly visible (which enabled to study its creation and evolution over several years); it disappeared in 2002, to reappear in July 2004. Since then, its activity is very similar to the one observed between 1993 and 2001: a marked seasonal cycle, with a maximum intensity in September/October.

Long-term monitoring of phenomena such as this Ierapetra gyre allows to better understand ocean circulation and its variations. By continuing the observations, we will better know the variations spanning over periods of several years.

See also:

• Applications: Mediterranean
• Applications: Ocean circulation and its variations
• Data: regional products -- Mediterranean (M)SLA

Websites on this subject:

• MFS project: Mediterranean Forecasting System

References:

• Hamad N., Millot C., Taupier-Letage I., 2006, The surface circulation in the eastern basin of the Mediterranean Sea, Scientia Marina 70 (3), 457-503
• Horton C., Clifford M., Schmitz J., Kantha L.H., 1997, A real time oceanographic nowcast/forecast system for the Mediterranean Sea, J. Geophys. Res. 102, 25123-25156.
• Larnicol G., Ayoub N., Le Traon P.-Y., 2002, Major changes in the Mediterranean Sea level variability from 7 years of TOPEX/Poseidon and ERS-1/2 data, J. Mar. Sys. 33-34, 63-89
• Pujol M.-I., 2006, "Analyse de la variabilité de surface en Méditerranée à partir des données altimétriques et comparaison aux simulations MERCATOR et MOG2D", These de l'Universite Paul Sabatier, Toulouse III.