The Atlantic ionian stream

This paper describes some preliminary results of the cooperative effort bet ween SACLANT Undersea Research Centre and Harvard University in the develop ment of a regional descriptive and predictive capability for the Strait of Sicily. The aims of the work have been to: (1) determine and describe the u nderlying dynamics of the region; and, (2) rapidly assess synoptic oceanogr aphic conditions through measurements and modeling. Based on the 1993-1996 surveys, a picture of some semi-permanent features which occur in the Strai t of Sicily is beginning to emerge. Dynamical circulation studies, with ass imilated data from the surveys, indicate the presence of an Adventure Bank Vortex (ABV), Maltese Channel Crest (MCC). and Ionian Shelf Break Vortex (I BV). A schematic water mass model has been developed for the region. Result s from the Rapid Response 96 real-time numerical modeling experiments are p resented and evaluated. A newly developed data assimilation methodology, Er ror Subspace Statistical Estimation (ESSE) is introduced. The ideal Error S ubspace spans and tracks the scales and processes where the dominant, most energetic, errors occur, making this methodology especially useful in real- time adaptive sampling. (C) 1999 Elsevier Science B.V. All rights reserved.