Discussion of the Ionian and Levantine Seas, NATO workshop on atmospheric and oceanic circulation in the Mediterranean basin
The Levantine Intermediate Water (LIW) is the most critical water mass in the thermohaline heart of the Mediterranean. It is comprised of North Atlantic Water (NAW) which was transformed to salty water (36.2 to 39.2 ppt). In the eastern Mediterranean (EMED) the NAW changes to a warm saline surface layer and a cool less saline layer. Much of the LIW is produced from winter cooling of surface waters. The distribution is patchy, dependant on original surface type, circulation, and atmospheric exposure. Convective depths range to 400 m; the densest water not necessarily correlated with the deepest convective layers. Survival of the LIW depends on circulation and density. The circulation of the EMED is barotropically controlled by sea level. The annual low frequency signal is a trough extending zonally south of center and deepening eastward. The resulting cyclonic circulation is skewed to the south and east. The westerly winds exaggerate the African eastward coastal flow. Wind stress, positive curl in northern Levantine and negative curl in the Gulf of Sirte, contribute to the circulations. Higher frequency variations in water loss impose barotropic noise on the lower-frequency pattern; higher frequency wind energy affects surface circulations and deeper barotropic flows. The internal pressure gradient, resulting from the denser LIW, causes the westward return flow on the northern side within the LIW layer. The deep layers lack potential to drive baroclinic shear; consequently, they react to any unadjusted barotropic pressure gradients. This is substantial even at low frequencies. Deep Water tends to follow the basic barotropic pattern, flowing eastward along the African coast beneath the NAW. 22 references, 11 figures.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6808446
- Report Number(s):
- BNL-34653; CONF-8309237-1; ON: DE84011562
- Resource Relation:
- Conference: NATO workshop on atmospheric and oceanic circulation in the Mediterranean Basin, Santa Teresa, Italy, 7 Sep 1983; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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