Mediterranean WaterMediterranean Water

Mediterranean water in the Atlantic, Mediterranean water in the Atlantic, Levantine Intermediate Water (LIW), Levantine Intermediate Water (LIW), Adriatic/ Ionian/ West Mediterranean Adriatic/ Ionian/ West Mediterranean

deep water deep water

Table of contentTable of content

• Seas at stake

• Mediterranean Water

• Circulations in the Mediterranean Sea

The term The term MediterraneanMediterranean derives from the derives from the LatinLatin mediterraneusmediterraneus, 'inland' (, 'inland' (mediusmedius, 'middle' + , 'middle' + terraterra, 'land, , 'land, earth'),earth'),The Mediterranean Sea has been known by a number of alternative names throughout human The Mediterranean Sea has been known by a number of alternative names throughout human history.:history.:Mare NostrumMare Nostrum (Latin, (Latin, Our SeaOur Sea) by the Romans. In the ) by the Romans. In the BibleBible, it is referred to as the Great Sea. In , it is referred to as the Great Sea. In modern modern HebrewHebrew, it is called "ha-Yam ha-Tichon" (, it is called "ha-Yam ha-Tichon" ( התיכון התיכון הים ,"the middle sea",), "the middle sea" ,(הים

Mediterranean Sea

Adriatic SeaAdriatic Sea

• The Adriatic Sea is an arm of the Mediterranean See separating the Apennine peninsula (Italy) from the Balkans

• The name has existed since the antiquity; in Latin it was Mare Hadriaticum. In modern languages, it is Mare Adriatico in Italian

Ionian SeaIonian Sea

• The Ionian Sea (Greek Ιόνιο Πέλαγος, Italian Mare Ionio) is an arm of the Mediterranean Sea, south of the Adriatic Sea

• Ionius was the son of King Adrias of Illyria who gave his name to the Adriatic.

• The sea is one of the most seismic areas in the world.

Mediterranean watersMediterranean waters

• The Mediterranean sea is composed of a series of adjacent water masses

• The temperature, salinity, and density vary dramatically from one water mass to the next.

Mediterranean WatersMediterranean Waters

• Mediterranean Sea very salty and warm:

• Average temperature: 13C

• Average Salinity : 37 ppt

• Sea with most evaporation! uncommon

Mediterranean WatersMediterranean Waters

• During the last decade, oceanographers have focused much attention on the Mediterranean Sea

• One reason for the growing interest is that the Mediterranean affects the Northern Atlantic Ocean much more than previously realized:

• The second reason is the well-recognized role of the

Mediterranean Sea as a laboratory for studying ocean processes that are important to global climate.

Mediteranean WatersMediteranean Waters

•  The Mediterranean Sea is essentially divided into two basins, the eastern and the western

• The basins are separated by the shallow Sicily Straits, which prevent the water masses from the deep and bottom layers of the two basins from mixing

Mediterranean WatersMediterranean Waters

• three convection areas: • The Gulf of Lion which

produces West Mediterranean Deep Water (WMDW)

• the Adriatic Sea which produces East Mediterranean Deep Water (EMDW)

• Levantine Basin which generates Levantine Intermediate Water (LIW)

Mediterranean WaterMediterranean Water

• Mediterranean hydrodynamics are driven by three layers of water masses: a surface layer, an intermediate layer, and a deep layer that sinks to the bottom

Mediterranean WaterMediterranean Water• surface layer : thickness varying from 250 to 1,000 feet

• intermediate layer : warm and saline water coming from the eastern Mediterranean

characterized by temperature and salinity maxima at 1,300 feet

situated at depths between 1,000 and 2,000 feet

• deep layer : occupies the remaining zone between the intermediate layer and the bottom.

In general, the water of this layer is very homogeneous.

CirculationCirculation

• Flow from the rivers into Mediterrane = about one-third of the water lost by evaporation

• In consequence : continuous inflow of surface water from the Atlantic Ocean :

• After passing through the Strait of Gibraltar, the main body of the incoming surface water flows eastward along the north coast of Africa

Circulation Circulation

•  This current is the most constant component of the circulation of the Mediterranean.

• more powerful in summer, when evaporation in the Mediterranean is at a maximum.

• This inflow of Atlantic water loses its strength as it proceeds eastward

CirculationCirculation

• Surface circulation : separate counterclockwise movement of the water in each of the two basins

• complexity of the northern coastline and of the numerous islands: many small eddies

CirculationCirculation

• Winter: inland winds (Mistral and Tramontane) are dry and cold

• Therefore convection in West Mediterranean generates deep water

• Mediterranean surface water becomes more saline through the intense evaporation

• Therefore: its density increases • Therefore: It sinks• The excess of this denser bottom water emerges into the

Atlantic Ocean over the Strait of Gibraltar :• westward subsurface current below the inward current

CirculationCirculation

• The inflowing water extends from the surface down to 230 or 260 feet.

• The outflowing waters is below

• The Mediterranean has been metaphorically described as breathing:

inhaling surface water from the Atlantic and exhaling deep water in a countercurrent below