Mediterranean Water
Mediterranean water in the Atlantic,
Levantine Intermediate Water (LIW),
Adriatic/ Ionian/ West Mediterranean
deep water
Table of content
• Seas at stake
• Mediterranean Water
• Circulations in the Mediterranean Sea
Mediterranean Sea
The term Mediterranean derives from the Latin mediterraneus, 'inland' (medius, 'middle' + terra, 'land,
earth'),
The Mediterranean Sea has been known by a number of alternative names throughout human history.:
Mare Nostrum (Latin, Our Sea) by the Romans. In the Bible, it is referred to as the Great Sea. In
modern Hebrew, it is called "ha-Yam ha-Tichon" (‫)הים התיכון‬, "the middle sea",
Adriatic 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 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 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 Waters
• Mediterranean Sea very salty and warm:
• Average temperature: 13C
• Average Salinity : 37 ppt
• Sea with most evaporation! uncommon
Mediterranean 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 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 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 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 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.
Circulation
• Flow from the rivers into Mediterrane = about onethird 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
•
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
Circulation
• 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
Circulation
• 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
Circulation
• 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