Ocean Science
www.ocean-sci.net
1812-0784
1812-0792
4
2
2008
10.5194/os-4-133-2008
http://www.ocean-sci.net/4/133/2008/
http://www.ocean-sci.net/4/133/2008/os-4-133-2008.html
http://www.ocean-sci.net/4/133/2008/os-4-133-2008.pdf
133
149
2008-05-14
Observations of new western Mediterranean deep water formation using Argo floats 2004–2006
R. O. Smith
H. L. Bryden
hlb@noc.soton.ac.uk
K. Stansfield
National Oceanography Centre, Empress Dock, Southampton, SO14 3ZH, Hampshire, UK
The deep convection that occurs in the western basin of the Mediterranean
Sea was investigated using Argo float data over two consecutive winters in
2004–2005 and 2005–2006. The results showed deep mixed layers reaching 2000 m
in surprising locations, namely the eastern Catalan subbasin (39.785° N,
4.845° E) and the western Ligurian subbasin (43.392° N, 7.765° E).
Subsequently, new deep water was formed in March of 2005 and 2006 with
θ=12.89–12.92°C, <i>S</i>=38.48–38.49 and σ<sub>θ</sub>=29.113 kg m<sup>−3</sup>. The deep water produced in the Ligurian subbasin during
2006 was more saline, warmer and denser than any historical observations of
western Mediterranean deep water. The results show <i>S</i>, θ and σ<sub>θ</sub> in the western Mediterranean deep water are higher than 1990s
values, with a salinity increase of 1.5×10<sup>−3</sup> yr<sup>−1</sup>, a
temperature increase of 3.6×10<sup>−3</sup> °C yr<sup>−1</sup> and a density
increase of 4.0×10<sup>−4</sup> kg m<sup>−3</sup> yr<sup>−1</sup> apparent from a
dataset of western Mediterranean deep water properties spanning 1955–2006.
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