 |
| Titel |
Hydrological changes in the Ligurian Sea (NW Mediterranean, DYFAMED site) during 1995–2007 and biogeochemical consequences |
| VerfasserIn |
J. C. Marty, J. Chiavérini |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 7, no. 7 ; Nr. 7, no. 7 (2010-07-07), S.2117-2128 |
| Datensatznummer |
250004892
|
| Publikation (Nr.) |
 copernicus.org/bg-7-2117-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Data obtained during the monthly cruises of the DYFAMED time-series study
(northwestern Mediterranean Sea) in the period 1995–2007 were compiled to
examine the hydrological changes and the linked variation of some
biogeochemical characteristics (nutrients and pigments). A regular increase
of temperature and salinity (0.005 °C y−1, 0.0022 psu y−1) was
recorded in deep waters of the NW Mediterranean Sea (2000 m depth) during
1995–2005. In February 2006 an abrupt increase in T (+0.1 °C) and
S
(+0.03 psu) was measured at 2000 m depth as the result of successive intense
winter mixing events during the 3 previous years. The February 2006 event
led to the mixing of the whole water column (0 to >2000 m) and increased
salt and heat content of the Western Mediterranean Deep Water by mixing with
saltier and warmer Levantine Intermediate Water. The deficit in fresh water
inputs to the western Mediterranean basin in three successive years
(2003–2005) was suspected to be the major cause of this event since an
increase of salinity in surface waters was monitored during these years. The
measured phytoplankton biomass was specifically high after the periods of
intense mixing. Chlorophyll a integrated biomass reached 230 mg m−2 in
1999, 175 mg m−2 in 2003, and 206 mg m−2 in 2006. The high levels
of biomass were related to the particularly high increases in nutrients
content in surface layers following the intense water column mixing and the
subsequent development of a diatom bloom (as seen by fucoxanthin content).
The occurrence of extreme events (high mixing, high nutrients, and high
biomass) increased in recent drought years (2003 to 2006). Our results
indicated that the NW Mediterranean Sea productivity is increasing. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|