G. Krahmann et F. Schott, LONG-TERM INCREASES IN WESTERN MEDITERRANEAN SALINITIES AND TEMPERATURES - ANTHROPOGENIC AND CLIMATIC SOURCES, Geophysical research letters, 25(22), 1998, pp. 4209-4212
The deep water of the western Mediterranean Sea is known to have becom
e warmer and saltier since about the 1950s. The causes of these change
s have, however, not yet been sactisfactorily determined. Previous stu
dies speculated on decreasing precipitation, greenhouse warming and/or
anthropogenic reduction of the freshwater flux into the eastern Medit
erranean. Here we report on results from a new oceanographic database
of the western Mediterranean Sea together with determinations of longt
erm changes of the fresh water budget. We analyzed temperature and sal
inity data of the past 40 years to detect deviations from the longterm
average. Certain areas and depth ranges are showing increases in temp
erature or salinity some of which have been found earlier and some whi
ch are new. From the regional and vertical distribution we conclude th
at the observed increases of temperature and:salinity in the western M
editerranean Sea are caused both by changes in atmospheric conditions
as described by the NAO-index and by the regulation of Spanish rivers.