Publication Date:
2015-01-30
Description:
Particles determine the residence time of many dissolved elements in seawater. Although a substantial
number of field studies were conducted in the framework of major oceanographic programs as GEOSECS
and JGOFS, knowledge about particle dynamics is still scarce. Moreover, the particulate trace metal
behavior remains largely unknown. The GEOSECS sampling strategy during the 1970s focused on large
sections across oceanic basins, where particles were collected by membrane filtration after Niskin bottle
sampling, biasing the sampling toward the small particle pool. Late in this period, the first in situ pumps
allowing large volume sampling were also developed. During the 1990s, JGOFS focused on the quantifi-
cation of the ‘‘exported carbon flux’’ and its seasonal variability in representative biogeochemical prov-
inces of the ocean, mostly using sediment trap deployments. Although scarce and discrete in time and
space, these pioneering studies allowed an understanding of the basic fate of marine particles. This
understanding improved considerably, especially when the analysis of oceanic tracers such as natural
radionuclides allowed the first quantification of processes such as dissolved-particle exchange and par-
ticle settling velocities. Because the GEOTRACES program emphasizes the importance of collecting, char-
acterizing and analyzing marine particles, this paper reflects our present understanding of the sources,
fate and sinks of oceanic particles at the early stages of the program.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf