Development of Modular Ontologies in Casl

Alien Invasive Species and Int'l Trade

Klaus Lu¨ttich1 ; Claudio Masolo2 ; Stefano Borgo2 ; 2 Laboratory for Applied Ontology, ISTC-CNR, Trento, Italy

Others  :  http://CEUR-WS.org/Vol-232/paper5.pdf
PID  :  639

来源: CEUR

【 摘 要 】

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 1970鈥檚 focused on large sections across oceanic basins, where particles were collected by membrane filtration after Niskin bottle sampling, biasing the sampling towards the small particle pool. Late in this period, the first in situ pumps allowing large volume sampling were also developed. During the 1990鈥檚, JGOFS focused on the quantification of the 鈥渆xported carbon flux鈥?and its seasonal variability in representative biogeochemical provinces 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 particle settling velocities. Because the GEOTRACES program emphasizes the importance of collecting, characterizing and 39 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.