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Andrew R. Bowie Eric P. Achterberg Peter L. Croot Hein J.W. de Baar Patrick Laan James W. Moffett Simon Ussher Paul J. Worsfold 《Marine Chemistry》2006
The first large-scale international intercomparison of analytical methods for the determination of dissolved iron in seawater was carried out between October 2000 and December 2002. The exercise was conducted as a rigorously “blind” comparison of 7 analytical techniques by 24 international laboratories. The comparison was based on a large volume (700 L), filtered surface seawater sample collected from the South Atlantic Ocean (the “IRONAGES” sample), which was acidified, mixed and bottled at sea. Two 1-L sample bottles were sent to each participant. Integrity and blindness were achieved by having the experiment designed and carried out by a small team, and overseen by an independent data manager. Storage, homogeneity and time-series stability experiments conducted over 2.5 years showed that inter-bottle variability of the IRONAGES sample was good (< 7%), although there was a decrease in iron concentration in the bottles over time (0.8–0.5 nM) before a stable value was observed. This raises questions over the suitability of sample acidification and storage. 相似文献
23.
A 120 m thick section of the Cozy Dell Formation (middle Eocene), southem California, consists of a graylaminated mudstone and a tanungraded mudstone; sandstone beds are associated with the laminated mudstone. Sedimentary structures, stratification sequences, foraminiferal
distributions, and composition indicate that the ungraded mudstone is an upper slope hemipelagic deposit, while the laminated
mudstone is an overbank deposit associated with shallow channels or gullies in which the sandstone beds were deposited. This
depositional setting may be analogous to that of the modern Mississippi River delta front. 相似文献
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NPZ Models of Plankton Dynamics: Their Construction, Coupling to Physics, and Application 总被引:9,自引:0,他引:9
Peter J. S. Franks 《Journal of Oceanography》2002,58(2):379-387
Nutrient-phytoplankton-zooplankton (NPZ) models have been in use in oceanography for at least three decades, and are still
a common research tool. Given the discoveries of the last two decades, particularly concerning the role of bacteria in the
plankton, there are questions as to whether NPZ models can still be supported as a useful tool in planktonic research. Here
I review the construction of NPZ models, and some of the physical platforms they have been coupled to. I then discuss the
applications of NPZ-physical models, and conclude that they still constitute an important and viable research tool, provided
that the questions being explored are clearly stated.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
30.
Observations of the Labrador Sea eddy field 总被引:2,自引:0,他引:2
Jonathan M. Lilly Peter B. RhinesFriedrich Schott Kara LavenderJohn Lazier Uwe SendEric D’Asaro 《Progress in Oceanography》2003,59(1):75-176
This paper is an observational study of small-scale coherent eddies in the Labrador Sea, a region of dense water formation thought to be of considerable importance to the North Atlantic overturning circulation. Numerical studies of deep convection emphasize coherent eddies as a mechanism for the lateral transport of heat, yet their small size has hindered observational progress. A large part of this paper is therefore devoted to developing new methods for identifying and describing coherent eddies in two observational platforms, current meter moorings and satellite altimetry. Details of the current and water mass structure of individual eddy events, as they are swept past by an advecting flow, can then be extracted from the mooring data. A transition is seen during mid-1997, with long-lived boundary current eddies dominating the central Labrador Sea year-round after this time, and convectively formed eddies similar to those seen in deep convection modeling studies apparent prior to this time. The TOPEX / Poseidon altimeter covers the Labrador Sea with a loose “net” of observations, through which coherent eddies can seem to appear and disappear. By concentrating on locating and describing anomalous events in individual altimeter tracks, a portrait of the spatial and temporal variability of the underlying eddy field can be constructed. The altimeter results reveal an annual “pulsation” of energy and of coherent eddies originating during the late fall at a particular location in the boundary current, pinpointing the time and place of the boundary current-type eddy formation. The interannual variability seen at the mooring is reproduced, but the mooring site is found to be within a localized region of greatly enhanced eddy activity. Notably lacking in both the annual cycle and interannual variability is a clear relationship between the eddies or eddy energy and the intensity of wintertime cooling. These eddy observations, as well as hydrographic evidence, suggest an active role for boundary current dynamics in shaping the energetics and water mass properties of the interior region. 相似文献