Studies in the Modern Ocean

CTD/hydrocast package descending into the Southern Ocean. Photo Kenemy

The CTD/hydrocast package descending into the Southern Ocean water column from the deck of the South African research icebreaker S.A. Agulhas II, sailing from Cape Town to the Antarctic winter ice edge. Photo: Preston Cosslett Kemeny ’15

 

References

AuthorTitleTypeYear
6 Publications
Applied Filters: First Letter Of Last Name: J Reset
Two modes of change in Southern Ocean productivity over the past million years
S.L. Jaccard, C.T. Hayes, A. Martínez-García, D.A. Hodell, R.F. Anderson, D.M. Sigman, G.H. Haug
Export of organic carbon from surface waters of the Antarctic Zone of the Southern Ocean decreased during the last ice age, coinciding with declining atmospheric carbon dioxide (CO2) concentrations, signaling reduced exchange of CO2 between the ocean interior and the atmosphere. In contrast, in the Subantarctic Zone, export production increased…
A pervasive link between Antarctic ice core and subarctic Pacific sediment records over the past 800 kyrs
S.L. Jaccard, E.D. Galbraith, D.M. Sigman, G.H. Haug

Recently developed XRF core-scanning methods permit paleoceanographic reconstructions on timescales similar to those of ice-core records. We have investigated the distribution of biogenic barium (Ba/Al), opal and carbonate (Ca/Al) in a sediment core retrieved from the abyssal subarctic Pacific (ODP 882, 50°N, 167°E, 3244 m) over an interval…

Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool
S.L. Jaccard, E.D. Galbraith, D.M. Sigman, G.H. Haug, R. François, T.F. Pedersen, P. Dulski, H.R. Thierstein

Measurements of benthic foraminiferal cadmium:calcium (Cd/Ca) have indicated that the glacial-interglacial change in deep North Pacific phosphate (PO4) concentration was minimal, which has been taken by some workers as a sign that the biological pump did not store more carbon in the deep glacial ocean. Here we present sedimentary redox…

Glacial/interglacial changes in subarctic north pacific stratification
S.L. Jaccard, G.H. Haug, D.M. Sigman, T.F. Pedersen, H.R. Thierstein, U. Röhl

Since the first evidence of low algal productivity during ice ages in the Antarctic Zone of the Southern Ocean was discovered, there has been debate as to whether it was associated with increased polar ocean stratification or with sea-ice cover, shortening the productive season. The sediment concentration of biogenic barium at Ocean Drilling…

Variation of nitrate concentrations and δ15N values of Seawater in the Drake Passage, Antarctic Ocean
Y.H. Jang, B.-K. Khim, H.C. Shin, D.M. Sigman, Y. Wang, C.S. Hong
Seawater samples were collected at discrete depths from five stations across the polar front in the Drake Passage (Antarctic Ocean) by the 20th Korea Antarctic Research Program in December, 2006. Nitrate concentrations of seawater increase with depth within the photic zone above the depth of Upper Circumpolar Deep Water (UCDW). In contrast, δ15N…
Coral photosymbiosis on Mid-Devonian reefs
J. Jung, S. Zoppe, T. Söte, S. Moretti, Nicolas Duprey, A.D. Foreman, T. Wald, H.B. Vonhof, G.H. Haug, D.M. Sigman, A. Mulch, E. Schindler, D.J. Janssen, A. Martínez-García
The ability of stony corals to thrive in the oligotrophic (low-nutrient, low-productivity) surface waters of the tropical ocean is commonly attributed to their symbiotic relationship with photosynthetic dinoflagellates1,2. The evolutionary history of this symbiosis might clarify its organismal and environmental roles3, but its prevalence through…