|
|
|
|
|
| Galbraith, Eric D.; Kienast, Markus; Jaccard, Samuel L.; Pedersen, Thomas F.; Brunelle, Brigitte G.; Sigman, Daniel M.; Kiefer, Thorsten. |
| [1] The open subarctic Pacific is, at present, a high nitrate low chlorophyll (HNLC) region, where nitrate is perennially abundant at the surface. Theoretically, the HNLC status of this region is subject to modification by ocean circulation and/or micronutrient supply, with implications for the effectiveness of the biological pump and hence carbon sequestration in the ocean interior. Records of biogenic detritus in sediments from throughout the subarctic Pacific indicate that export production was generally lower during glacial maxima, while nitrogen isotope measurements from the Bering Sea have shown that nitrate consumption there was more complete during the last glacial period than it is today. Here, nitrogen isotopic analyses of bulk sediments (delta... |
| Tipo: Text |
|
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34840/33281.pdf |
| |
|
|
| Gebhardt, Holger; Sarnthein, Michael; Grootes, Pieter M.; Kiefer, Thorsten; Kuehn, Hartmut; Schmieder, Frank; Roehl, Ursula. |
| Our study addresses fundamental questions of the mode and timing of orbital and millennial-scale changes in the meridional overturning circulation (MOC) of the subarctic North Pacific. Particular concerns are the vertical mixing, the present and past abundance of nutrients in surface waters despite strong stratification, and the North Pacific-North Atlantic seesaw of oscillations in sea surface temperature (SST). We do this by generating and interpreting multiple records for glacial terminations I-V down two long piston cores, one each from the western and eastern subarctic Pacific. Chlorins and biogenic opal are proxies for surface water productivity; delta(13)C of epibenthic foraminifera is a record of deepwater ventilation; and the delta(13)C of N.... |
| Tipo: Text |
|
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00236/34772/33376.pdf |
| |
|
|
|
