 |
| Titel |
Calcium isotopic composition of high-latitude proxy carrier Neogloboquadrina pachyderma (sin.) |
| VerfasserIn |
D. Hippler, R. Kozdon, K. F. Darling, A. Eisenhauer, T. F. Nägler |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 6, no. 1 ; Nr. 6, no. 1 (2009-01-05), S.1-14 |
| Datensatznummer |
250003310
|
| Publikation (Nr.) |
 copernicus.org/bg-6-1-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| The accurate reconstruction of sea surface temperature (SST) history in
climate-sensitive regions (e.g. tropical and polar oceans) became a
challenging task in palaeoceanographic research. Biogenic shell carbonate
SST proxies successfully developed for tropical regions often fail in cool
water environments. Their major regional shortcomings and the cryptic
diversity now found within the major high latitude proxy carrier
Neogloboquadrina pachyderma (sin.) highlight an urgent need to explore complementary SST proxies for
these cool-water regions. Here we incorporate the genetic component into a
calibration study of a new SST proxy for the high latitudes. We found that
the calcium isotopic composition (δ44/40Ca) of calcite from
genotyped net catches and core-top samples of the planktonic foraminifera
Neogloboquadrina pachyderma (sin.) is related to temperature and unaffected by genetic variations. The
temperature sensitivity has been found to be 0.17 (±0.02)‰ per 1°C,
highlighting its potential for downcore applications in open marine
cool-water environments. Our results further indicate that in extreme polar
environments, below a critical threshold temperature of 2.0 (±0.5)°C
associated with salinities below 33.0 (±0.5)‰, a prominent shift in
biomineralization affects the δ44/40Ca of genotyped and
core-top N. pachyderma (sin.), becoming insensitive to temperature. These findings
highlight the need of more systematic calibration studies on single
planktonic foraminiferal species in order to unravel species-specific
factors influencing the temperature sensitivity of Ca isotope fractionation
and to validate the proxies' applicability. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|