Open AccessOcean biology could control atmospheric δ 13 C during glacial‐interglacial cycle
Author(s) -
Brovkin Victor,
Hofmann Matthias,
Bendtsen Jørgen,
Ganopolski Andrey
Publication year - 2002
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2001gc000270
Subject(s) - glacial period , interglacial , biosphere , ice core , carbon cycle , deglaciation , last glacial maximum , geology , atmospheric sciences , oceanography , carbon dioxide in earth's atmosphere , isotopes of carbon , environmental science , climate change , paleontology , ecology , total organic carbon , environmental chemistry , chemistry , ecosystem , biology
Estimates of changes in the global carbon budget are often based on the assumption that the terrestrial biosphere controls the isotopic composition of atmospheric CO 2 since terrestrial plants discriminate against the 13 C isotope during photosynthesis. However, this method disregards the influence of 13 C fractionation by the marine biota. Here an interpretation of the glacial‐interglacial shifts in the atmospheric CO 2 concentration and δ 13 CO 2 measured in the Taylor Dome ice core [ Smith et al. , 1999] is given by accounting for possible changes in the ocean biology based on sensitivity simulations undertaken with the intermediate complexity model CLIMBER‐2. With a combined scenario of enhanced biological and solubility pumps, the model simulates glacial atmospheric CO 2 and δ 13 CO 2 similar to those inferred from the ice core. The simulations reveal that a strengthening of the oceanic biological carbon pump considerably affects the atmospheric δ 13 CO 2 .