High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles

Details High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles

Nov 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011e%26psl.311...69s&link_type=abstract

Earth and Planetary Science Letters, Volume 311, Issue 1, p. 69-81.

Other

Plankton Biogeography, Ocean Circulation, Ocean Biogeochemistry, Thermocline, Atlantic Ocean, Pleistocene

Scientific paper

One of the earliest discoveries in palaeoceanography was the observation in 1935 that the (sub)tropical planktic foraminifer Globorotalia menardii became absent or extremely rare in the Atlantic Ocean during glacials of the late Pleistocene. Yet a mechanistic explanation for G. menardii's extraordinary biogeographic behaviour has eluded palaeoceanographers for 75 years. Here we show that modern G. menardii, along with two other species that also suffer Atlantic population collapses during glacials, track poorly ventilated waters globally in their thermocline habitats. The ventilation states of low latitude thermoclines are 'set', to a first order, by intermediate water masses originating at high latitudes. In the modern Atlantic this control on low latitude thermocline ventilation is exerted by relatively poorly ventilated, southern-sourced Antarctic Intermediate Water (AAIW) and sub-Antarctic Mode Water (SAMW). We suggest that the glacial Atlantic foraminifer population collapses were a consequence of a low latitude thermocline that was better ventilated during glacials than it is today, in line with geochemical evidence, and driven primarily by a well-ventilated, northern-sourced intermediate water mass. A ventilation mechanism driving the glacial population collapses is further supported by our new constraints on the precise timing of these species' Atlantic proliferation during the last deglaciation — occurring in parallel with a wholesale, bipolar reorganisation of the Atlantic's thermocline-to-abyssal overturning circulation. Our findings demonstrate that a bipolar seesaw in the formation of high latitude intermediate waters has played an important role in regulating the population dynamics of thermocline-dwelling plankton at lower latitudes.

Affiliated with

Also associated with

No associations

Rating

High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1056145