Late Pliocene-early Pleistocene 100-ka problem
Abstract
Little is known about the 100-ka ice volume cycles immediately before 1 Ma except that they are coherent with the 100-ka eccentricity cycles. Here we show that ice volume and ocean circulation change/global carbon mass balance are phase-locked and highly coupled regarding amplitude envelopes at the 100-ka band, but neither is phase-locked to and amplitude-coupled to the 100-ka eccentricity orbital forcing signal between 3-1 Ma. We describe this phasing and amplitude mismatch at the 100-ka band between 3-1 Ma between eccentricity forcing and paleo-ice volume records as the ``late Pliocene-early Pleistocene 100-ka problem.'' A free 100-ka oscillation internal to our climate system, especially those related to oscillations of atmospheric CO2 concentration, operating on an Earth characterized by a high-inertia deep thermohaline ocean that can store carbon and heat, might hold the key for the ``late Pliocene-early Pleistocene 100-ka problem.''
- Publication:
-
Geophysical Research Letters
- Pub Date:
- November 2008
- DOI:
- 10.1029/2008GL035265
- Bibcode:
- 2008GeoRL..3521606N
- Keywords:
-
- Global Change: Climate dynamics (0429;
- 3309);
- Paleoceanography: Astronomical forcing;
- Paleoceanography: Glacial;
- Paleoceanography: Insolation forcing;
- Paleoceanography: Micropaleontology (0459;
- 3030)