Preprints
https://doi.org/10.5194/cp-2021-94
https://doi.org/10.5194/cp-2021-94
20 Jul 2021
 | 20 Jul 2021
Status: this discussion paper is a preprint. It has been under review for the journal Climate of the Past (CP). The manuscript was not accepted for further review after discussion.

A theory of glacial cycles: resolving Pleistocene puzzles

Hsien-Wang Ou

Abstract. Since the summer surface air temperature that regulates the ice margin is anchored on the sea surface temperature, we posit that the climate system constitutes the intermediary of the orbital forcing of the glacial cycles. As such, the relevant forcing is the annual solar flux absorbed by the ocean, which naturally filters out the precession effect in early Pleistocene but mimics the Milankovitch insolation in late Pleistocene. For a coupled climate system that is inherent turbulent, we show that the ocean may be bistable with a cold state defined by the freezing point subpolar water, which would translate to ice bistates between a polar ice cap and an ice sheet extending to mid-latitudes, enabling large ice-volume signal regardless the forcing amplitude so long as the bistable thresholds are crossed. Such thresholds are set by the global convective flux, which would be lowered during the Pleistocene cooling, whose interplay with the ice-albedo feedback leads to transitions of the ice signal from that dominated by obliquity to the emerging precession cycles to the ice-age cycles paced by eccentricity. Through a single dynamical framework, the theory thus may resolve many long-standing puzzles of the glacial cycles.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Hsien-Wang Ou

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on cp-2021-94', Anonymous Referee #1, 25 Aug 2021
    • AC1: 'Reply on RC1', Hsien-Wang Ou, 31 Aug 2021
  • RC2: 'Comment on cp-2021-94', Anonymous Referee #2, 20 Sep 2021
  • AC8: 'Comment on cp-2021-94', Hsien-Wang Ou, 27 Sep 2021

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on cp-2021-94', Anonymous Referee #1, 25 Aug 2021
    • AC1: 'Reply on RC1', Hsien-Wang Ou, 31 Aug 2021
  • RC2: 'Comment on cp-2021-94', Anonymous Referee #2, 20 Sep 2021
  • AC8: 'Comment on cp-2021-94', Hsien-Wang Ou, 27 Sep 2021
Hsien-Wang Ou
Hsien-Wang Ou

Viewed

Total article views: 1,228 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
830 350 48 1,228 29 35
  • HTML: 830
  • PDF: 350
  • XML: 48
  • Total: 1,228
  • BibTeX: 29
  • EndNote: 35
Views and downloads (calculated since 20 Jul 2021)
Cumulative views and downloads (calculated since 20 Jul 2021)

Viewed (geographical distribution)

Total article views: 1,164 (including HTML, PDF, and XML) Thereof 1,164 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 29 May 2024
Download
Short summary
We present a theory of the glacial cycles for which the ocean constitutes the intermediary of the orbital forcing of the ice volume. We show that the ocean is bistable, so is the ice sheet, which thus allows large ice-volume signal when modulated forcing exceeds certain thresholds. Such thresholds are set by the global-mean convective flux, which is lowered during the Pleistocene cooling, so the model can explain the mid-Pleistocene transition and resolve many longstanding glacial puzzles.