Dust-Induced Destabilization of Glacial Climates

TL;DR

This paper proposes a theory that atmospheric dust feedbacks with the hydrological cycle to explain abrupt, stochastic climate transitions during glacial periods, supported by radiative-convective modeling and stochastic analysis.

Contribution

It introduces a novel dust-hydrology feedback mechanism as a driver for glacial climate abrupt transitions, supported by theoretical modeling.

Findings

Dust feedbacks can induce climate bistability.

The model reproduces observed abrupt transitions.

The mechanism links dust, radiation, and precipitation feedbacks.

Abstract

The climate record preserved in polar glaciers, mountain glaciers, and widespread cave deposits shows repeated occurrence of abrupt global transitions between cold/dry stadial and warm/wet interstadial states during glacial periods. These abrupt transitions occur on millennial time scale and in the absence of any known global-scale forcing. Here a theory is advanced implicating a feedback between atmospheric dust and the hydrological cycle in producing these abrupt transitions. Calculations are performed using a radiative-convective model that includes the interaction of aerosols with radiation to reveal the mechanism of the dust/precipitation interaction feedback process and a Langevin equation is used to model glacial climate destabilization by this mechanism. This theory explains the observed bimodal, stochastic, and abrupt nature of the transitions as well as their intrinsic connection with the hydrological cycle.