The role of stochastic noise in the abrupt climatic transitions of the pleistocene

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6246986

Matteucci, G

Analyses of marine [delta][sup 18]O records suggest that the variations of the Earth's orbital parameters have induced and provided the timing of the Pleistocene climatic oscillations. This dissertation analyses some statistical properties of the Pleistocene climate by estimating the Probability Density Function (PDF) of the [delta][sup 18]O record. The results allow to define statistically what were the [open quotes]typical conditions[close quotes] (in a probabilistic sense) of the Quaternary, to identify the modes of the PDF as the mean glacial and interglacial climatic states, and to clarify the meaning and the abruptness of the climatic transitions. A zero-dimensional Energy Balance Model is developed. The nonlinearity of the ice albedo-temperature feedback leads to multiple steady-state equilibria. The role of stochastic perturbations and their interaction with the orbital forcing in producing the periodic and abrupt climatic transitions of the late Pleistocene are illustrated. A stochastic sensitivity analysis is used to clarify the results, especially the selective amplification of the orbitally-induced 100 kyr cycle, and the predictability of the system on the time scales of the orbital cycles. From the analysis of GCM simulations and observational zonally- averaged data a one-dimensional EBM is then developed. The strong nonlinearity of this model and the occurrence of multiple equilibria is caused by the presence of the Thin Ice Cap Instability. A discussion of the features that stochastic perturbations would introduce, follows. Finally a GCM sensitivity study to atmospheric CO[sub 2] shows how the effects of varying CO[sub 2] concentrations can be included in simple EBMs. The role that stochastic perturbations, orbital forcing, and the known past concentrations of atmospheric CO[sub 2] have played in producing the abrupt climatic transitions of the late Pleistocene is discussed.

• Research Organization: Yale Univ., New Haven, CT (United States)
• OSTI ID: 6246986
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CENOZOIC ERA
CHALCOGENIDES
CLIMATES
CLIMATIC CHANGE
ECOLOGICAL CONCENTRATION
ENERGY BALANCE
GENERAL CIRCULATION MODELS
GEOLOGIC AGES
MATHEMATICAL MODELS
OSCILLATIONS
OXIDES
OXYGEN COMPOUNDS
PALEOCLIMATOLOGY
PALEONTOLOGY
PLEISTOCENE EPOCH
QUATERNARY PERIOD
SENSITIVITY ANALYSIS
VARIATIONS