Bachelor Thesis Defense by Jakob Skyggebjerg Kjær

Title: Scaling properties of CO2-proxy data in the Cenozoic

In order to understand complex systems behavior, scaling analysis is a frequent used tool from economics over biology to physical science. In an effort to better understand the Earth system’s feedback mechanisms and natural climate variability, the scaling properties of [CO2] (atmospheric CO2 content), [CO2]-proxy and temperature proxy data have been investigated from the scale of years to that of the Cenozoic with Power Spectra and Detrended Fluctuation Analysis. Repeating the analysis from [21, Ditlevsen and Shao, 2016], the scaling exponent of the latter technique show a scaling (Hurst) exponent of H ∼ 0.7 on meteorological temperature data and a much larger H ∼ 1.2 on glacial temperature records from the last 800.000 years. But it doesn’t show the same scaling break going from glacial to geological time, where H ∼ 1.06 − 1.19 when this analysis is applied to the geological temperature proxy of benthic δ18O‰ - and thus not the characteristic value of trivial white noise of H ∼ 0.5.

Supervisors: Peter Ditlevsen og Tais Dahl

 Censor: Jens Olaf Pepke Petersen