Preprints
https://doi.org/10.5194/egusphere-2023-1858
https://doi.org/10.5194/egusphere-2023-1858
05 Sep 2023
 | 05 Sep 2023

Geographic variability of dust and temperature in climate scaling regimes over the Last Glacial Cycle

Nicolás Acuña Reyes, Elwin van ’t Wout, Fabrice Lambert, and Shaun Lovejoy

Abstract. Temperature and mineral dust records serve as valuable paleoclimate indicators for studying atmospheric variability across a wide range of temporal scales. Due to the typically lower resolution of older sections within these records, studies investigating the geographical variability of the atmosphere have predominantly focused on periods shorter than one glacial cycle, such as the Holocene or the Last Glacial Maximum. In this study, we utilise a Haar-based algorithm to evaluate the geographic variability of dust and temperature records throughout the last glacial cycle. This algorithm enables us to analyse non-equidistant sampling series, allowing for the utilisation of both high and low-frequency information from the records. Consequently, we can investigate timescales ranging from decades to thousands of years. Notably, our findings indicate that the transition from macroweather to climate regimes occurs at shorter timescales in polar regions compared to the tropics or mid-latitudes. Furthermore, disparities between the dust records of the North and South Poles were observed. Finally, we assess the time-dependent correlation between the polar regions and the lower latitudes. Our analysis reveals high correlations at timescales of approximately 20, 40, and 100 kyr, which aligns with the Milankovitch cycles. Conversely, all sites exhibit a loss of correlation between 40 and 80 kyr, indicating the absence of an identifiable oscillation synchronisation mechanism at these scales. On the one hand, our findings support the use of the Haar-based method as an alternative for analysing nonuniform datasets. On the other hand, they underscore the necessity for additional high-resolution or longer time series data from the tropics or mid-latitudes, as the currently available data fail to adequately represent the glacial-interglacial cycles.

Nicolás Acuña Reyes, Elwin van ’t Wout, Fabrice Lambert, and Shaun Lovejoy

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Review by Anders Svensson', Anders Svensson, 11 Oct 2023
    • AC1: 'Reply on RC3', Nicolás Acuña Reyes, 05 Jan 2024
  • RC2: 'Comment on egusphere-2023-1858', Anonymous Referee #2, 24 Oct 2023
    • AC1: 'Reply on RC3', Nicolás Acuña Reyes, 05 Jan 2024
  • RC3: 'Comment on egusphere-2023-1858', Anonymous Referee #3, 14 Nov 2023
    • AC1: 'Reply on RC3', Nicolás Acuña Reyes, 05 Jan 2024
Nicolás Acuña Reyes, Elwin van ’t Wout, Fabrice Lambert, and Shaun Lovejoy
Nicolás Acuña Reyes, Elwin van ’t Wout, Fabrice Lambert, and Shaun Lovejoy

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Short summary
This study analyzes temperature and mineral dust records to understand past climate changes, using a Haar-based algorithm. It reveals faster shifts from macro-weather to climate regimes in polar regions than the tropics, with North-South Pole dust record discrepancies. High cross-Haar correlation coefficient between sites shows global synchronization with Milankovitch cycles, yet a drop in correlation highlighting the lack of global synchronising forcing in the Δt = 40 to 80 kyr range.