In late 2014, we collected the longest cores CHB14-2A and 2B, reaching down to 278.58 and 266.38 m depth, respectively18. For this reason, the analysis is limited to the 9–3 kyr BP time interval, which does not show major fluctuations in the spacing of the data points, including gaps9,29. We compare the Chew Bahir data with simulated precipitation from a transient climate model simulation of Holocene covering 10–0 kyr BP15. We use the window size w = 50 and the step size ws = 5 data points of the moving window to calculate the RQA measures. Second, we fitted a sigmoid function with four parameters a, b, c, and d$${x}_{{{{{{\rm{fit}}}}}}}(t)=a+\frac{{{{{{\rm{b}}}}}}}{1+{{{{{{\rm{e}}}}}}}^{-{{{{{\rm{d}}}}}}({{{{{\rm{t}}}}}}-{{{{{\rm{c}}}}}})}},\, {{{{{\rm{for}}}}}}-\infty \, < \, t \, < +\infty$$ (1)to the records \({x}_{i}\) with \(1 \, < \, i \, < \, n\) and n data points using nonlinear least-squares fitting.

Source: The North Africa Journal May 07, 2024 10:02 UTC