# What exactly is delta-14C and why are there periodic plateaus in the delta-14C curve?

I downloaded the IntCal13, IntCal09, and IntCal04 datasets (parent site), and when I plotted the last 24k years was surprised to see a plateau or even reversal appear every ~5300 years. Apparently we are near the end of one of these periods now:

Two questions:

1. Is there any term for these periods during which the trend flattens or even reverses?
2. I may be missing something basic about what the delta-14C values represent, basically I thought it was the same equation used here. Is that correct?

Edit:

I came back to this as a reference and found that unfortunately radiocarbon.org seems to be down. There is a new site here, but the data is all still hosted at the radiocarbon.org domain...

• How is 14C made on Earth? What might influence that process? – Jon Custer Mar 20 '19 at 13:02
• @JonCuster You can see I tagged this with sun, cosmic rays, and geophysics (closest to geomagnetism I saw). Besides an increase in 14C production, such net 14C increases could also be due to less "old" carbon being released from oceans/etc. However, my question is about whether someone has attached significance to this periodicity and what specifically they have proposed is happening every ~5k years. – Livid Mar 20 '19 at 13:37
• the half life of C14 is 5730 years. I wonder if what we see if this this break down? – Rick Apr 2 '19 at 23:26
• @Rick That is an interesting point. I am not sure what to make of it though. – Livid Apr 3 '19 at 2:25
• You could try multiplying by data by $2^{t/\lambda}$ to get rid of the exponential decay ($\lambda$ is the half-life) and then take the Fourier transform to see what those periodic components look like. – Ryan Thorngren Apr 6 '19 at 7:48