Sentences with phrase «known cyclic variations»
There was a drop during the Ice Ages to about 180 ppm, driven by a complex of processes, with known cyclic variations in the earth's orbit at the root, with the recovery due to natural processes.
https://dotearth.blogs.nytimes.com/ Not exact matches
The team's data also hint that the star's cyclic 4 - day variation in brightness, although still weak, is once again growing more robust — but no one knows what's driving these flutterings or how long they will last.
Arctic ice periods caused by cyclic variations in ocean currents have been known for ages, too.