It’s often useful to be able to play around with things to get a feel for how they work. One of these is 1/f noise. There’s a very simple algorithm for generating this type of noise.
We set up n storage locations. To start a random value (-1 to 1) is stored in each location, Then every 2nd step, the first one changes to a new random value (-1 to +1), every 4th step the second changes, every 8th step the third, every 16th the fourth, etc. until the last one change in the middle of the run.
If we then set it so that at each step only one storage location is changing, then if we sum all the locations we have a random value that changes only by a random value between (-1 to +1) at each step.
For the equivalent of 10 years of daily readings we need ~4000 steps and when graphed for a scale of years we should have something like this: