Spring is two weeks early in Southern Finland. Ice and snow has melted, brooks and rivers are full of water, birds migrate north over the Gulf of Finland, and sunsets are beautiful reddish.
Red sunsets? They might please the eye, but also make my eyes itch when riding my bike. The red color is in fact caused by numerous air pollutants: small particles released from snow and spread all over by traffic, also from burning branches and trees. I'm waiting a heavy rain to wash the dust away.
(Aside: The Japanese flag represents the rising red sun, probably designed thousand years ago. Did the designer live in a village where people burned a lot of tree in wintertime? Did he or she understand our modern age will see in the flag a proof of air pollution?)
I'm slowly getting towards my point, data visualization, one of my key interests :)
Another thing, there are colored bands in the background to tell the air quality in words: good, satisfactory, so-so, bad, very bad. The bands for satisfactory and so-so are narrower than good and bad, while very bad is a much wider band than others. Why? Does that carry some message I should understand?
A probable explanation: The graphic designer gets exact figures of air pollutant concentrations every day. Color bands are concentration ranges defined by health care authorities. When drawing the chart, the designer hides exact numbers and adds color bands to correspond the good, satisfactory, so-so, etc air quality ranges.
But we humans don't think like this!