Historical Background

I recently read that in 2019, the Ozone Hole was one of the smallest on record. Peaking at only 9.3 million square miles in 2019, this is the smallest since the early 1980's. That's great news, but what is the Ozone Hole and why does it matter?

The Ozone Hols is a seasonal depletion of the Ozone Layer - a protective layer of the atmosphere that is vital in protecting the Earth from the bulk of the Sun's ultraviolet radiation. The hole forms in the Southern Hemisphere, over Antarctica, during the Southern Hemisphere Spring. Chemical reactions driven by Bromine and Chlorine (coming from CFC's) cause the rapid degredation of the Ozone layer, with the hole peaking in late September or early October.

Efforts have been in place since 1979 to monitor the size of the hole, but was actually discovered in the early 1900's when explorers noticed unusual clouds in the Antarctic Stratosphere. The British Antarctic Survey began measuring the amount of Ozone (in Dobson Units) beginning in 1956.

The Ozone is vital in protecting us from the harmful UV radiation that can lead to sunburns, skin cancer, cataracts and more health issues. Global legislation has been put in place to limit CFC emissions. The US enacted its first legislation aimed at limiting CFCs in 1978 - a year before NASA began monitoring the Ozone Hole. Check out this link from the EPA on how we're taking steps to protect the Ozone Layer.

Our data set this month looks at the size of the Ozone Hole from 1979 through 2019. This is an incredibly simple dataset, but could be made really interesting with some supplemental data... We'd really love to see what you can do with this month's dataset! Download the data and see what you can visualize. Create your viz and post your work to Tableau Public and Twitter with the hashtag #ThrowbackDataThursday, tagging @TThrowbackThurs. We'll feature community vizzes throughout the month!

Data Source

This month's data comes from the NASA Ozone Watch website. Please cite this source on your viz.