After a lightning bolt, this gamma radiation dies down with a half-life of ten minutes, but these low-energy gamma rays go only about 90 metres through the air on average, so they may only be detected for a minute or so as the "cloud" of 13N and 15O floats by, carried by the wind.
Nitrogen-14 is one of the very few stable nuclides with both an odd number of protons and of neutrons (seven each) and is the only one to make up a majority of its element.
The original source of nitrogen-14 and nitrogen-15 in the Universe is believed to be stellar nucleosynthesis, where they are produced as part of the CNO cycle.
Some kinds of cosmic radiation cause a nuclear reaction with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a half-life of 5700(30) years.
It has a short half-life of about 7.1 s,[4] but its decay back to 16O produces high-energy gamma radiation (5 to 7 MeV).