The following article was written by Jess Johnsrud, the Education Coordinator at the Woodland Dunes Nature Center.
I enjoy gentle spring thunderstorms. The sound of distant thunder and the pattering of the rain on the roof feel like an invitation to snuggle up with a good book. I also welcome the earthy, dewy smell that comes with those first few thunderstorms of the year.
That wonderful spring smell was studied by Austrian scientists in the 1960s and they named it petrichor. The smell is a result of a chemical reaction that occurs when rain falls on dry soil. During dry periods when resources are lacking, plants secrete oils that communicate to their roots to slow their growth and stop seed germination. When rain finally makes contact with the soil, the oils are released into the air. Additionally, some bacteria found in the soil produce something called geosmin. This is another naturally occurring organic compound that contributes to the musty aroma.
Spring thunderstorms may please the senses, but they also play an important role in cycling nitrogen. Lightning acts creates fertilizer because it breaks down nitrogen molecules in the atmosphere. Lightning is five times hotter than the surface of the sun and as it spreads through the atmosphere, it breaks apart molecules of nitrogen. Single nitrogen molecules often bond with oxygen molecules, and this creates nitrate. Nitrate dissolves in water molecules found in the clouds above, then falls to the ground in the form of rain. Plants take up this natural, free fertilizer through their roots as it is an important nutrient for plant growth and development.
I was astonished to learn that on planet Earth, there are about 40 lighting strikes a second, which is more than 3 million strikes each day. This massive amount of energy creates about 13,000 tons of nitrate!
Next time there’s a thunderstorm, take some time to enjoy the sounds and maybe even the smell. Then take a moment to appreciate the tremendous service that lightning provides for our planet. Nature is amazing!
