what is the peculiar smell in the air before/during rain when it has not rained for a while?

Answer 1

i know what you mean. It is common where I grew up - Phoenix and Tucson. It is the dust that the first drops of rain kick up which is carried by the wind gusts. I really miss it. It was such a relaxing smell. I would enjoy watching the storms come across the valley, and the lightening. The smell is special. I believe that old timers - during the dust bowl era - could tell where the wind was blowing from by the smell of the dust.

;-D It rains a lot in China. The dust here is mostly black, from car tires and exhaust. The smell is not good. Thanks for the memory!

Answer 2

Before rain the earth is very hot and the air which is full of nitrogen is everywhere along with pollutants like CO etc thus what you smell is all the many and minute chemical reactions and after the rain the many chemical reactions further is given a kick by water. You can check the nitrogen cycle and see its structure before and after rain, even at lightening!!!

Answer 3

I don't know where these people heard that the smell after rain is ozone, or that ozone formed during a rainstorm, but unless they are linking to websites that detail that information, I would highly doubt it.

Tropospheric ozone (ozone near the surface that is hazardous to health) is the product of chemical reactions. There are several series of chemical reactions that produce ozone. One is:
NO + O3 --> NO2+ O2
NO2 + light --> NO + O
O + O2 + m --> O3 + m (where m is any molecule; it is unchanged during the reaction.)

However most reactions that produce ozone are initiated by a hydroxyl radical (OH). Hydroxyl radicals are formed in the process:
O3 + sunlight (wavelength < 310nm) --> O2 + O*
O* + H2O --> OH* + OH*
(where * indicates an excited chemical state)
Because this is the most common way to create hydroxyl radicals, they are found in higher levels in sunny, polluted areas.

These hydroxyl radicals will then react with volatile organic compounds (VOCs) to form multiple ozone molecules.

As you can probably see, sunlight is a major component in the production of ozone, and you can see a direct link in ozone levels and the time of day. ( http://www.tceq.state.tx.us/cgi-bin/compliance/monops/daily_summary?cams=81 ) You will notice that ozone levels peak in the afternoon and decrease to 0 at night.

Thunderstorms, as they obscure the sun, would greatly inhibit the production of tropospheric ozone. The smell of rain is caused by a number of things. One is just clean air. Each raindrop requires a solid particle to form on, and as it falls from the sky, it collects even more dirt that is usually in the air. Another is caused by bacteria in the ground that produce spores that are kicked up during a rainstorm.

Also, due to chemicals in the air, rainwater is usually acidic, and reacts with minerals in the ground or with oils released by trees and plants.

Answer 4

I believe it is ionized particles that are released by the rain drops. The reason they accumulate between long dry spells is from the sun's radiation beating down on surfaces without being washed off.

This is a real phenomena I remember reading about very long ago.

It makes sense because the effect is much stronger both in desert areas and after droughts than in areas that get more rain.

Answer 5

The smell of rain is caused by ozone (O3). It is commonly produced through dissociation of molecular oxygen (02) into two unstable atomic oxygens (2 O), each of which then recombine with molecular oxygen to make ozone.

This dissociation can occur either by high-voltage electrical discharge or by bombardment with ultraviolet light. The high voltages which occur in thunderstorms create ozone within the cloud (even when lightning is not actively occuring), and this ozone is carried toward the ground by the downdraft in the thundercloud and blown out ahead of the storm, where you smell it and can tell rain is coming.

Answer 6

I rather have lived in West Virginia maximum of my existence, and we've extremely some rain at cases. specific, I do love the scent after wards. i'm a us of a boy at coronary heart, and that i spent some nights watching the sunlight arise interior the woods. i think of that obtaining remote from synthetic smells that flood the close by large industry and smelling undergo **** interior the woods makes me happy that we invented Lysol Spray..... LMAO

Answer 7

Carbon dioxide in the atmosphere is disolved in the raindrops as they fall to form a weak solution of carbonic acid. This could be the cause of the resulting odour. I do not think it is ozone.

Answer 8

It could be ozone. THis is a special molecule of oxygen . It has 3 oxgyen atoms that occurs when regular oxygen which has 2 atoms is zapped by lightning>

Answer 9

Air becomes electricly charged and produces ozone. Its the ozone you smell.

Answer 10

It's the smell of all that water in the air finally coalescing and cooling down, what you smell is much like...a lake...it's just water.