That would be the 2nd layer, the stratosphere layer with the ozone at top.
The stratosphere which contains most of the atmosphere's ozone.
Thunderstorms form in the troposphere. The tops of strong thunderstorms may go into the stratosphere.
A cumulus cloud typically has a flat bottom and a puffy top. These clouds form due to rising air currents and are often associated with fair weather.
Cumulonimbus is the largest type of cloud. It is the only cloud that is tall enough to occupy low, medium and high heights. It is also the only (weather related) cloud that can form hail and lightning. Lightning can also be created in volcanic ash clouds, but they are not a weather related cloud.
Cumulonimbus clouds are the tallest clouds in the sky, reaching well into the troposphere.
Troposphere only
in any altitude in the troposphere. :)
Cirrus clouds are the highest clouds in the troposphere and are typically found at altitudes above 20,000 feet. They are thin, wispy clouds composed of ice crystals and are often a sign of fair weather when they are isolated.
The Cumulonimbus cloud develops in the lower part of the troposphere, near the Earth's surface, and can reach high into the troposphere. This cloud can be a sign of dangerous storms to come.
Troposphere is the layer closest to earth. All the cloud formation happens in troposphere only.
Cirrus clouds are commonly found at the top of the troposphere. They are thin and wispy in appearance, formed by ice crystals and often indicate fair weather or the approach of a change in the weather.
It is very cold up there, and water droplets freeze into ice.
This cloud is located in the middle altitude category, known as an altostratus cloud. Altostratus clouds typically form between 2 to 6 kilometers above the ground.
The top portion of the troposphere is known as the tropopause. It is characterized by a stable temperature gradient and acts as a boundary between the troposphere and the stratosphere above.
The higher you get in the troposphere, the colder it gets. However, when you reach the stratosphere the temperature starts to increase. A warm parcel of air rising creates a cumulus cloud, and eventually turns into a cumulonimbus cloud, which is a rain/snow cloud. As the warm updraft relies on colder surrounding air for it to be buoyant, as it gets warmer again it is no longer buoyant and begins to flatten out at the base of the stratosphere, unable to rise any further. Evidence of this is shown at the top of the cloud, which appears flattened like a pancake or appearing like an anvil. So it is this increase of temperature in the stratosphere which keeps rain and snow restricted to the troposphere.
A cirrus cloud is a high-altitude cloud that forms in the troposphere. It is composed of ice crystals and has a wispy, feathery appearance. Cirrus clouds often indicate fair weather but can also precede a change in the weather.