STRATOSPHERE

(Ozone)

Stratosphere, layer of Earth’s atmosphere lying between the troposphere and the mesosphere.

The stratosphere  is the second major layer of Earth’s atmosphere, just above the troposphere, and below the mesosphere. The stratosphere is stratified (layered) in temperature, with warmer layers higher and cooler layers closer to the Earth; this increase of temperature with altitude is a result of the absorption of the Sun’s ultraviolet radiation (shortened UV) by the ozone layer. 

This is in contrast to the troposphere, near the Earth’s surface, where temperature decreases with altitude. The border between the troposphere and stratosphere, the tropopause, marks where this temperature inversion begins.

Near the equator, the lower edge of the stratosphere is as high as 20 km (66,000 ft; 12 mi), at midlatitudes around 10 km (33,000 ft; 6.2 mi), and at the poles about 7 km (23,000 ft;4.3 mi) Temperatures range from an average of −51 °C (−60 °F; 220 K) near the tropopause to an average of −15 °C (5.0 °F; 260 K) near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter).

Winds in the stratosphere can far exceed those in the troposphere, reaching near 60 m/s (220 km/h; 130 mph) in the Southern polar vortex

The lower portion of the stratosphere is nearly isothermal (a layer of constant temperature), whereas temperatures in its upper levels increase with altitude. The stratosphere extends from the tropopause at about 10 to 17 km (about 6 to 11 miles) altitude to its upper boundary (the stratopause) at about 50 km (30 miles), and it also contains the ozone layer. 

OZONE LAYER

Ozone layer, also called ozonosphere, region of the upper atmosphere, between roughly 15 and 35 km (9 and 22 miles) above Earth’s surface, containing relatively high concentrations of ozone molecules (O₃).

Approximately 90 percent of the atmosphere’s ozone occurs in the stratosphere, the region extending from 10–18 km (6–11 miles) to approximately 50 km (about 30 miles) above Earth’s surface. In the stratosphere the temperature of the atmosphere rises with increasing height, a phenomenon created by the absorption of solar radiation by the ozone layer.

The ozone layer effectively blocks almost all solar radiation of wavelengths less than 290 nanometers from reaching Earth’s surface, including certain types of ultraviolet (UV) and other forms of radiation that could injure or kill most living things.

Location of Ozone In Earth’s Atmosphere:

In the mid latitudes the peak concentrations of ozone occur at altitudes from 20 to 25 km (about 12 to 16 miles).

 Peak concentrations are found at altitudes from 26 to 28 km (about 16 to 17 miles) in the tropics and from about 12 to 20 km (about 7 to 12 miles) toward the poles. The lower height of the peak-concentration region in the high latitudes largely results from poleward and downward atmospheric transport processes that occur in the middle and high latitudes and the reduced height of the tropopause (the transition region between the troposphere and stratosphere).

Most of the remaining ozone occurs in the troposphere, the layer of the atmosphere that extends from Earth’s surface up to the stratosphere.

Near-surface ozone often results from interactions between certain pollutants (such as nitrogen oxides and volatile organic compounds), strong sunlight, and hot weather. It is one of the primary ingredients in photochemical smog, a phenomenon that plagues many urban and suburban areas around the world, especially during the summer months.