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Definition of Terms Used Within the DDC Pages

Glossary N-O

Glossary of acronyms and specialised terms on the IPCC-DDC website.
The definitions shown here are from the IPCC Fifth Assessment Report (AR5) working group glossaries: WGI, WGII and WGIII. The source working group is indicated on each definition.

A | B | C | D | E | F-G | H-I | J-K | L-M | N-O | P-Q | R | S | T | U-V | W-Z

NASA

National Aeronautics and Space Administration

NCAR

National Centre for Atmospheric Research

NCAS

National Centre for Atmospheric Science

NCSP

National Communications Support Programme (UN)

NERC

National Environment Research Council

OECD

Organisation for Economic Co-operation and Development

Ozone

The triatomic form of oxygen (O3), a gaseous atmospheric constituent. In the troposphere, it is created both naturally and by photochemical reactions involving gases resulting from human activities (smog). Tropospheric ozone acts as a greenhouse gas. In the stratosphere, ozone is created by the interaction between solar ultraviolet radiation and molecular oxygen (O2). Stratospheric ozone plays a dominant role in the stratospheric radiative balance. Its concentration is highest in the ozone layer. WGI

Ozone Hole

See Ozone Layer

Ozone Layer

The stratosphere contains a layer in which the concentration of ozone is greatest, the so-called ozone layer. The layer extends from about 12 to 40 km above the Earth's surface. The ozone concentration reaches a maximum between about 20 and 25 km. This layer has been depleted by human emissions of chlorine and bromine compounds. Every year, during the Southern Hemisphere spring, a very strong depletion of the ozone layer takes place over the Antarctic, caused by anthropogenic chlorine and bromine compounds in combination with the specific meteorological conditions of that region. This phenomenon is called the ozone hole. WGI