Atmospheric chemistry

Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth's atmosphere and that of other planets is studied. It is a multidisciplinary field of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines. Research is increasingly connected with other areas of study such as climatology.

The composition and chemistry of the atmosphere is of importance for several reasons, but primarily because of the interactions between the atmosphere and living organisms. The composition of the Earth's atmosphere changes as result of natural processes such as volcano emissions, lightning and bombardment by solar particles from corona. It has also been changed by human activity and some of these changes are harmful to human health, crops and ecosystems. Examples of problems which have been addressed by atmospheric chemistry include acid rain, ozone depletion, photochemical smog, greenhouse gases and global warming. Atmospheric chemists seek to understand the causes of these problems, and by obtaining a theoretical understanding of them, allow possible solutions to be tested and the effects of changes in government policy evaluated.

GCE Ordinary Level

The O Level (Ordinary Level) is a subject-based qualification conferred as part of the General Certificate of Education. It was introduced as part of British educational reform in the 1950s alongside the more in-depth and academically rigorous A-level (official title of qualification: General Certificate of Education - Advanced Level) in England, Wales and Northern Ireland. Those three jurisdictions replaced O Levels gradually with General Certificate of Secondary Education (GCSE) and International General Certificate of Secondary Education exams over time. The Scottish equivalent was the O-grade (replaced by the Standard Grade). The O Level qualification is still awarded by CIE Cambridge International Examinations, the international counterpart of the British examination Board OCR (Oxford, Cambridge & Royal Society of Arts), in select locations, instead of or alongside the International General Certificate of Secondary Education qualifications. Both CIE and OCR have Cambridge Assessment as their parent organisation. The Cambridge O Level has already been phased out, however, and is no longer available in certain administrative regions.