Glossary 337Millibar (mb) Unit of atmospheric pressure equal tohectopascal.Typical
pressure at the surface is 1000 mb
MINK Region of the United States comprising the states of Missouri, Iowa,
Nebraska and Kansas, used for a detailed climate study by the US Department
of Energy
Mole Fraction (or mixing ratio) The ratio of the number of moles of a constituent
in a given volume to the total number of moles of all constituents in that
volume. It differs from volume mixing ratio (expressed for instance in ppmv
etc.), by the corrections for non ideality of gases – that is significant relative to
measurement precision for many greenhouse gases
Molecule Two or moreatomsof one or moreelementschemically combined in
fixed proportions. For example, atoms of the elements carbon (C) and oxygen
(O) are chemically bonded in the proportion one to two to makemoleculesof
the compoundcarbon dioxide(CO 2 ). Molecules can also be formed of a single
element, for example ozone (O 3 )
Monsoon Particular seasonal weather patterns in sub-tropical regions which are
connected with particular periods of heavy rainfall
Neutron A component of most atomic nuclei without electric charge, of
approximately the same mass as theproton
OECD Organization for Economic Cooperation and Development; a consortium
of thirty countries (including the members of the European Union, Australia,
Canada, Japan and the USA) that share commitment to democratic government
and market economy
Ozone hole A region of theatmosphereover Antarctica where, during spring in
the southern hemisphere, about half the atmospheric ozone disappears
Paleoclimatology The reconstruction of ancientclimatesby such means as
ice-core measurements. These use the ratios of differentisotopesof oxygen in
different samples taken from a deep ice ‘core’ to determine the temperature in
theatmospherewhen the samplecondensedas snow in the clouds. The deeper
the origin of the sample, the longer ago the snow became ice (compressed
under the weight of more snowfall)
Parameterisation In climate models, this term refers to the technique of
representing processes in terms of an algorithm (a process of step by step
calculation) and appropriate quantities (or parameters)
Passive solar design The design of buildings to maximize use ofsolar radiation.
A wall designed as a passive solar energy collector is called a solar wall
Photosynthesis The series of chemical reactions by which plants take in the sun’s
energy,carbon dioxideand water vapour to form materials for growth, and give
out oxygen. Anaerobic photosynthesis takes place in the absence of oxygen
Phytoplankton Minute forms of plant life in the oceans
ppb parts per billion (thousand million) – measurement of mixing ratio(seemole
fraction) or concentration
ppm parts per million – measurement of mixing ratio (seemole fraction)or
concentration
Precautionary Principle The principle of prevention being better than cure,
applied to potential environmental degradation