"Albedo is the ratio of outgoing to incoming shortwave irradiance, where 'shortwave irradiance' means that both the incoming and outgoing radiation are integrated across the solar spectrum. "Canopy" means the vegetative covering over a surface. The canopy is often considered to be the outer surfaces of the vegetation. Plant height and the distribution, orientation and shape of plant leaves within a canopy influence the atmospheric environment and many plant processes within the canopy. Reference: AMS Glossary http://glossary.ametsoc.org/wiki/Canopy. The surface_albedo restricted to the area type "vegetation" is related to canopy_albedo, but the former also includes the effect of radiation being reflected from the ground underneath the canopy."
"Downwelling radiation is radiation from above. It does not mean "net downward". The sign convention is that "upwelling" is positive upwards and "downwelling" is positive downwards. The term "shortwave" means shortwave radiation. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics."
"xylene is a generic term for a group of three isomers of dimethylbenzene: m-xylene, p-xylene, and o-xylene M-xylene is a xylene carrying methyl groups at positions 1 and 3. P-xylene is a xylene with methyl groups at positions 1 and 4."
"Largely built-up urban area. ‘Largely built-up’ means contiguous settlement of detached buildings of any size with a building density less than for ‘continuously built-up’ area. The built-up area is mixed with non-urbanised areas (e.g. agricultural, lakes, woods). It must also be noted that ‘suburban’ as defined here has a different meaning than in every day English i.e. ‘an outlying part of a city or town’ suggesting that a suburban area is always associated to an urban area. In our context, a suburban area can be suburban on its own without any urban part."
"All areas, that do not fulfil the criteria for urban or suburban areas, are defined as "rural" areas. There are three subdivisions in this category to indicate the distance to the nearest built-up urban area: Rural – near city: area within 10 km from the border of an urban or suburban area; Rural – regional: 10-50 km from major sources/source areas; Rural – remote: > 50 km from major sources/source areas."
"Located in close proximity to a single industrial source or industrial area. A wide range of industrial sources can be considered here, including thermal power generation district heating plants refineries waste incineration/treatment plants, dump sites mining, including gravel, oil, natural gas airports ports."
"Any location with is neither to be classified as “traffic” or “industrial”. Located such that its pollution levels are representative of the average exposure of the general population (or vegetation and natural ecosystems) within the type of area under assessment. The pollution level should not be dominated by a single source type (e.g. traffic), unless that source type is typical within the area under assessment. The station should usually be representative of a wider area of at least several square kilometres."
"Key party responsible for gathering information and conducting research. This is the person who is responsible for making the measurements and securing the quality of the data. In general, there should be exactly one PrincipalInvestigator associated with every measurement and (a possibly different person) associated with a station. The PrincipalInvestigator may delegate responsibilities, for example to technicians or postdoctoral researchers, and yet remain PrincipalInvestigator as the person overseeing the measurements and data distribution."