Chemical climate

The climatological and seasonal distributions of chemical species (i.e., the chemical climate) calculated by CHASER have already been evaluated in Sudo et al. (2002b, 2003). The focus here is on the validation and interpretation of the chemical... 

Effects of Changes in Chemical Climate on Water, Soils and Biota... 

The following changes in chemical climate have special importance for biota ... 

Interest in precipitation chemistry dates back to the 18th century, but only since 1977 has the U.S. established a national network for monitoring at a level sufficient to describe the chemical climate. The siting criteria, quality assurance, and standardized equipment and analytical methodology are addressed to insure the highest quality data for interpretative research. The national distribution of concentration and deposition for calcium, ammonium, chloride, nitrate, sulfate, and pH are shown in a series of maps. 

This total data philosophy covers information accrued from the time a new drug entity is discovered, through preformulation studies to final formulation in terms of physical, chemical, climatic and microbiological challenge so that the product characteristics, deterioration, degradation, etc. are established before it is placed into contact with a pack/device. 

The chemical composition of air depends on the natural and man-made sources of the constituents (their distribution and source strength in time and space) as well the physical (e. g. radiation, temperature, humidity, wind) and chemical conditions (other trace species) which determine transportation and transformation. Thus, atmospheric chemistry is not a pure chemistry and also includes other disciplines which are important for describing the interaction between atmosphere and other surrounding reservoirs (biosphere, hydrosphere, etc.). Measurements of chemical and physical parameters in air will always contain a geographical component, i. e., the particularities of the locality. That is why the terms chemical weather and chemical climate have been introduced. For example, diurnal variation of the concentration of a substance may occur for different reasons. Therefore general conclusions or transfer of results to other sites should be done with care. On the other hand, it is a basic task in atmospheric chemistry not only to present local results of chemical composition and its variation in time, but also to find general relationships between pollutants and their behavior under different conditions. 

Looking into details of the smoothed H2O2 ice core record (Fig. 2.86) it seems obvious to distinguish between several time periods coimected with different chemical climate, namely ... 

It is remarkable that all these later definitions no longer include Humboldfs statement of variations of the states , but set the climate based on mean or averaged values. It seems that Humboldfs definition, with his focus on biosphere-atmosphere interaction (we will see below that nowadays we accept this definition again in the sense of earth system research) was too broad and - with the rapid mathematical development of meteorology as a physical discipline in the second half of the nineteenth century - it was soon related only to atmospheric properties. But it is worth noting that Loewy (1924) includes not only the physical climate factors (which he considered to be the most important) but also chemical climate factors (in terms of constituents in air). 

When we leave out the short-term time scale, that is, we use the latter sentence concerning the definition of climate, we arrive at a formal definition of chemical climate as ... 

The record of chemical components in climate (i. e., the development of a chemical climatology) is of great importance for societies. Long-term forecast of the chemical climate is extremely important due to the close interaction between the physical and chemical system (climate change) and due to the fact that any feedback response to establish abatement strategies needs many years and even decades to take effect. Climate modelers have lately realized that only a better description of chemical processes will lead to greater soundness regarding important physical... 

Cowling, E.B. (1989). Recent changes in chemical climate and related effects on forests in North America and Europe. Ambio 18, 167-171. 

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