Overview

Human activity is changing the composition of the atmosphere. This goes beyond the often obvious problems of local and regional pollution – even in remote locations there are changes in concentrations of minor atmospheric constituents such as carbon dioxide, methane and nitrous oxide. These and other long-lived gases affect the balance of radiation of the earth – they are the so-called greenhouse gases. Other long-lived gases are implicated in the decrease in concentration of ozone in the stratosphere.

The ability to understand the current atmospheric budgets of these trace gases is essential if we are to be able to project their future concentrations in the atmosphere. This book concentrates on one group of techniques that are being used to improve our knowledge – the interpretation of spatial distributions of trace-gas concentrations. An important theme of this book is the use of a statistical approach as being essential to obtaining realistic assessments of the uncertainties in the interpretation of trace-gas observations.

Modelling of the atmospheric transport of carbon dioxide (CO2), methane (CH4) and other greenhouse gases is used to interpret the observed spatial distributions of these gases. The spatial distribution of trace-gas concentrations represents a combination of the effect of spatially varying sources and sinks and the effect of atmospheric transport. Therefore a model of atmospheric transport is needed if the source/sink distributions are to be deduced from observed concentrations.