This book contributes to more reliable and realistic predictions by
focusing on sampling times from a few seconds to a few hours. Its
objectives include developing clear definitions of statistical terms,
such as plume sampling time, concentration averaging time, receptor
exposure time, and other terms often confused with each other or
incorrectly specified in hazard assessments; identifying and quantifying
situations for which there is no adequate knowledge to predict
concentration fluctuations in the near-field, close to sources, and far
downwind where dispersion is dominated by atmospheric turbulence;
identifying areas where further information is required to define
concentration variability statistics; and formulating an operation model
for concentration fluctuations based on the current state of knowledge
of dispersion processes.