Introduction

• Air Quality / Air Pollution issues will be areas of increasing concern to MSC
• AQ is primarily a provincial responsibility, with the Federal government providing a coordinating role in terms of standards, etc.
• AQ is an issue on many scales:
  • global (e.g. GHG's, stratospheric ozone, transport of HAPs)
  • regional (e.g. LRTAP / acid rain)
  • mesoscale / local (within a 20 km radius of source, controlled by mesoscale meteorology)
• atmospheric constituents affecting AQ have natural and anthropogenic sources
• pollutants are broadly classified as:
  • primary - those emitted directly by a source, (e.g. SO_x, NO_x, CO_x, HC etc.)
  • secondary - those which result from transformations and reactions in the atmosphere after release (e.g. tropospheric ozone)
• both primary and secondary pollutants are either gaseous or particulate pollutants
• inhalable particulates are pollutants of emerging concern, in part because there appears to be no threshold below which there are no health impacts
• PM > 10 $\mu$m in diameter are not inhalable
• PM < 2.5 $\mu$m in diameter (PM_2.5) can be inhaled deeply into the lungs where they may impact health
• This presentation will overview:
  • air pollution meteorology
  • air quality in regions of complex terrain
  • the role of synoptic meteorology in addressing air quality issues
• [OH: Ahrens 17.2, NAAQO's, Boubel 18-1]