Introduction
Atmospheric composition can be observed using various instruments (satellite and ground-based) and can be analysed and forecasted using numerical models. This training module provides an overview of available online resources that can be used to assess an air pollution or a Sahara dust event. An air pollution event is defined as a time during which the concentration of atmospheric pollutants exceeds air quality standards. In southern Europe, these also include Sahara dust events, which occur mostly in spring and summer, when south-westerly flow transports desert dust from the areas south of the Atlas Mountain range.
This module consists of four chapters. In this first chapter, the key air pollutants, and their sources and health effects, are introduced. The key air pollutants are nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), sulphur dioxide (SO2), and atmospheric aerosol particles, also called particulate matter (PM). Saharan dust and Second Inorganic Aerosols (SIA; formed from ammonia (NH3), nitrogen (di)oxide, and sulphur dioxide) are included in PM. The use of nitrogen dioxide as an air pollution indicator is then described, followed by a selection of the World Health Organization (WHO) and European Union (EU) regulations and standards. Finally, the last section of this chapter focuses on the effect of meteorological conditions on chemical processes and, in a few cases, the other way around. Chapter 2 presents selected online resources of satellite observations and other information resources useful for assessing air quality. Two case studies are investigated in chapter 3: a Sahara dust event in the south of Europe in March 2022, and the 2019 Po Valley air pollution event. The training module concludes with an exercise on the 2019 Po Valley air pollution event.
Note: to limit confusion, the word 'sources' is only used for a physically existing source of atmospheric gases and particles, while the word 'resource' is used for online sources of information.
Aim of this training module:
In this air quality module, you will learn to respond (better) to air pollution and Sahara dust events, by learning which resources to use for these events.
Goals of this training module:
- Describe the health effects of key air pollutants such as particulate matter, ozone, and nitrogen dioxide.
- List the major air pollution sources of particulate matter, ozone, and nitrogen dioxide.
- Interpret satellite and non-satellite air quality resources.
- Explain the effects of Sahara dust events on the weather.
- Identify atmospheric conditions leading to air pollution events.