02 Atmosphere Ladislava Řezníčková, MSc, PhD 1. Composition of the atmosphere 2. Vertical structure of the atmosphere 3. Controls of weather and climate 4. Energy transfers 5. Earth’s energy budget 6. Anthropogenic influences on Earth’s energy budget Content • Complex and dynamic system consisting of layers of gases that envelop a planet • Environmental sphere allowing the existence of life on the Earth (essential gasses, water supplies, protection from UV radiation…) • The place where the weather takes place Atmosphere • A mix of gases, solid and liquid particles/aerosols (dust, water vapour, ice crystals, pollen, microbes, air pollutants…) Composition of the atmosphere Hess, 2014 • Various possibilities to divide atmosphere into the individual layers (temperature, gas composition, pressure) • Thermal structure of the atmosphere: thermal layers → Vertical structure of the atmosphere Hess, 2014 Vertical structure of the atmosphere Hess, 2014 • 50% of the total mass occurs in the 5-6 km layer, • 75% in the 0-11 km layer, • 99% in the 0-36 km layer Total atmospheric mass: 5.157x1018 kg Controls of weather and climate 1. Latitude https://www.ces.fau.edu/nasa/module-3/why-does-temperature-vary/angle-of-the-sun.php Controls of weather and climate 2. Land-water distribution Hess, 2014 Controls of weather and climate 3. General circulation of the atmosphere • Trade winds • Westerlies Hess, 2014 Controls of weather and climate 4. General circulation of the oceans • warm water (red arrows) • cool water (blue arrows) Controls of weather and climate 5. Altitude Atmospheric temperature drops with increasing altitude by about 0.5 to 0.6 °C per 100 metres (0.9 to 1.1 °F per 328 feet) – normal (temperature) lapse rate Altitudinal zonation Controls of weather and climate 6. Topographic barriers https://www.britannica.com/science/orographic-precipitation - solar energy – primary energy source for most processes in the atmosphere, hydrosphere, and biosphere - processes leading to the warming and cooling of the atmosphere Energy transfers https://www.worldatlas.com/articles/what-is-the-earth-s-energy-budget.html Energy transfers Radiation (emission, W/m2) • emission of electromagnetic radiation from an object (e.g. Sun) • hotter object = more intense radiation https://www.quora.com Reflection – ability of an object to repel/return electromagnetic waves that strike it – different reflection based on wavelength angle Energy transfers Albedo (%) overall reflectivity of an object or surface Energy transfers • assimilation of electromagnetic waves by an object • different absorptive capabilities of various materials and colours Absorption https://nsidc.org/learn/parts-cryosphere/sea-ice/quick-facts-about-sea-ice Energy transfers https://www.ces.fau.edu/nasa/module-2/earth-energy-balance.php • Scattering – deflecting and redirecting of light waves by molecules and particles in the atmosphere – recently increased scattering and diminished intensity of solar radiation striking the surface as a result of recent climate change • Transmission – complete pass of electromagnetic waves through a medium (Earth materials vs. water) – dependence of medium transmission ability on the wavelength radiation (e.g. glass) Energy transfers Hess, 2014 Earth’s energy budget Hess, 2014 • Annual balance between incoming and outgoing radiation Earth’s energy budget Hess, 2014 Main reasons for the unequal warming: 1. angle of incidence 2. atmospheric obstruction 3. day length December solstice Latitudinal energy transport Earth’s energy budget Hess, 2014 Anthropogenic influences on Earth’s energy budget (IPCC AR6: FAQ 7.1, Figure 1) • Enhanced greenhouse effect – increased concentration of greenhouse gases (GHGs) as the result of human activities and the main cause of recent global warming • Pollution of the atmosphere by aerosols – upper layers: increased radiation scattering – decreased shortwave radiation (wasted energy) – lower layers: increased absorption of longwave radiation (additional energy) – global dimming Anthropogenic influences on Earth’s energy budget https://www.metoffice.gov.uk/weather/climate-change/organisations-and-reports/earths-energy-budget-and-climate-sensitivity • Changes in land-use and land cover Anthropogenic influences on Earth’s energy budget Thank you for your attention