Lecture 1-2024.ppt environment engineering
- 1. Atmospheric Sciences-EnSE 6254 • INSTRUCTOR: JUMA SELEMANI • NELSON MANDELA AFRICAN INSTITUTION OF SCIENCE AND TECHNOLOGY • 2024/2025
- 2. Atmospheric Sciences-EnSE 6254 • About the course -Programme Core/Elective -Total credit:14 -Total hours: 140(Lectures, Practical Training, Assignments, self Studies) • Course aim: (1) Understand physics and chemistry of the atmosphere and the fundamental nature of atmospheric circulations over a broad range of scales. (2) Understand interaction of the atmosphere with the oceans and land (3) Examine theories explaining the large-scale dynamics of the atmosphere (4) To expose students to the biogeochemistry and photochemical processes governing the composition of the atmosphere with application to air pollution and climate change
- 3. Atmospheric Sciences-EnSE 6254 • Course expected learning outcomes Students are expected to have an in-depth knowledge of (1)Physics and chemistry of the atmosphere and atmospheric circulations over a broad range of scales. (2) Interaction of the atmosphere with the oceans and land surface (3) Theories explaining the large-scale dynamics of the atmosphere (4) Biogeochemistry and photochemical of the atmosphere • Teaching and learning methods (1)Lectures, practical, self study, seminars and assignments (2)Study tour to meteorological agencies, climatic/atmospheric data analysis, air quality measurement • Assessment methods: Formative Assessment (40%) and Summative Assessment (60%)
- 4. Atmospheric Sciences-EnSE 6254 • Recommended readings (1) Mak M. 2011. Atmospheric Dynamics. Cambridge University Press, 536pp (2) Andrews D.G., 2010. An Introduction to Atmospheric Physics 2nd edition. Cambridge University Press, 248pp ISBN 978-0- 521-87220-1. (3) Vallis G.K., 2006. Atmospheric and Oceanic Fluid Dynamics: Fundamentals and Large-scale Circulation. Cambridge University Press, 772pp, ISBN 978-0-521-84969-2.
- 5. Atmosphere • What is atmosphere – is a mixture of gases that surrounds the Earth – made up of 78% nitrogen, 21% oxygen, and 1% other gases
- 6. Atmosphere • Atmospheric Pressure and Temperature – The atmosphere is held around the Earth by gravity. – Gravity pulls gas molecules in the atmosphere toward the Earth’s surface, causing air pressure – As altitude increases, air pressure decreases. (Why?) – Air temperature decreases as altitude increases. (why?)
- 7. Atmospheric Sciences • What is atmospheric sciences -Is the study of the Earth's atmosphere and its various physical and chemical processes e.g. precipitation processes, energy movement -Atmospheric sciences is grounded in observation, theory, and modeling. • Application of the knowledge (1) Understanding processes taking place in the atmosphere (2) Accurate weather forecasts
- 8. Layers of the Atmosphere • Troposphere - Lowest Layer - This is where we live - 8 to 12 miles in height - Weather occurs - Temp decreases with height (why) • Stratosphere - Second lowest layer - Temp increases with height (why) - Ozone (03) layer (why) - Absorbs most of the damaging ultraviolet sunlight (UV-B) (why) • Mesosphere - From ~30 to 53 miles up - Temp decreases (why) - Majority of meteors burn up • Thermosphere - Upper atmosphere 53 to ~430 miles up
- 9. Measurements in atmosphere • In order to measure the conditions of the lower atmosphere • The balloons are filled with hydrogen and measure atmospheric conditions • Balloons attached with Radiosondes are released to measures temperature, relative humidity, pressure, and wind speed/direction Read: how temperature, relative humidity, pressure, and wind speed/direction are measured and varies from place to place
- 10. Earth-Atmosphere Energy Balance • What is the main sources of energy on the earth surface? • The earth-atmosphere energy balance is the balance between incoming energy from the Sun and outgoing energy from the Earth. • Read: Hydrological cycles, how energy is transferred and greenhouse effects
- 11. Assignments • Explain theories governing atmospheric circulation • Explain energy budget highlighting different processes taking place in the atmosphere
- 12. Next lecture • Climate definition and theories • Motions in the atmosphere -Conservation of mass (Equation of continuity) -Conservation of momentum -Conservation of Energy (Thermodynamic Equation)