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Origin of the atmosphere. Neil Savio Dsouza. The billion-eurold questions. 1. Why does Earth have an atmosphere? 2. What was the early atmosphere like? Why? 3. How did our present atmosphere come about?. 1. Why does Earth have an atmosphere?. Enough gravity [ radius, density ]
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Origin of the atmosphere Neil Savio Dsouza
The billion-eurold questions 1. Why does Earth have an atmosphere? 2. What was the early atmosphere like? Why? 3. How did our present atmosphere come about? Bremen University
1. Why does Earth have an atmosphere? • Enough gravity [ radius, density ] • The right temperature [ thermal velocity, states ] • The right raw-materials [ stability ] • Sources of gasses > Sinks Bremen University
Lecture material, Atmospheric Physics, 2003, PEP Bremen University
1. Why does Earth have an atmosphere? • Enough gravity [ radius, density ] • The right temperature [ thermal velocity, states ] • The right raw-materials [ stability ] • Sources of gasses > Sinks Bremen University
What was the early atmosphere like? • The first atmosphere Components*: H2 & He Sources: Space debris Sinks: Thermal escape, Solar wind Lost to space Bremen University
What was the early atmosphere like? • The second atmosphere Components: H2O, CO2, SO2, CO, S2, N2, H2, NH3,,CH4, O2* Sources: Volcanism, photolysis, meteorites Sinks: chemical reactions(CO2,O2), state changes(H2O) Magnetosphere develops* Bremen University
http://www.multinet.no/~trojen/australia/pages/australia%20-%20limestones%202.htmhttp://www.multinet.no/~trojen/australia/pages/australia%20-%20limestones%202.htm Bremen University
What was the early atmosphere like? • The second atmosphere Components: H2O, CO2, SO2, CO, S2, N2, H2, NH3,,CH4, O2* Sources: Volcanism, photolysis, meteorites Sinks: chemical reactions(CO2,O2), state changes(H2O) Magnetosphere develops* Bremen University
http://scijinks.jpl.nasa.gov/en/educators/gallery/spaceweather/solar_wind_comp_L.jpghttp://scijinks.jpl.nasa.gov/en/educators/gallery/spaceweather/solar_wind_comp_L.jpg Bremen University
How did our present atmosphere come about? Bremen University
How did our present atmosphere come about? Bremen University
http://www.ggl.ulaval.ca/personnel/bourque/s4/stromatolites.htmlhttp://www.ggl.ulaval.ca/personnel/bourque/s4/stromatolites.html Bremen University
How did our present atmosphere come about? Bremen University
How did our present atmosphere come about? • Growth of oxygen Lecture material, Atmospheric Physics, 2003, PEP Bremen University
Summary • Earth retained an atmosphere because it had optimal gravity and temperature to sustain one. • Lithosphere, Hydrosphere and biosphere together have contributed to out present atmosphere • Interactions between them must be considered to fully understand the state of our atmosphere at any time. Bremen University