Earths Atmosphere Evolution Additional references Evolution of the

Earth’s Atmosphere Evolution – Additional references – – – Evolution of the atmosphere (Walker, 1975) Chemistry of Atmospheres (Wayne, 1991) Chemistry of the Natural Atmosphere (Warneck, 2000) Kump, Nature, 2008 Falkowski, Science, 2005 Arrhenius law • Atmospheric fraction of CO 2 • Temperature structure – Manabe and Wetherald, JAS, 1967 – Manabe and Stickler, JAS, 1964 • Atmospheric radiation

Wayne, 1991 Warneck, 2000

Banded iron formations Red beds

Mass dependent fractionation Mass independent fractionation Kump, 2008

Warneck, 2000

Methanogens

http: //www. snowballearth. org/overview. html

Falkowski et al. , 2005

Falkowski et al. , 2005

KH Temperature (K)

JAS, 1964

Fraunhoffer Lines Fe Na O 2 H – Balmer series • First observed by Wollatson (1802). Fraunhoffer independently discovered them in 1814 and studied them thoroughly. • The continuous emission of photosphere is interrupted by selective absorption and re-emission in upper photosphere. Seen in visible and IR spectra only as absorption lines. Lines at < 185 nm appear in emission. • Fraunhoffer mapped over 570 lines. Later these lines were associated with atoms/molecules in the upper solar atmosphere.

Primary atmospheric molecules involved in absorption of radiation • Atmospheric molecules are characterized by discrete rotational and vibrational energy states in addition to the electronic transitions. • Transitions – Electronic – Ionization, dissassociation – UV some visible. – Vibrational – IR, far IR – Rotational – far IR, microwave • The lower energy states significantly impact terrestrial radiation, which peaks in the IR. Bohren and Clothiaux, 2006

Ionize Dissasociate Vibrational --- Rotational

CO 2 O 3 CH 4 H 2 O