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Dive into quantitative spectroscopy applied to Earth’s atmosphere, emphasizing fundamental analysis principles, instrument platforms, geometries, modes, and wavelengths. Connect with extensive resources and research in atmospheric gas measurements. Discover collaborations, challenges, and cutting-edge research in atmospheric science.
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The Physics of Atmospheric Gas Measurements1. Introduction to quantitative spectroscopy applied to the Earth’s atmosphere Kelly Chance Harvard-Smithsonian Center for Astrophysics
Acknowledgements I thank my many colleagues at the Harvard-Smithsonian Center for Astrophysics, the Harvard Atmospheric Chemistry Modeling Group, and elsewhere. Satellite instrumentation, support, and collaboration has been generously supplied by NASA, the European Space Agency, and German, Dutch, Belgian, and Finnish agencies. My research on these topics has been generously supported primarily by NASA and the Smithsonian Institution. These lectures are available at: https://www.cfa.harvard.edu/~kchance/IAP-CAS-2010/IAP-CAS.html Note time and date: they are subject to change
Introduction to quantitative spectroscopy applied to the Earth’s atmosphere • Emphasize principle of doing analyses from • bedrock and testing all assumptions • For modelers: knowing where measurements • come from and what their limitations are • Hoping for intimacy, interaction, interruptions, • collaborations and students • I will discuss various • platforms (ground-based, airplane, balloon, satellite); • geometries (zenith, limb, nadir); • modes (emission, absorption, scattering); • wavelengths (microwave, infrared, visible, ultraviolet). Our job: To be the skunk at the garden party!
Occam’s Razor Frustra fit per plura, quod fieri potest per pauciora. Essentia non sunt multiplicada praeter necessitatem. - William of Occam
http://www.aapscience7.net/Chapter%20Work/radec_earth_orbit.gif, from Bowie Jr. High School, Odessa, TX.
http://earthguide.ucsd.edu/images/bas/sun/helions.gif, Geosciences Research Division, Scripps Institution of Oceanography. Also, see http://www.cfa.harvard.edu/~kchance/eps238/refdata10/solar/solar.dat
Note the use of the ideal gas law to determine ρ. How much would the use of the van der Waals correction for non-ideal behavior change the P,T relationship in the Earth’s atmosphere?
High resolution solar reference spectrum SAO 2010 irradiance at http://www.cfa.harvard.edu/atmosphere/; paper at /publications
Solar Irradiance Liou, 2002
When does emission start and end? - MIPAS HCl - CO fundamental and overtone Emission also at night – remember for later
When e-τ≈ 1 – τ, the absorption is optically thin. Important for later.
Broadening vs. Temperature Where –n is the power of the variation of the scattering Potential with radial distance, r r-3→ T-1 “self-polar” r-4→ T-5/6 “polar-air” r-∞→ T-1/2 “hard sphere” Townes and Schawlow, Microwave Spectroscopy