Knowledge Bank

The Tropospheric Emission Spectrometer on the Earth Observing System Aura satellite measures methane in the Earth's atmosphere. Some of the methane channels are located in the Q branch of the $\nu 4$ band of methane at 1300 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$. Using laboratory spectra obtained with the National Solar Observatory's Fourier transform spectrometer at the McMath-Pierce solar telescope, this Q branch was examined for line mixing and speed dependent line shapes for both self-broadening and air-broadening. The analysis also determined line widths, pressure-induced shifts and line mixing as functions of temperature. Comparisons are made to demonstrate the importance of considering line shape effects in satellite measurements of the Earth's atmosphere.}