Atmospheric Measurement Techniques
A new technique for the satellite remote sensing of greenhouse gases in the atmosphere via the absorption of short-wave infrared laser signals transmitted between counter-rotating satellites in low Earth orbit has recently been proposed; this would enable the acquisition of a long-term, stable, global set of altitude-resolved concentration measurements. We present the first ground-based experimental demonstration of this new infrared-laser occultation method, in which the atmospheric absorption of CO2 near 2.1µm was measured over a ∼144km path length between two peaks in the Canary Islands (at an altitude of ∼2.4 km), using relatively low power diode lasers (∼4 to 10mW). The retrieved CO2 volume mixing ratio of 400 ppm (±15 ppm) is consistent within experimental uncertainty with simultaneously recorded in situ validation measurements. We conclude that the new method has a sound basis for monitoring CO2 in the free atmosphere; other greenhouse gases such as methane, nitrous oxide and water vapour can be monitored in the same way.
Original Publication Citation
Brooke, J.S.A., Bernath, P.F., Kirchengast, G., Thomas, C.B., Wang, J.G., Tereszchuk, K.A., . . . Loescher, A. (2012). Greenhouse gas measurements over a 144 km open path in the Canary Islands. Atmospheric Measurement Techniques, 5(9), 2309-2319. doi: 10.5194/amt-5-2309-2012
Brooke, J.S. A.; Bernath, P. F.; Kirchengast, G.; Thomas, C. B.; Wang, J. G.; Tereszchuk, K. A.; González Abad, G.; Hargreaves, R. J.; Beale, C. A.; and Harrison, J. J., "Greenhouse Gas Measurements Over a 144 km Open Path in the Canary Islands" (2012). Chemistry & Biochemistry Faculty Publications. 43.