TY  - JOUR
A1  - Richter, Heiko
A1  - Buchbender, Christof
A1  - Güsten, Rolf
A1  - Higgins, Ronan
A1  - Klein, Bernd
A1  - Stutzki, Jürgen
A1  - Wiesemeyer, Helmut
A1  - Hübers, Heinz-Wilhelm
T1  - Direct measurements of atomic oxygen in the mesosphere and lower thermosphere using terahertz heterodyne spectroscopy
Y1  - 2021-01-26
VL  - 2
IS  - 1
JF  - Communications Earth & Environment
DO  - 10.1038/s43247-020-00084-5
PB  - Nature Publishing Group UK
N2  - Atomic oxygen is a main component of the mesosphere and lower thermosphere of the Earth, where it governs photochemistry and energy balance and is a tracer for dynamical motions. However, its concentration is extremely difficult to measure with remote sensing techniques since atomic oxygen has few optically active transitions. Current indirect methods involve photochemical models and the results are not always in agreement, particularly when obtained with different instruments. Here we present direct measurements—independent of photochemical models—of the ground state <sup>3</sup>P<sub>1</sub> →<sup>3</sup> P<sub>2</sub> fine-structure transition of atomic oxygen at 4.7448 THz using the German Receiver for Astronomy at Terahertz Frequencies (GREAT) on board the Stratospheric Observatory for Infrared Astronomy (SOFIA). We find that our measure ments of the concentration of atomic oxygen agree well with atmospheric models informed by satellite observations. We suggest that this direct observation method may be more accurate than existing indirect methods that rely on photochemical models.
N2  - Atomic oxygen concentrations in the upper atmosphere can be measured directly with an airborne terahertz heterodyne spectrometer. This approach is probably more accurate than indirect estimates from photochemical models, according to a comparison of the two methods.
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11192
ER  -