tokens: ACKNOWLEDGEMENTS The Atmospheric Chemistry Experiment (ACE), also known as SCISAT, is a Canadian-led mission mainly supported by the Canadian Space Agency. EJRM is funded by a McGill Science Undergraduate Research Award. The authors thank Yi Huang for his insight on the ACE-FTS data and on stratospheric clouds, Mark Swain for the idea of investigating Earth’s sodium layer, and Emily Pass for her helpful comments on this work. We also thank Yan Bétrémieux, Tyler Robinson, and an anonymous referee for their comments, which significantly improved this work. NBC acknowledges funding from NSERC and FRQNT.
ner_tags: O O B-Instrument I-Instrument I-Instrument B-Instrument O O O B-Instrument O O B-Location O O O O O B-Organization I-Organization I-Organization B-Person O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O O O B-Person I-Person O O O O O B-Dataset I-Dataset O O O O B-Person I-Person O O O O O B-CelestialObjectRegion I-CelestialObjectRegion I-CelestialObjectRegion O B-Person I-Person O O O O O O O O O O B-Person I-Person B-Person I-Person O O O O O O O O O O O O B-Person O O O B-Organization O B-Organization