Aura/MLS observes and SD-WACCM-X simulates the seasonality, quasi-biennial oscillation and El Niño–Southern Oscillation of the migrating diurnal tide driving upper mesospheric CO primarily through vertical advection
<p>This work uses 17 years of upper mesospheric carbon monoxide (CO) and temperature observations by the microwave limb sounder (MLS) on-board the Aura satellite to present and explain the seasonal and interannual variability of the migrating diurnal tide (DW1) component of upper mesospheric C...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/1705/2023/acp-23-1705-2023.pdf |
| Summary: | <p>This work uses 17 years of upper mesospheric carbon
monoxide (CO) and temperature observations by the microwave limb sounder
(MLS) on-board the Aura satellite to present and explain the seasonal and
interannual variability of the migrating diurnal tide (DW1) component of
upper mesospheric CO. This work then compares these observations to
simulations by the specified dynamics – whole atmosphere community climate
model with ionosphere/thermosphere extension (SD-WACCM-X). Results show
that, for all seasons, MLS CO local-time perturbations peaks above
85 km and
has a latitude structure resembling the (1,1) mode in temperature. On the
other hand, SD-WACCM-X DW1 also peaks above 85 km and has a latitude
structure resembling the (1,1) mode, but it simulates two local maximum of the
(1,1) mode between 85 and 92 km. Despite the differences in altitude
structure, a tendency analysis and the adiabatic displacement method
revealed that, on seasonal and interannual timescales, observed and modeled
CO's (1,1) component can be reproduced solely using vertical advection. It
was also found that both observed and modeled CO's (1,1) component contains
interannual oscillations with periodicities close to that of the
quasi-biennial oscillation and the El Niño–Southern Oscillation. From these
results, this work concludes that on seasonal and interannual timescales,
the observed and modeled (1,1) mode affects the global structure of upper
mesospheric CO primarily through vertical advection.</p> |
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| ISSN: | 1680-7316 1680-7324 |