[P-EM13] Coupling Processes in the Atmosphere-Ionosphere System

[PEM13-14] Vertical Transport of Mesospheric Water Vapor and Carbon Monoxide by the Migrating Diurnal Tide

*Cornelius Csar Jude Salinas^1,2, Dong Wu³, Jae Lee^3,4, Loren Chang^1,2, Jia Yue^3,5, Quan Gan⁶, Liying Qian⁷, Hanli Liu⁷, James Russell III⁸, Martin Mlynczak⁹ (1.Department of Space Science and Engineering, National Central University, Taiwan, 2.Center for Astronautical Physics and Engineering, National Central University, Taoyuan City, Taiwan, 3.NASA Goddard Space Flight Center, Greenbelt, Maryland, USA, 4.Joint Center for Earth Systems Technology, University of Maryland, Baltimore County, Baltimore, Maryland, USA, 5.Catholic University of America, Washington DC, USA, 6.Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, Colorado, USA, 7.NCAR High Altitude Observatory, Boulder, Colorado, USA, 8.Hampton University, Hampton, Virginia, USA, 9.NASA Langley Research Center, Hampton, Virginia, USA)

Keywords:Water Vapor, Carbon Monoxide, Tides

This work presents the seasonality of the monthly-mean migrating diurnal tide (DW1) components of mesospheric water vapor (H₂O) and carbon monoxide (CO) as observed by the Microwave Limb Sounder (MLS) instrument and as simulated by the Specified Dynamics – Whole Atmosphere Community Climate Model with Ionosphere/Thermosphere eXtension (SD-WACCM-X). During equinox seasons, both H₂O DW1 and CO DW1 exhibit latitudinal structure consistent with a hemispherically symmetric (1,1) mode centered at around 75 km and 85 km, respectively. In June solstice, they exhibit latitudinal structure consistent with a distorted (1,1) mode. We then use observations of these tracers and temperatures from MLS and from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument to calculate the DW1 components of these tracers assuming DW1 solely drives it via vertical transport. Our results show the best agreement with their actual DW1 components over the tropics. A tendency analysis using SD-WACCM-X does confirm that the DW1 component of H₂O and CO over the tropics is primarily driven by vertical transport. At the same time, the tendency analysis reveals that meridional advection and chemistry plays non-negligible roles over the middle latitudes. This work therefore concludes that the seasonality of monthly-mean tropical H₂O and CO’s DW1 components are primarily driven by vertical transport. This work suggests that monthly-mean H₂O and CO may be used as tracers for DW1-induced vertical transport in the tropical mesosphere.