Year-end Sale % OFF 
Abstract
Abstract. The NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (WACCM-X) v2.1 has been extended to include the neutral and ion–molecule chemistry and dynamics of three metals (Mg, Na, and Fe), which are injected into the upper mesosphere–lower thermosphere by meteoric ablation. Here we focus on the self-consistent electrodynamical transport of metallic ions in both the E and F regions. The model with full ion transport significantly improves the simulation of global distribution and seasonal variations of Mg+, although the peak density is slightly lower (about 35 % lower in peak density) compared with the SCIAMACHY measurements. Near the magnetic equator, the diurnal variation in upward and downward transport of Mg+ is generally consistent with the “ionosphere fountain effect”. The thermospheric distribution of Fe is shown to be closely coupled to the transport of Fe+. The effect of ion mass on ion transport is also examined: the lighter ions (Mg+ and Na+) are transported above 150 km more easily than the heavy Fe+. We also examine the impact of the transport of major molecular ions, NO+ and O2+, on the distribution of metallic ions.
Highlights
The presence of layers of meteor-ablated metal atoms between 80 and 105 km has been known for decades (Plane et al, 2015)
WACCM-X Mg+ density is slightly underestimated relative to SCIAMACHY observations, which is likely related to the meteoric input functions (MIFs) used in the simulation
Since the metallic ions are the main reservoir for neutral metal atoms in the lower thermosphere (Plane et al, 2015), this is in good agreement with the summer peak occurrence of lower thermospheric neutral Na layers observed by mid-latitude lidars (Wang et al, 2012; Dou et al, 2013; Yuan et al, 2014; Xun et al, 2020)
Summary
The presence of layers of meteor-ablated metal atoms between 80 and 105 km has been known for decades (Plane et al, 2015). The main contribution reported here is to incorporate a self-consistent solution of full global transport of Mg+, Fe+, and Na+ in both the E and F regions, within the chemistry– climate WACCM-X 2.1 model (NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension v2.1), in addition to a detailed description of the neutral and ion–molecule chemistry of these metals and the meteoric ablation source required to model the metal atom layers around 90 km. The final section includes a brief summary and a discussion of future directions with the model
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
