The first global atmospheric model (WACCM-Al) of meteor-ablated aluminum was constructed from three components: the Whole Atmospheric Community Climate Model (WACCM6); a meteoric input function for Al derived by coupling an astronomical model of dust sources in the solar system with a chemical meteoric ablation model; and a comprehensive set of neutral, ion-molecule and photochemical reactions relevant to the chemistry of Al in the upper atmosphere. The reaction kinetics of two important reactions that control the rate at which Al+ ions are neutralized were first studied using a fast flow tube with pulsed laser ablation of an Al target, yielding k(AlO+ + CO) = (3.7 ± 1.1) × 10-10 and k(AlO+ + O) = (1.7 ± 0.7) × 10-10 cm3 molecule-1 s-1 at 294 K. The first attempt to observe AlO by lidar was made by probing the bandhead of the B2Σ+(v’ = 0) ← X2Σ+(v” = 0) transition at λair = 484.23 nm. An upper limit for AlO of 57 cm-3 was determined, which is consistent with a night-time concentration of ~5 cm-3 estimated from the decay of AlO following rocket-borne grenade releases. WACCM-Al predicts the following: AlO, AlOH and Al+ are the three major species above 80 km; the AlO layer at mid-latitudes peaks at 89 km with a half-width of ~5 km, and a peak density which increases from a night-time minimum of ~10 cm-3 to a daytime maximum of ~60 cm‑3; and that the best opportunity for observing AlO is at high latitudes during equinoctial twilight.

The first global atmospheric model of Ni (WACCM-Ni) has been developed to understand recent observations of the mesospheric Ni layer by ground-based resonance lidars. The three components of the model comprise: the Whole Atmospheric Community Climate Model (WACCM6); a meteoric input function derived by coupling an astronomical model of dust sources in the solar system with a chemical meteoric ablation model; and a comprehensive set of neutral, ion-molecule and photochemical reactions pertinent to the chemistry of Ni in the upper atmosphere. In order to achieve closure on the chemistry, the reaction kinetics of three important reactions were first studied using a fast flow tube with pulsed laser ablation of a Ni target, yielding k(NiO + O) = (4.6 +/- 1.4)e-11; k(NiO + CO) = (3.0 +/- 0.5)e-11; and k(NiO2 + O) = (2.5 +/- 1.2)e-11 cm3 molecule-1 s-1 at 294 K. The photodissociation rate of NiOH was computed to be J(NiOH) = 0.02 s-1. WACCM-Ni simulates satisfactorily the observed neutral Ni layer peak height and width, and Ni measurements from rocket-borne mass spectrometry. The Ni layer is predicted to have a similar seasonal and latitudinal variation as the Fe layer, and its usually broad bottom-side compared with Fe is caused by the relatively fast NiO + CO reaction. The quantum yield for photon emission from the Ni + O, observed in the nightglow, is estimated to be between 6 and 40%.