The investigators will conduct a comprehensive study of the chemistry and dynamics in the mesosphere and lower thermosphere (MLT) using existing and new data. The tasks include the development of a new radar capability to measure nighttime Fe+ concentrations, and enhanced lidar capabilities for temperature and wind measurements. The objectives are to characterize relationships among atomic metals and electron concentration, compare chemistries of meteoric species in MLT through simultaneous observations, and investigate the response of metal layers to gravity waves and tides. In the last two decades, there have been a number of simultaneous and common volume observations of meteoric species, including, Ca, Fe, K, Na, and Ca+, as well as electron concentration (Ne) and temperature in the mesopause region at Arecibo. The simultaneous observation of multiple species offers the advantage that the atmospheric conditions are identical. With the anticipated radar measurement of Fe+, the observations will allow for comparative studies on ion-molecular and neural-molecular chemistries. Also, the influence of dynamical versus chemical transport and its variation with the altitude will be investigated. The study will help in the development of atmospheric models and improve knowledge of mesospheric chemistry and dynamics. It will involve graduate and undergraduate students from Miami University, as well as students from universities in Puerto Rico, and will strengthen international collaborations with scientists from at least two other countries. The results are expected to help to improve atmospheric models used by the broader atmospheric community.
