In 1992 Hagan was made a Senior Scientist at the National Center for Atmospheric Research (NCAR) High Altitude Observatory.[1][4] She held various roles at NCAR, including acting as Director of the Advanced Study Program, Deputy Director and Interim Director.[1] She developed the Global Scale Wave Model (GSWM), which describes the Rossby waves and solar tides within the Earth's atmosphere.[5] Her model incorporated a gravity wave stress parametrisation and adaptions to the atmospheric background using Upper Atmosphere Research Satellite (UARS) climatologies.[6] She studies several layers of the atmosphere, including the mesosphere, Ionosphere and thermosphere.[1] She is interested in how these atmospheric layers couple together, as well as how they influence tides and Rossby waves.[1] She also studies the downward effect of space weather.[7]
In 2006 she was part of the team who identified the first global connection between space weather and weather on Earth. The collaboration used the IMAGE spacecraft to study plasma bands in the upper atmosphere, finding ultra bright areas that were located above thunderstorms in tropical rainforests.[8]Atmospheric tides are global-scale waves that are excited by the heating of the lower and middle atmosphere due to the absorption of solar radiation and the latent heating of evaporation when raindrops form in tropical clouds.[9] Hagan used her GSWM to simulate the atmospheric tides produced by thunderstorms in tropical rainforests, finding that some of these tides would deposit their energy in the Kennelly–Heaviside layer. This results in a disruption of the Kennelly–Heaviside layer plasma currents and creates bright, dense zones.[8] Hagan was also a member of the Upper Atmosphere Research Satellite team, studying the dynamic chemical signatures of the middle atmosphere.[10]
Hagan joined the Utah State University in September 2015.[11]
^Hagan, M. E.; Oliver, W. L. (1985). "Solar cycle variability of exospheric temperature at Millstone Hill between 1970 and 1980". Journal of Geophysical Research: Space Physics. 90 (A12): 12265–12270. Bibcode:1985JGR....9012265H. doi:10.1029/JA090iA12p12265. ISSN2156-2202.
^Medicine, National Academies of Sciences, Engineering, and; Education, Division of Behavioral and Social Sciences and; Society, Board on Environmental Change and; Studies, Division on Earth and Life; Climate, Board on Atmospheric Sciences and; Program, Committee to Advise the U. S. Global Change Research (2016-03-02). Enhancing Participation in the U.S. Global Change Research Program. National Academies Press. ISBN9780309380263.{{cite book}}: CS1 maint: multiple names: authors list (link)