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Maura Hagan was awarded a B.A. in physics from Emmanuel College in 1975, and both M.S. and Ph.D. degrees in physics from Boston College in 1980 and 1986, respectively. Between 1986 and 1992, she was a staff member at Massachusetts Institute of Technology Haystack Observatory. She joined the staff of the National Center for Atmospheric Research High Altitude Observatory (NCAR/HAO) in 1992 and was promoted to Senior Scientist in 2003. She became the Director of the NCAR Advanced Study Program in 2005 and the NCAR Deputy Director in 2008.
Her research interests are centered on investigations of the mesosphere, thermosphere and ionosphere with emphases on the coupling between these atmospheric regions and the generation and propagation of tides and planetary waves therein as well as in regions below. She has authored or co-authored more than 85 refereed publications. For several years she served as the project leader for the Coordinated Analysis of the Thermosphere within the National Science Foundation Coupling Energetics and Dynamics (CEDAR) Program. She was associate editor for Geophysical Research Letters (1993-1997), a member of the National Research Council (NRC) Committee on Solar Terrestrial Research (1996-2000) and the CEDAR Science Steering Committee (1997-2000).
She served on the Steering Committee of the Significant Opportunities in Atmospheric and Related Sciences (SOARS) program (1996-2001), the Atmosphere-Ionosphere-Magnetosphere Panel for the Solar and Space Physics Community Assessment and Strategy for the Future, as a Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) Scientific Discipline Representative to the International Council of Scientific Unions (1999-2007), the NASA Geospace Management Operations Working Group (2003-2007), and co-chaired the SCOSTEP Planetary Scale Mesopause Observing System Steering Committee (1998-2002). She is currently a member of the NRC Committee on Solar and Space Physics.
To read Maura Hagan's curriculum vitae, click here.
Pedatella, N., M.E. Hagan, and A. Maute, 2012: The comparative importance of DE3, SE2, and SPW4 on the generation of wavenumber-4 longitude structures in the low-latitude ionosphere during September equinox. Geophysical Research Letters, 39, L19108, DOI: 10.1029/2012GL053643. [Full text article click here].
Abstract: Numerical simulations are performed to investigate the generation of the wave-4 longitude variation in the low-latitude ionosphere due to the diurnal eastward propagating nonmigrating tide with zonal wavenumber 3 (DE3), semidiurnal eastward propagating nonmigrating tide with zonal wavenumber 2 (SE2), and stationary planetary wave 4 (SPW4). From a fixed local time perspective, the DE3, SE2, and SPW4 all appear as wave-4 structures in longitude, and thus each of these waves must be considered as a potential source of the wave-4 variation in the ionosphere. Both the DE3 and SPW4 are found to produce significant wave-4 variations in the equatorial vertical E × B drift velocity, and in the ionospheric peak density (NmF2) at 15°N magnetic latitude. The daytime wave-4 variation in NmF2 is driven by the combination of vertical E × B drift variability and in-situ effects due largely to meridional neutral winds. The simulation results indicate that the SE2 is not a contributor to the wave-4 longitude variation. Our results further demonstrate that the actual wave-4 longitude variation is due to a combination of the DE3 and SPW4. We therefore conclude that, in addition to the DE3, the SPW4 also needs to be considered as an important driver of the wave-4 longitude variation in the low-latitude ionosphere. We additionally present evidence for the generation of the SPW4 due to the nonlinear interaction between the migrating diurnal tide and the DE3, and demonstrate the impact of DE3 variability on the amplitude of the SPW4.
Pedatella, N., Liu, H., Hagan, M.E., 2012: Day-to-day migrating and nonmigrating tidal variability due to the six-day planetary wave. Journal of Geophysical Research-Space Physics, 117, A06301, 10.1029/2012JA017581. [Full text article click here].
Abstract: To investigate day-to-day variability in the mesosphere and lower thermosphere (MLT), an idealized simulation of a six-day westward propagating zonal wave number-1 planetary wave is performed using the National Center for Atmospheric Research (NCAR) Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIME-GCM). The six-day planetary wave introduces a six-day periodicity in the zonal mean atmosphere, migrating and nonmigrating tides, as well as in secondary waves that are produced by nonlinear planetary wave-tide interactions. We have further used the linear Global Scale Wave Model (GSWM) to isolate the effect of how the day-to-day changes in zonal mean zonal winds may influence tides in the MLT. The most significant changes are observed in the migrating diurnal tide (DW1), eastward propagating nonmigrating tides with zonal wave numbers-2 and -3 (DE2 and DE3), and a 20 hr eastward propagating wave with zonal wave number-2 (20E2). Because we have included the lower atmospheric source of nonmigrating tides, DE2 and DE3 are present with relatively large amplitudes in the MLT, even in the absence of planetary wave forcing. The 20E2 wave is produced by the nonlinear interaction between the DE3 and the six-day planetary wave, and its large amplitude indicates the importance of including the realistic spectra of nonmigrating tides in numerical simulations of planetary waves. The GSWM simulations reveal that the DW1 is not significantly influenced by the changes in the zonal mean winds.
Chang, L.C., Ward, W.E., Palo, S.E., Du, J., Wang, D.-Y. et al., 2012: Comparison of diurnal tide in models and ground-based observations during the 2005 equinox CAWSES tidal campaign. Journal of Atmospheric and Solar-Terrestrial Physics, 78-79, 19–30, 10.1016/j.jastp.2010.12.010. [Full text article click here].
Abstract: In this study, ground-based observations of equinox diurnal tide wind fields from the first CAWSES Global Tidal Campaign are compared with results from five commonly used models, in order to identify systematic differences. WACCM3 and Extended CMAM are both self-consistent general circulation models, which resolve general climatological features, while TIME-GCM can be forced to approximate specific conditions using reanalysis fields. GSWM is a linear mechanistic model; while GEWM is an empirical model derived from ground-based and satellite observations. The models resolve diurnal tides consistent in latitudinal structure with observations, dominated by the upward propagating (1,1) mode. There is disagreement in the magnitudes of the tidal amplitudes and vertical wavelengths, while differences in longitudinal tidal variability indicate differences in the nonmigrating tides in the models. These points suggest inconsistencies in model forcing, dissipation, and background winds that must be examined as part of a coordinated effort from the modeling community.
(For access to Maura Hagan's publications and other NCAR research, please visit the NCAR Library Open Sky web site. OpenSky is the open access institutional repository supporting UCAR, NCAR, and UCP, extending free and open access to our scholarship for the benefit of research and education.)