Senior Research Scientist
NorthWest Research Associates, Inc., Boulder, CO
Hobbies:
Sharon riding Berlin in the Rockies, fall 2011
Sharon riding Berlin at the 2011 Dressage Christmas Show, Plane View Farm
Sharon and Gail at the 2011 Dressage Christmas Show, Plane View Farm
Specialized professional competence:
* Theoretical work
* Computer modeling of convection and body forces
* Ray tracing
Representative recent research:
* Calculated the response of the thermosphere and ionosphere to gravity wave (GW) dissipation in the thermosphere. Found that this dissipation process creates localized thermospheric body forces. Recently determined that these body forces excite large-scale secondary GWs and horizontal neutral winds that are variable in space and time
* Extracted the neutral, background winds at z=180-250 km using PFISR data of a propagating GWs. Also estimated the source of this wave to be secondary GWs excited from mountain wave breaking NW of Poker Flat, Alaska
* Estimated the thermospheric spectra from a deep convective plume and white noise, and found that the GW horizontal and vertical wavelengths increase significantly with altitude.
* Calculated the dissipation altitudes, maximum vertical wavelengths, horizontal distances traveled, and time take to travel these distances for a wide range of GWs in a variety of thermospheric temperatures and from launch altitudes in the lower atmosphere and thermosphere
* Developed a 3D ray-trace code which includes the most important forms of dissipation for high-frequency GWs from the lower atmopshere
* Derived an anelastic GW dispersion relation which includes the most important forms of dissipation for high-frequency GWs from the lower atmopshere
* Derived the Boussinesq and compressible GW and mean responses to intermittent body forces and heatings
* Studied the excitation of secondary waves from GW breaking
* Studied the excitation of GWs from deep convective plumes and mesoscale convective complexes
* Studied the excitation of waves from multiple and intermittent horizontal and vertical body forcings
Other professional experience:
* Postdoc at LASP with Dr. D. Fritts at the University of Colorado, Boulder, Oct. 1995 - Jan. 1997;
* President's Postdoctoral Fellow, Center for Particle Astrophysics, University of California, Berkeley, Sept. 1993 - Sept. 1995;
* Guest Scientist in Numerical Cosmology, Theoretical Astrophysics, Fermi National Accelerator Lab, Jan. - Aug. 1993.
Academic Background:
* B.A. in physics and chemistry (1987), University of Rochester;
* M.A. in physics (1990), University of Chicago;
* Ph.D. in physics (1993), University of Chicago.
Awards and Honors:
* CEDAR Prize Lecturer (2008): "The coupling of the lower atmosphere to the thermosphere via gravity wave excitation, propagation and dissipation"
* Associate Editor, Journal of Geophysical Research, Space Physics, Jan 1, 2010-present.
Publications:
P. Bhaneja, G. D. Earle, P. A. Roddy, C. M. Swenson, A. Barjatya, R. L. Bishop, T. W. Bullett, G. Crowley, R. Redmon, K. Groves, R. Cosgrove, and Sharon L. Vadas, “A Comprehensive Rocket and Radar Study of Midlatitude Spread F, JGR, in press.
Sharon L. Vadas and Han-Li Liu, 2010: "Neutral Winds and Densities at the Bottomside of the F layer from Primary and Secondary Gravity Waves from Deep Convection", Springer book, in press Pdf version of this paper
* Nicolls, M. J., R. H. Varney, S. L. Vadas, P.A. Stamus, C. J. Heinselman, R. B. Cosgrove, and M. C. Kelley, 2010, "Case Study of an Inertia-Gravity Wave in the Mesosphere over Alaska with the Poker Flat Incoherent Scatter Radar", JGR, 115, D00N02, doi:10.1029/2010JD014042. Pdf version of this paper
* J. J. Makela, S.L. Vadas, R. Muryanto, T. Duly, and G. Crowley, 2010: "Periodic spacing between consecutive equatorial plasma bubbles", GRL, 37, L14103, doi:10.1029/2010GL043968. Pdf version of this paper
* Sharon L. Vadas and G. Crowley, 2010: "Sources of the traveling ionospheric disturbances observed by the ionospheric TIDDBIT sounder near Wallops Island on October 30, 2007", JGR, 115, A07324, doi:10.1029/2009JA015053. Pdf version of this paper
Takahashi, H., M. A. Abdu, M. J. Taylor, P.‐D. Pautet, E. de Paula, E. A. Kherani, A. F. Medeiros, C. M. Wrasse, I. S. Batista, J. H. A. Sobral, D. Gobbi, D. Arruda, I. Paulino, S. Vadas, D. Fritts, 2010, "Equatorial ionosphere bottom-type spread F observed by OI 630.0 nm airglow imaging", GRL, 37, L03102, doi:10.1029/2009GL041802.
* Sharon L. Vadas and M.J. Keskinen, 2010: Correction to “Three-dimensional nonlinear evolution of equatorial ionospheric bubbles with gravity wave seeding and tidal wind effects'', GRL, 37, L03101, doi:10.1029/2009GL041216. Pdf version of this paper
* Sharon L. Vadas and Han-Li Liu, 2009: ``The Generation of Large-Scale Gravity Waves and Neutral Winds in the Thermosphere From the Dissipation of Convectively-Generated Gravity Waves'', JGR, 114, A10310, doi:10.1029/2009JA014108. pdf version of this paper
* Sharon L. Vadas and Mike Nicolls, 2009: "Temporal Evolution of Neutral, Thermospheric Winds and Plasma Response using PFISR Measurements of Gravity Waves" JASTP, 71, 740-770. Pdf version of this paper
* Taylor, M.J., P.-D. Pautet, A.F. Medeiros, R.A. Buriti, J. Fechine, D.C. Fritts, S.L. Vadas, H. Takahashi, and F.T. Sao Sabbas, 2009: "Characteristics of mesospheric gravity waves near the magnetic equator, Brazil during the SpreadFEx campaign", Ann. Geophys., 27, 461-472.
* Fritts, D. C., Abdu, M. A., Batista, B. R., Batista, I. S., Batista, P. P., Buriti, R., Clemesha, B. R., Comberiate, J., Dautermann, T., de Paula, E., Fechine, B. J., Fejer, B., D.Gobbi, Haase, J., Kamalabadi, F., Laughman, B., Lima, P. P., Liu, H., Medeiros, A., Pautet, D., ao Sabbas, F. S., Sobral, J. H. A., Stamus, P., Takahashi, H., Taylor, M. J., Vadas, S. L., and Wrasse, C., 2007: "The Spread F Experiment (SpreadFEx): Program overview and first results", Earth, Planets and Space, in press.
* Fritts, D.C., M. A. Abdu, B. R. Batista, I. S. Batista, P. P. Batista, R. Buriti, B. R. Clemesha, T. Dautermann, E. de Paula, B. J. Fechine, B. Fejer, D. Gobbi, J. Haase, F. Kamalabadi, E. R. Kherani, B. Laughman, P. P. Lima, H.-L. Liu, A. Medeiros, D. Pautet, D. M. Riggin, F. S. Rodrigues, F.T. Sao Sabbas, J. H. A. Sobral, P. Stamus, H. Takahashi, M. J. Taylor, S. L. Vadas, F. Vargas, C. Wrasse, 2008a: "Overview and Summary of the Spread F Experiment (SpreadFEx)", Annals Geoph., 27, 2141-2155.
* Sharon L. Vadas, Jia Yue, Joe She, Pete Stamus, and Alan Liu, 2009: "A model study of the effects of winds on concentric rings of gravity waves from a convective plume near Fort Collins on 11 May 2004", Jour. Geoph. Res, 114, D06103, doi:10.1029/2008JD010753. Pdf version of this paper
* Yue, J., S.L. Vadas, C.-Y. She, T. Nakamura, S. Reising, D. Krueger, H.-Li Liu, P. Stamus, D. Thorsen, W. Lyons, T. Li, 2009: "A study of OH imager observed concentric gravity waves near Fort Collins on 11 May 2004", Jour. Geoph. Res, 114, D06104, doi:10.1029/2008JD011244. Pdf version of this paper
* Takahashi, H., M. J. Taylor, P.-D. Pautet, A. F. Medeiros, D. Gobbi, C. M. Wrasse, J. Fechine, M. A. Abdu, I. S. Batista, E. Paula, J.H.A. Sobral, D. Arruda, S. L. Vadas, F. S. Sabbas and D. C. Fritts, 2008: "Simultaneous observation of ionospheric plasma bubbles and mesospheric gravity waves during the SpreadFEx Campaign", Annals Geoph., 27, 1477-1487
* Sao Sabbas, F.T., V. T. Rampinelli, J. Santiago, P. Stamus, S.L. Vadas, G. Dolif Neto, 2008: "Characterization of convective gravity wave sources in satellite IR imagery", Annals Geoph., 27, 1279-1293.
* Fritts, D.C., S.L. Vadas, D.M. Riggin, M.A. Abdu, I.S. Batista, H. Takahashi, A. Medeiros, F. Kamalabadi, H.-L. Liu, B. J. Fejer,and M.J. Taylor, 2008: "Gravity wave and tidal influences on equatorial spread F based on observations during the spread F experiment (SpreadFEx)", Annals Geoph., 26, 3235-3252.
* Sharon L. Vadas and Dave C. Fritts, 2009: "Reconstruction of the gravity wave field excited by convective plumes via ray tracing in real space", Annals. Geophys., 27, 147-177. Pdf version of this paper
* Sharon L. Vadas, M.J. Taylor, P.-D. Pautet, P.A. Stamus, D.C. Fritts, H.-L. Liu, F.T. Sao Sabbas, V.T.Rampinelli, P. Batista, and H. Takahashi, 2009: "Convection: the likely source of the medium-scale gravity waves observed in the OH airglow layer near Brasilia, Brazil, during the SpreadFEx campaign", Ann. Geophys, 27, 231-259. Pdf version of this paper
* Dave C. Fritts and Sharon L. Vadas, 2008: "Gravity wave penetration into the thermosphere: Sensitivity to solar cycle variations and mean winds", Annals. Geophys, 26, 3841-3861. pdf version of this paper
* Sharon L. Vadas and Mike Nicolls, 2008: "Using PFISR Measurements and Gravity Wave Dissipative Theory to Determine the Neutral, Background Thermospheric Winds" Geoph. Res. Letters, 35, {L02105, doi:10.1029/2007GL031522} Pdf version of this paper
* Earle, G.D., A. Mwene-Musumba, and S.L. Vadas, 2008: "Satellite-Based measurements of gravity wave-induced Mid-latitude plasma density perturbations" J. Geoph. Res, 113, A03303, doi:10.1029/2007JA012766. Pdf version of this paper
* Sharon L. Vadas, 2007: "Horizontal and vertical propagation, and dissipation of gravity waves in the thermosphere from lower atmospheric and thermospheric sources", J. Geoph. Res., {112}'{A06305, doi:10.1029/2006JA011845}. Pdf version of this paper
* Sharon L. Vadas and David C. Fritts, 2006: "The influence of solar variability on gravity wave structure and dissipation in the thermosphere from tropospheric convection", J. Geoph. Res., {111, A10S12}'{doi:10.1029/2005JA011510}. Pdf version of this paper
* Sharon L. Vadas and David C. Fritts, 2005: "Thermospheric responses to gravity waves: Influences of increasing viscosity and thermal diffusivity", J. Geoph. Res.,{110, D15103}'{doi:10.1029/2004JD005574}. Pdf version of this paper
* Fritts, D. C., S. L. Vadas, K. Wan, and J. A. Werne, 2005: Mean and variable forcing of the middle atmosphere by gravity waves", J. Atmos. Solar-Terres. Phys., 68, 247-265.
* Sharon L. Vadas and David C. Fritts, 2004: "Thermospheric responses to gravity waves arising from mesoscale convective complexes", J. Atmos. Terr. Sci., 66, 781-804. Pdf version of this paper
* Sharon L. Vadas, David C. Fritts, and M. Joan Alexander, 2003: "Mechanism for the generation of secondary waves in wave breaking regions", Jour. Atmos. Sci., 60, 194--214. Pdf version of this paper
* Sharon L. Vadas and David C. Fritts, 2002: "The Importance of spatial variability in the generation of secondary gravity waves from local body forces," Geophys. Res. Lett., 29(20) 10.1029/2002GL015574 Pdf version of this paper
* David C. Fritts, Sharon L. Vadas, and Y. Yamada, 2002: "An estimate of strong local body forcing and gravity wave radiation based on OH airglow and meteor radar observations", Geophy. Res. Lett, 29(10) 10.1029/2001GL013753 Pdf version of this paper
* Ben Balsley, David C. Fritts, R. Frehlich, M. Jones, S.L. Vadas, R. Coulter, 2002: "Up-gully flow in the great plains region: a mechanism for perturbing the nightime lower atmosphere", Geophys. Res. Lett., 29(19) 10.1029/2002GL015435 Pdf version of this paper
* Sharon L. Vadas and David C. Fritts, 2001: "Gravity wave radiation and mean responses to local body forces in the atmosphere,"Jour. Atmos. Sci., 58, 2249--2279. Pdf version of this paper
* David C. Fritts, Sharon L. Vadas and Oyvind Andreassen, 1998: "Gravity wave excitation and momentum transport in the solar interior: Implications for a residual circulation and lithium depletion," Astronomy & Astrophysics, 333, 343-361
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