HAO 2010 PROFILES IN SCIENCE: Dr. Barbara Emery
Contact
303-497-1596
emery@ucar.edu
Dr. Barbara Emery received a Science Doctorate (PhD) from the Department of Meteorology at the Massachusetts Institute of Technology in May 1977 using Millstone Hill incoherent scatter radar data in her thesis. She took a Centre National de Recherche en Science (CNRS) post-doc in France to work with St. Santin incoherent scatter radar data before joining the National Center for Atmospheric Research in September 1978 to work as a project scientist I with Raymond Roble on Dynamics Explorer Satellite data and the NCAR Thermospheric General Circulation Model (TGCM). She had met Ray Roble at her first job at NCAR as a summer graduate student in the Computer Science section of NCAR when Ray was her summer advisor.
She later worked with Arthur Richmond and the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure. She has been an Associate Scientist IV in the High Altitude Observatory since 1987. She has been involved with the Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) Database since 1987, formerly known as the Incoherent Scatter Radar Database. She has been making the local arrangements for the annual CEDAR Workshop since 1988. She is responsible for many of the CEDAR web pages and has been a long-time ex-officio member for the CEDAR Science Steering Committee (CSSC).
Her interests center on dynamics and energetics, with particular interest in the high latitude inputs. One of her accomplishments with the CEDAR Database was to intercalibrate and clean up estimates of the electron or total hemispheric power from 24 satellites from the National Oceanic and Atmospheric Administration (NOAA) and Defense Meteorological Satellite Program (DMSP) that went back to 1978. She also intercalibrated the ion hemispheric power from 5 NOAA Space Environmnet Monitor 2 (SEM-2) instruments on board 4 NOAA and 1 European Meteorological Operational (MetOp-02) satellite going back to 1998.
Publications:
Solar rotational periodicities and the semiannual variation in the solar wind, radiation belt, and aurora
Barbara A. Emery (NCAR), Ian G. Richardson (GSFC and CRESST/Department of Astronomy, University of Maryland, College Park, MD 20742), David S. Evans (NOAA), Frederick J. Rich (LL/MIT), and Gordon Wilson (AFRL). Solar Physics, doi:10.1007/s11207-011-9758-x, 2011.
Abstract:
High-speed streams (HSS) dominate the solar rotational periodic amplitudes found in the solar wind and in Earth-based indices such as the radiation belt number flux, the auroral inputs, and the geomagnetic Ap index. The Lomb-Scargle amplitudes over 81 days for periods of 27 days, 13.5 days, 9 days, 6.8 days and 5.4 days were calculated over four solar cycles from 1972 to 2010 using daily averages of these indices, which are plotted in the figure. Minimum values plotted as red circles occur at the end of the shaded solar minimum periods in all but the solar wind density, which is usually anti-correlated with the solar wind velocity. The minimum values in the long and most recent solar minimum are lower than the previous three solar minimum. The shorter period 5-d, 7-d and 9-d amplitudes were better correlated with each other than the 13.5-d and especially the 27-d amplitudes, and tended to maximize in the descending and early solar minimum phases with HSS, which are plotted in green in the second panel. Interplanetary Coronal Mass Ejections (ICMEs) occur mostly during solar maximum and are plotted in red, with slow-speed winds plotted in blue. The majority of the temporal variations in all indices are approximated by the sum of the 13.5-d and 27-d amplitudes added to a baseline, which are plotted as dark-green lines compared to the observations in black. Semi-annual amplitudes are stronger in Earth-based parameters due to geometrical factors that enhance the natural equinoctial peaks in the solar wind parameters due to the movement of the Earth above and below the heliospheric current sheet. The semi-annual amplitudes over 569-day blocks for both solar wind and Earth-based parameters were found to be primarily the result of equinoctial peaks in the 13.5-d and 27-d amplitudes.
Relevant Publications:
Ahn, B.-H., B. A. Emery, H. W. Kroehl, and Y. Kamide, Climatological characteristics of the auroral ionosphere in terms of electric field and ionospheric conductance, J. Geophys. Res., 104, 10,031-10,040, 1999.
Chun, F. K., D. J. Knipp, M. G. McHarg, G. Lu, B. A. Emery, S. Vennerstrom and O. A. Troshichev, Polar cap index as a proxy for hemispheric Joule heating, Geophys. Res. Lett., 26, 1101-1104, 1999.
Chun, F. K., D. J. Knipp, M. G. McHarg, J. R. Lacey, G. Lu, and B. A. Emery, Joule heating patterns as a function of polar cap index, J. Geophys. Res., 107(7), 10.1029/2001JA000246, 2002.
Emery, B. A., V. Coumans, D. S. Evans, G. A. Germany, M. S. Greer, E. Holeman, K. Kadinsky-Cade, F. J. Rich and W. Xu, Seasonal, Kp, solar wind, and solar flux variations in long-term single pass satellite estimates of electron and ion auroral hemispheric power, in review, J. Geophys. Res., Jan 2008.
Emery, B. A., D. S. Evans, M. S. Greer, E. Holeman, K. Kadinsky-Cade, F. J. Rich and W. Xu, The low energy auroral electron and ion hemispheric power after NOAA and DMSP intersatellite adjustments, NCAR Scientific and Technical Report, STR#470, 2006. Final (12/22/06) on-line at http://cedarweb.hao.ucar.edu/instruments/str470.pdf
Emery, B. A., C. Lathuillere, P. G. Richards, R. G. Roble, M. J. Buonsanto, D. J. Knipp, P. Wilkinson, D. P. Sipler and R. Niciejewski. 1999: Time dependent thermospheric neutral response to the 2-11 November 1993 storm period, J. Atmos. Solar Terr. Phys., 61, 329-350.
Emery, B. A., I. G. Richardson, D. S. Evans, and F. J. Rich. 2009: Solar wind structure sources and periodicities of global electron hemispheric power over three solar cycles. J. Atmos. Solar Terr. Phys., 71., doi:10.1016/j.jastp.2008.08.005.
Fang, X., M. W. Liemohn, J. U. Kozyra, D. S. Evans, A. D. DeJong and B. A. Emery, Global 30-240 keV proton precipitation in the 17-18 April 2002 geomagnetic storms: 1. Patterns, J. Geophys. Res., 112, A05301, doi: 10.1029/2006JA011867.
Gibson, S E, J U Kozyra, G de Toma, B A Emery, T Onsager, and B J Thompson. 2009: If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals, J. Geophys. Res., 114, A9, doi:10.1029/2s2009JA014342.
Guo, J., X. Feng, B. A. Emery, J. Zhang, C. Xiang, F. Shen, and W. Song. 2011: Energy transfer during intense geomagnetic storms driven by interplanetary coronal mass ejections and their sheath regions. J. Geophys. Res., 116, A05106, doi:10.129/2011JA016490.
Knipp, D. J., B. A. Emery, A. D. Richmond, N. U. Crooker, M. R. Hairston, J. A. Cumnock, W. F. Denig, F. J. Rich, O. de la Beaujardiere, J. M. Ruohoniemi, A. S. Rodger, G. Crowley, B.-H. Ahn, D. S. Evans, T. J. Fuller-Rowell, E. Friis-Christensen, M. Lockwood, H. W. Kroehl, C. G. Maclennan, A. McEwin, R. J. Pellinen, R. J. Morris, G. B. Burns, V. Papitashvili, A. Zaitzev, O. Troshichev, N. Sato, P. Sutcliffe, and L. Tomlinson. 1993: Ionospheric convection response to slow, strong variations in a northward Interplanetary Magnetic Field: A case study for January 14, 1988, J. Geophys. Res., 98, 19273-19292.
Knipp, D. J., B. A. Emery, M. Engebretson, X. Li, A. H. McAllister, T. Mukai, S. Kokubun, G. D. Reeves, D. Evans, T. Obara, X. Pi, T. Rosenberg, A. Weatherwax, M. G. McHarg, F. Chun, K. Mosely, M. Codrescu, L. Lanzerotti, F. J. Rich, J. Sharber and P. Wilkinson. 1998: An overview of the early November 1993 geomagnetic storm. J. Geophys. Res., 103, 26,197-26, 220.
Knipp, D. J., W. K. Tobiska and B. Emery, Extreme upper atmospheric heating events of Solar Cycles 21-23, submitted to Solar Physics, Sep 2004.
Kozyra, J.U., G. Crowley, B. A. Emery, X. H. Fang, G. Maris, M. G. Mlynczak, R. J. Niciejewski, S. E. Palo, L. J. Paxton, C. E. Randall, P.-P. Rong, J. M. Russell III, W. Skinner, S. C. Solomon, E. R. Talaat, Q. Wu, and J.-H. Yee, Response of the upper/middle atmosphere to coronal holes and powerful high-speed solar wind streams in 2003, in Recurrent Magnetic Storms: Corotating Solar Wind Streams, edited by B. T. Tsurutani, R. L. McPherron, W. D. Gonzalez, G. Lu, J. H. A. Sobral, and N. Gopalswamy, Geophysical Monograph Series 167, American Geophysical Union, 10.1029/167GM24, pp 319-340, 2006.
Kwak, Y.-S., B.-H. Ahn, B. A. Emery, J. P. Thayer, M. McCready and J. F. Watermann, Electrodynamical characteristics of the polar ionosphere over the auroral and polar cap regions based on incoherent scatter radar measurements, J. Atmos. Solar-Terr. Phys., 68, 881-900, 2006.
Lu, G., A. D. Richmond, B. A. Emery, and R. G. Roble, Magnetosphere-ionosphere-thermosphere coupling: Effect of neutral winds on energy transfer and field-aligned current, J. Geophys. Res., 100, 19,643-19,659, 1995.
McHarg, M., F. Chun, D. Knipp, G. Lu, B. Emery, and A. Ridley, High-latitude Joule heating response to IMF inputs, J. Geophys. Res., 110, A08309, doi: 10.1029/2004JA010949.
Roble, R. G. and B. A. Emery, On the global mean temperature of the thermosphere, Planet. Space Sci., 31, 597-614, 1983.
Slinker, S. P., J. A. Fedder, B. A. Emery, K. B. Baker, D. Lummerzheim, J. G. Lyon and F. J. Rich, Comparison of global MHD simulations with AMIE simulations for the events of May 19-20, 1996, J. Geophys. Res., 104, 28379-28395, 1999.
Turner, N. E., E. J. Mitchell, D. J. Knipp and B. A. Emery, Energetics of magnetic storms driven by corotating interaction regions: A study of geoeffectiveness, in Recurrent Magnetic Storms: Corotating Solar Wind Streams, edited by B. T. Tsurutani, R. L. McPherron, W. D. Gonzalez, G. Lu, J. H. A. Sobral, and N. Gopalswamy, Geophysical Monograph Series 167, American Geophysical Union, 10.1029/167GM, pp 113-124, 2006.