HAO 2011 Profiles In Science: Dr. Barbara Emery

Contact

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

Superposed epoch analyses of the global auroral electron (Pe) and ion (Pi) inputs

Figure: High resolution

(1) 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 ICMEs and their sheath regions, J. Geophys. Res., 116, A05106, doi:10.1029/2011JA016490.

Abstract: The interaction of the solar wind and the Earth's magnetosphere is complex and the phenomenology of the interaction is very different for interplanetary coronal mass ejections (ICMEs) compared to their sheath regions. In this paper, a total of 71 intense (Dst ≤ −100 nT) geomagnetic storm events in 1996–2006, of which 51 are driven by ICMEs and 20 by sheath regions, are examined to demonstrate similarities and differences in the energy transfer. Using superposed epoch analysis, the evolution of solar wind energy input and dissipation are investigated. The solar wind-magnetosphere coupling functions and geomagnetic indices show a more gradual increase and recovery during the ICME-driven storms than they do during the sheath-driven storms. However, the sheath-driven storms have larger peak values. In general, solar wind energy input (the epsilon parameter) and dissipation show similar trends as the coupling functions. The trends of ion precipitation and the ratio of ion precipitation to the total (ion and electron) are quite different for both classes of events. There are more precipitating ions during the sheath-driven storms. On the other hand, a quantitative assessment of the relative importance of the different energy dissipation branches shows that the means of input energy and auroral precipitation are significantly different for both classes of events, whereas Joule heating, ring current and total output energy display no distinguishable differences. The means of electron precipitation are significantly different for both classes of events. However, ion precipitation exhibits no distinguishable differences. The energy efficiency bears no distinguishable difference between these two classes of events. Ionospheric processes account for the vast majority of the energy, with the ring current only being 12–14% percent; of the total. Moreover, the energy partitioning for both classes of events is similar.

Figure caption: Superposed epoch analyses of the global auroral electron (Pe) and ion (Pi) inputs as well as the ratio of Pi to the total (Pt=Pe+Pi) during the ICME-driven and sheath-driven storms. The heavy solid lines and dashed lines define the mean for the ICME-driven and sheath-driven storms respectively, and the shaded area represents the standard deviation.

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.

Emery, B. A., I. G. Richardson, D. S. Evans, F. J. Rich, G. R. Wilson, 2011. Solar rotational periodicities and the semiannual variation in the solar wind, radiation belt, and aurora. Solar Physics, doi:10.1007/s11207-011-9758-x.

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.

Gibson, S. E., G de Toma, BA Emery, P Riley, L Zhao, Y Elsworth, RJ Leamon, J Lei, S McIntosh, R Mewaldt, T Onsager, BJ Thompson, and D Webb, to be submitted June 2011, WHI in the context of a long and structured solar minimum: an overview from Sun to Earth. Solar Physics, WHI special issue. doi: 10.1007/s11207-011-9869-4.

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.

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, 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.

Lei, J., Thayer, J. P., Lu, G., Burns, A. G., Wang, W., Sutton, E. K., Emery, B. A., 2011. Rapid recovery of thermosphere density during the October 2003 geomagnetic storms. J. Geophys. Res., 116, A03306, doi:10.129/2010JA016164.

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.

Thompson, Barbara J., Sarah E. Gibson, Peter C. Schroeder, David F. Webb, Charles N. Arge, Mario M. Bisi, Giuliana de Toma, Barbara A. Emery, Antoinette B. Galvin, Deborah A. Haber, Bernard. V. Jackson, Elizabeth A. Jensen, Robert J. Leamon, Jiuhou Lei, Periasamy K. Manoharan, M. Leila Mays, Patrick S. McIntosh, Munetoshi Tokumaru, Gordon J. D. Petrie, Simon P. Plunkett, Peter Riley, Steven T. Suess, Brian T. Welsch, Thomas N. Woods, 2011. A Snapshot of the Sun Near Solar Minimum: The Whole Heliosphere Interval. Solar Physics, WHI special issue. doi: 10.1007/s11207-011-9891-6.

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.