HAO 2012 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

Figure: High resolution

(1) Emery, B.A., R.G. Roble, E.C. Ridley, A.D. Richmond, D.J. Knipp, G. Crowley, D.S. Evans, F.J. Rich, and S. Maeda. 2012: Parameterization of the Ion Convection and the Auroral Oval in the NCAR Thermospheric General Circulation Model, NCAR Technical Report, NCAR/TN-491+STR, 43pp, OpenSky Link.

Abstract: The ion convection and auroral precipitation are important inputs to the global thermospheric energy and momentum balance. In various NCAR Thermosphere General Circulation Models (TGCMs), they are described by analytical models whose characteristics are specified by three parameters: total polar cap potential drop ψ, IMF By component, and hemispheric power input HP. The characteristics of the ion convection model are determined from electric potential patterns derived from Assimilative Mapping of Ionospheric Electrodynamics (AMIE) for 3 days using incoherent scatter radars, satellites and magnetometers. These characteristics are sorted in By and compared with various models that have been described in the literature. NOAA and DMSP satellite electron precipitation data over 20 days have been averaged to specify the characteristics of the auroral precipitation. The relationship of hemispheric power to other parameters is explored. Finally, a specific period is examined and the parameterization is adjusted to fit the observations. The parameterizations were developed in 1989 with minimal changes since then.

Figure caption: Plots of the auroral radius Ra determined from perpendicular bisectors from NH and SH DMSP and NOAA orbits plotted as a function of (a,d) hemispheric power level, (b,e) polar cap potential drop from IMF data using the VBQ1 formula and (c,f) polar cap potentials determined from the NH AMIE patterns and averaged over the time intervals of the appropriate NOAA and DMSP satellites, with (d) all points or bins in HP level or in (e,f) 10kV bins in CP. The NOAA and DMSP estimates in the top plots come from 5 periods: *Nov81, xJan84, +Jun84, oSep84, and −Jan85. The fits were the same for the binned and unbinned Ra estimates.

High Resolution

(2) Guo, J., X. Feng, B.A. Emery, Y. Wang. 2012: Efficiency of Solar Wind Energy Coupling to the Ionosphere, J. Geophys. Res., 117, A7, doi:10.1029/2012JA017627.

Abstract: We present a statistical investigation into the variations of the ionospheric energy coupling efficiencies with the solar wind energy input, the interplanetary magnetic field (IMF) clock angle and the solar wind dynamic pressure. The ionospheric energy coupling efficiencies are defined as the ratios of the ionospheric energy deposition (namely auroral precipitation, Joule heating, and their total) to the solar wind energy input. We find that the ionospheric energy coupling efficiencies decrease exponentially with the solar wind energy input. Moreover, it is the same case under geomagnetic storm conditions. Our results also show that the energy coupling efficiencies are dependent on the IMF clock angle and almost independent of the solar wind dynamic pressure. These results will help us estimate and predict energy transfer from the solar wind to the thermosphere-ionosphere system under extreme space weather conditions, particularly severe geomagnetic storms.

Figure caption: The ionospheric energy coupling efficiencies versus the solar wind energy input for 214 geomagnetic storms. Note that each storm is considered to begin at the first decrease in Dst and end when the Dst has recovered 80% from its lowest value. The exponential fit results are also superimposed on each one.

High Resolution

(3) Guo, J., Feng, T.I. Pulkkinen, E.I. Tanskanen, W. Xu, J. Lei, B.A. Emery, 2012: Auroral electrojets variations caused by recurrent high-speed solar wind streams during the extreme solar minimum of 2008, J. Geophys. Res., 117, A04307, doi:10.1029/2012JA017627.

Abstract: The IMAGE network magnetic measurements are used to investigate the response of the auroral electrojets to the recurrent high-speed solar wind streams (HSSs) during the extreme solar minimum period of 2008. We first compare the global AU/AL indices with the corresponding local IU/IL indices determined from the IMAGE magnetometer chain, and find that the local IMAGE chain can better monitor the activity in MLT-sectors 1230–2230 for IU and 2230-0630 for IL during 2008. In the optimal MLT-sectors, the eastward and westward electrojets and their central latitude reveal clear 9 day periodic variations associated with the recurrent HSSs. For the 9-day perturbations, both the eastward (EEJ) and westward (WEJ) electrojet currents are better correlated with parallel electric field (EPAR) and electron hemispheric power (HPe) than with other forcing parameters. Interestingly, the eastward electrojet EEJ shows good correlations (r > 0.6) with EPAR and HPe only in part of its optimal MLT-sector, roughly 1200–1800, while the westward electrojet WEJ shows good correlations (r < −0.6) with EPAR and HPe in its whole optimal MLT-sector. The poor correlations between the eastward electrojet and EPAR and HPe in the MLT sector 1800–2200 might be attributed to the impact of other magnetosphere-ionosphere coupling processes.

Figure caption: MLT variation of correlation coefficient (r) obtained from the zero-lag cross correlation of band-pass filtered 9-day perturbations in (a) the eastward electrojet current EEJ, (b) the magnetic latitude of EEJ Lat-EEJ, (c) the westward electrojet current WEJ and (d) the magnetic latitude of WEJ Lat-WEJ with the perturbations in various parameters (solar wind velocity V, interplanetary magnetic field B, parallel electric field EPAR, epsilon parameter estimating the solar wind energy input to the magnetosphere, electron hemispheric power HPe and ion hemispheric power HPi) during the entire year of 2008.

High Resolution

(4) Li, Z., J. Guo, F. Wei, X. Feng, B.A. Emery, X. Zhao, 2012: Large ionospheric disturbances during a minor geomagnetic storm on 23 June 2000, Annals of Geophysics, 55, 2, doi:10.4401/ag-5409.

Abstract: We investigate the variations in the ionosphere during a small geomagnetic storm on June 23, 2000, using the total electron content TEC of the Jet Propulsion Laboratory global positioning system, and the ionospheric critical frequency. Large and long-lasting reductions in the daytime electron density were observed at mid-latitudes in the northern hemisphere by ionosondes. These reductions reached 30% to 40% compared to the 27-day median value. At the same time, a transformation from similar large positive storm effects to negative storm effects was observed in the northern hemisphere by the global positioning system receivers. The geomagnetic disturbance was very weak from June 23–25, 2000, as the SYM-H index was >−40 nT and ASY-H was <90 nT. Of note, during this case there were neither long-lasting southward IMF Bz nor strong positive IMF By components. We confirm enhanced energy input from the disturbed solar wind by calculation of the Borovsky, Akasofu and Newell coupling functions, the global auroral precipitation, and the Joule heating from about 1UT on June 23 to 2 UT on June 24. We suggest this enhanced energy input as the main cause of these intense ionospheric storms, although the maximum of the energy input was not large. In addition, we propose that the Newell coupling function might be more suitable for reflecting the energy transfer from the disturbed solar wind to the magnetosphere under weak geomagnetic activity.

Figure caption: Ratios of the total electron content (TEC) for June 23, 2000 with respect to the 27-day TEC show enhanced values in the Northern Hemisphere after 13 UT due to Joule heating effects with increasing equatorward winds that lift the ionosphere to higher altitudes to regions of lower loss rates.

High Resolution

(5) Shim, J.S., M. Kuznetsova, L. Rastätter, M Hesse, D. Bilitza, M Butala, M. Codrescu, B. Emery, B. Foster, T. Fuller-Rowell, J. Huba, A.J. Mannucci, X. Pi, A. Ridley, L. Scherliess, R. W. Schunk, P. Stephens, D. C. Thompson, L. Zhu, D. Anderson, J.L. Chau, J.J. Sojka, and B. Rideout, 2012: CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge for Systematic Assessment of Ionosphere/Thermosphere Models 1: NmF2, hmF2, and Vertical Drift Using Ground Based Observations, Space Weather, 9, S12003, 17pp., doi:10.1029/2011SW000727.

Abstract: Objective quantification of model performance based on metrics helps us evaluate the current state of space physics modeling capability, address differences among various modeling approaches, and track model improvements over time. CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge was initiated in 2009 to assess accuracy of various ionosphere/thermosphere models in reproducing ionosphere and thermosphere parameters. A total of nine events and five physical parameters were selected to compare between model outputs and observations. The nine events included two strong and one moderate geomagnetic storm events from GEM Challenge events and three moderate storms and three quiet periods from the first half of the International Polar Year (IPY) campaign, which lasted for two years from March 2007 to March 2009. The five physical parameters selected were the peak electron density in the F layer (NmF2) and its altitude at hmF2 from incoherent scatter radars (ISRs) and LEO satellites such as CHAMP and COSMIC, vertical F-region ion drifts at Jicamarca near the magnetic equator, and electron and neutral densities along the track of the CHAMP satellite around 400 km. For this study, four different metrics and up to ten models were used. In this paper, we focus on preliminary results of the study using ground based measurements, which include NmF2 and hmF2 from ISRs, and vertical drifts at Jicamarca. The results show that the model performance strongly depends on the type of metrics used, and thus no model is ranked top for all used metrics. The analysis further indicates that performance of the model also varies with latitude and geomagnetic activity level.

Figure caption:Observed (black curves) and modeled (color curves) NmF2 (left panel) and hmf2 (right panel) at Millstone Hill (53 mlat) for a strong storm case, E.2006.348 event (first row) and at EISCAT Svalbard (75 mlat, second row), Sondrestrom (73 mlat, third row), and Poker Flat (65 mlat, fourth row) for E.2007.079 event.

High Resolution

(6) Shim, J. S., M. Kuznetsova, L. Rastätter, D. Bilitza, M. Butala, M. Codrescu, B.A. Emery, B. Foster, T.J. Fuller-Rowell, J. Huba, A.J. Mannucci, X. Pi, A. Ridley, L. Scherliess, R. W. Schunk, J.J. Sojka, P. Stephens, D.C. Thompson, D. Weimer, L. Zhu, and E. Sutton, 2012: CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge for Systematic Assessment of Ionosphere/Thermosphere Models 2: Electron density, Neutral density, NmF2, and hmF2 Using Space Based Observations, Space Weather, 10, S10004, doi:10.1029/2012SW000851.

Abstract: In an effort to quantitatively assess the current capabilities of Ionosphere/Thermosphere (IT) models, an IT model validation study using metrics was performed. This study is a main part of the CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge, which was initiated at the CEDAR workshop in 2009 to better comprehend strengths and weaknesses of models in predicting the IT system, and to trace improvements in ionospheric/thermospheric specification and forecast. For the challenge, two strong geomagnetic storm events, and four moderate storms and three quiet time intervals were selected. For the selected events, we calculated four different scores (i.e., RMS error, prediction efficiency, ratio of the maximum change in amplitudes, and ratio of the maximum amplitudes) to compare the performance of models in reproducing the selected physical parameters such as vertical drifts, electron and neutral densities, NmF2, and hmF2. In this paper, we present the results from comparing modeled values against space-based measurements including NmF2 and hmF2 from the CHAMP and COSMIC satellites, and electron and neutral densities at the CHAMP satellite locations. It is found that the accuracy of models varies with the metrics used, latitude and geomagnetic activity level.

Figure caption: Model ranking for predicting neutral density along the CHAMP trajectory based on RMS error (first row), prediction efficiency (second row), ratio(max-min) (third row), and ratio(max) (fourth row) for low (left column), middle (middle column), and high (right column) latitudes. Squares denote the average values for strong storm cases (E.2005.243 and E.2006.348), circles and triangles indicate the average of moderate storms (E.2001.243, E.2007.091, E.2007.142, and E.2008.059) and the average of quiet periods (E.2007.079, E.2007.190, and E.2007.341). Crosses are the average of the all three geomagnetic activity levels, and the ranking of the performance of the models are arranged by the final average values. The best performing model is located in the extreme left.

High Resolution

(7) Shim, J.S., M. Kuznetsova, L. Rastätter, M. Hesse, D. Bilitza, M. Butala, M. Codrescu, B.A. Emery, B. Foster, T.J. Fuller-Rowell, J. Huba, A.J. Mannucci, X. Pi, A. Ridley, L. Scherliess, R.W. Schunk, J.J. Sojka, P. Stephens, D.C. Thompson, D. Weimer, L. Zhu, D. Anderson, J.L. Chau, and E. Sutton, 2011: Systematic Evaluation of Ionosphere/Thermosphere (IT) Models: CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge (2009–2010), AGU Monographs for the AGU Chapman conference on Modeling the Ionosphere/Thermosphere System, Charleston, SC , (9–12 May 2011), accepted.

Abstract: This looks at the results of the two previous Space Weather papers by Shim et al. in terms of tables instead of figures, so no abstract or figure is included.

Figure caption: WHI's “atypical” solar minimum structure. Left: Composite image of a modeled photospheric magnetic field at the solar surface (saturated at ±1 G), with a selection of magnetic-field lines originating in the plane of the paper, and a color contour of the coronal density (scaled by r 2). Right: Illustration of the large-scale properties of the inner heliosphere out to 1 AU. The isosurface marks the location of Br = 0 and is the location of the heliospheric current sheet. The meridional slice shows radial velocity, and the sphere at 30R⊙ shows the radial magnetic field strength. Figures taken from Riley et al. (2011).

(8) Thompson, B.J., S.E. Gibson, P.C. Schroeder, D.F. Webb, C.N. Arge, M.M. Bisi, G. de Toma, B.A. Emery, A.B. Galvin, D.A. Haber, B.V. Jackson, E.A. Jensen, R.J. Leamon, J. Lei, P.K. Manoharan, M.L. Mays, P.S. McIntosh, G.J.D. Petrie, S.P. Plunkett, L. Qian, P. Riley, S.T. Suess, M. Tokumaru, B.T. Welsch, and T.N. Woods, 2011: A Snapshot of the Sun Near Solar Minimum: The Whole Heliosphere Interval, Solar Physics (Sun-Earth Connection near Solar Minimum topical issue), 274:29–56, doi:10.1007/s11207-011-9891-6.

Abstract: We present an overview of the data and models collected for the Whole Heliosphere Interval (WHI), an international campaign to study the 3-D solar-heliosphere-planetary-geospace connected system near solar minimum. The data and models extend from below the solar photosphere, through interplanetary space, and down to Earth's mesosphere. Nearly 200 people participated in aspects of WHI studies, analyzing and interpreting data from nearly 100 instruments and models in order to elucidate the physics of fundamental heliophysical processes. The papers published in this Topical Issue of Solar Physics: "The Sun-Earth Connection near Solar Minimum: Placing it into Context" represent results from all of WHI's observational regimes, as well as research on the nature of solar minimum in general.

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.