Brief Bio

I am currently a space physics researcher at NASA Goddard Space Flight Center working with the LAMP, petitSat, Artemis, and SPI missions. I started researching waves in Earth's magnetosphere as an undergraduate at Augsburg College with Mark Engebretson using ground based magnetometers in the Arctic and Antarctic. I moved away from waves to focus on geomagnetic storms and substorms during my masters at the University of Colorado Boulder with Dan Baker but returned once more to waves with my PhD at University of Newcastle NSW Australia working under Brian Fraser. My PhD thesis was on Electromagnetic Ion Cyclotron (EMIC) waves during the CRRES mission and their relationship to the plasmasphere and radiation belts. During my postdoc at Dartmouth college I worked on the BARREL mission I have moved down the field line (from a space perspective) and looked at the population of particles lost due to these interactions and their impact on the ionosphere and upper atmosphere.

Today I continue to bounce around the heliosphere and work to connect these regions, processes, and analysis techniques across boundaries.

Research Interests

Current Projects

Positions/Employment

Education

PhD 2012, The University of Newcastle Australia

Masters 2007 CU Boulder 

BA double major Math/Physics graduated from honors & McNair program Augsburg University

Professional Societies

Professional Service

My service to the larger scientific community has come primarily in four parts:
1) Service to mission coordination and mission leadership which include planing and coordinating projects with other agencies and scientists to conduct pioneering projects, developing experimental investigations, and planning the appropriate approach for data acquisition to ensure the right types of data where collected to help resolve outstanding critical scientific problems.
2) Organizing conferences, workshops, sessions, and seminars for the dissemination of presentable results, and to encourage new collaborative research.

3) Service on professional committees which have allowed me the opportunity to help guide the field through recommending future proposal calls, encourage engagement of the scientific community with their political representatives in the hopes of increased funding for the field, and through recognizing some of our outstanding scientific peers.
4) Service to the science community at large and service to my current place of employment through serving as a reviewer for papers and reviewer and panelist for grant opportunities as well as an advocate for the wonderful science completed at my place of employment.

 

Service to Mission coordination and Mission leadership

• Led BARREL collaborations and contact to multiple missions (both US based and interna- tional) including NASA’s Van Allen Probes (US-NASA), Cluster (EU), LOMONOSOV (Russia), ABOVE2 (CA), Firebird (US-UNH and MSU ), AC6 (US-Aerospace Corporation), and CSSWE (US-LASP CU Boulder) as well as with the larger scientific community. I was the BARREL lead for the daily meetings between BARREL and the Van Allen Probe’s instru- ments teams to determine data collection and retrieval during the BARREL campaigns. Other satellite, ground, and CubeSat missions also attended these meetings to determine when they should collect and download data to ensure the correct data type for answering critical science questions for the 2012-2013, 2013-2014, and the August 2015 and 2016 campaigns.
• Helped organize and plan the EFW/BARREL workshop and follow up science meetings, 2013- 2014
• Successfully conceived, planed, and developed experimental investigations and proposed for EISCAT radar time with strong international collaborations for experimental investigations taking advantage of conjugate observations with FIREBIRD, Van Allen Probes, and BARREL for both the 2015 and 2016 campaigns. This work addressed and attempted to resolve scientific problems with identifying the in situ source and scale size of microbursts and other radiation belt electron precipitation events.
• Advocated for the BARREL mission to the larger scientific community and public through near real time dissemination of BARREL progress, observations, and results through the BARREL blog (both one for the public and one for the scientific community), Facebook page, and twitter accounts. December 2012 - present
• Advocated for the BARREL mission to the larger scientific community by presenting and running informal sessions at GEM and AGU on how to use the BARREL data analysis software, how to interpret the BARREL data, and how to identify events vs contamination/noise in the novel BARREL data set.
• Advocated for the BARREL mission to the public through multiple public lectures, a temporary exhibit at a museum, and the creation of a mission short film which was uploaded to the NASA YouTube channel.

Organizing conference/workshops and sessions/seminars

• Program Committee for AGU Chapman conference on ”Scientific Challenges Pertaining to Space Weather Forecasting Including Extremes”
• Chair of an AGU Fall 2018 Session titled ”Quantitative Understanding of Particle Dynamics in Earth’s Radiation Belts”
• Co - convener and chair of an Fall 2018 AGU session titled ”The Application Usability Level (AUL) framework: a standard measure of progress to benefit heliophysics research, and the needs of our society.” with Adam Kellerman, and Jeffery Klenzing.
• Co - convener of an AGU Fall 2018 Session titled ”Challenges in Extreme Space Weather Research: Science, Applications, and Policies” with Denny Oliveira, Noe Lugaz, and Sophie Murray
• Co - convener of an AGU Fall 2018 Session titled ”Application Development in Python for Solar and Space Physics” with Alex DeWolfe and D Aaron Roberts
• Co - convener and chair of an AGU Fall 2018 Union Session titled ”The Challenges of Recog- nizing Implicit Bias in Earth and Space Sciences and Strategies for Minimizing its Impact in the Coming Decades of the AGU” with Hazel Bain and Blair Schneider
• On the Program Committee for the Chapman Conference on Scientific Challenges Pertaining to Space Weather Forecasting including Extremes
• Co-Convener and Chair of a plenary at the TESS meeting in VA, 2018 titled ”Unconscious bias in Space Physics: what is it and what are the solutions?” with K Garcia Sage, N. Vail, Y. Collado-Vega
• • Co - convener and chair of an Fall 2017 AGU session titled ”Assessment of Space Environment Models and Data: Validation Metrics, Frameworks, and Applications” with Adam Kellerman, Katherine Garcia-Sage, and Jeffery Klenzing.
• Organizer for a mini workshop on Assessment of Understanding and Quantifying Progress Toward Science Understanding and Operational Readiness group at the International Forum for Space Weather Capabilities Assessment working group the Sunday before AGU
• Co-lead with Adam Kellerman the Assessment of Understanding and Quantifying Progress Toward Science Understanding and Operational Readiness group at the International Forum for Space Weather Capabilities Assessment Workshop run by the CCMC and LWS. 2016 - present. This includes leading and conducting studies on tracking the progress of our field, development of application usability levels, and development of a framework for dissemination of information including metric and validation techniques and progress.
• On the organizing committee for the Inner Magnetosphere Coupling III meeting held March 2015 at University of California Los Angeles
• Co-lead with Adam Kellerman a special GEM 2017 session on Assessment of Understanding and Quantifying Progress Toward Science Understanding and Operational Readiness
• AGU Fall 2016 session ”Understanding the scale and significance of ULF modulation of higher frequency wave power and energetic particle loss rates” with Aaron Breneman and Chris Colpitts
• • Co-Convener and chair of a joint CEDAR GEM 2016 focus group ”Particle Precipitation and the Effects on Earth’s Atmosphere” with Kyle Murphy, Roger Varney, Stephen Kaeppler, and Allison Jaynes.
• Co-Convener and chair of the Comparative studies of the storm-time inner magnetosphere for the Fall 2015 AGU conference. with Matina Gkioulidou, Drew Turner, and Philip Valek.
• • Co-Convener and chair of the Multi-point Observations in the Inner Magnetosphere: System- wide Understanding of Particle Transport, Energization, and Loss at the Fall 2014 AGU con- ference with Matina Gkioulidou and Drew Turner.
• Ran the Dartmouth Spring Plasma Physics Seminar series, 2013, 2014, 2015
• Chaired session for Fall AGU 2013 Buildup and Dynamics of Ring Current and Radiation Belts at Earth II session.
• Space Physics & Aeronomy Program Committee session liaison for the Outstanding Student Paper Award for sections SM23C, SM24B, SM33A for the Fall AGU 2013 meeting

Professional Organization Membership and Committees

• Serving on the GEM Metrics and Validation Standing Resource Group 2020
• Served on NASA LWS TR&T steering committee 2016
• Member of the American Geophysical Union 2002 - present
  • Serving on the AGU SPA Fellows Committee 2017, 2018, Chair 2019, 2020
  • Serving on the AGU SPA Advocacy committee. 2017 - 2019

Service to Community/institute

• Presented to the AGU Fellows nomination task force on implicit bias and how to write a non-gendered nomination packages. 2017, 2018
• Panelist on the GEM student night panel about Ethics 2017
• Goddard point of contact/organizer for the United States Naval Academy- Goddard summer student research program 2017
• Code 674 point of contact for nugget slides for codes 600, 100, and headquarters, working with Dr. Alex Young 2016 - 2017
• Co-guest Editor of the JGR Energetic Electron Loss and its Impacts on the Atmosphere special issue
• Served on NASA and NSF grant review panels as a write in reviewer, panelist and as chair.
• Active referee for a number of journals including Geophysical Reviews, the Journal of Geophysical Research, Geophysical Research Letters, Annales Geophysicae, Physics of Plasmas, EOS, and Nature Communications.

Awards

• NASA Peer Award for setting up Science Fridays, a new networking event to enable cross pollination of ideas and innovative thinking throughout Goddard, September 2020
• NASA Special Act Award For serving in a critical leadership role as the ARTEMIS Point of Contact in 670, and connecting Heliophysics to the larger efforts at the Center in support of human exploration of the Moon and Moon to Mars.August 2020
• 2018 Editor’s Citation for Excellence in Refereeing for Reviews of Geophysics
• The Aerospace Corporation ”Strategic Imperative Hero pin” for growth 2018
• Goddard Heliophysics Science Division Peer award 2017
• Augsburg First Decade Award 2013 “The First Decade Award is presented to Augsburg graduates of the past 10 years who have made significant progress in their professional achievements and contributions to the community, and in so doing exemplify the mission of the College: to prepare future leaders in service to the world.” - Augsburg College (now Augsburg University)
• Dartmouth Young Visiting Scientist 2012 - 2013.
• Best Science Story at the 10th annual New Year’s Poster Party at NASA Goddard 2017
• Finalist in the Three min. thesis competition, Newcastle University, Callaghan Australia June 2010
• Winner of the Three min. thesis competition in the College round Newcastle University, Callaghan Australia, June 2010
• Voted Best Poster by participating students at Science Research Expo, Newcastle University, Callaghan Australia June 2008
• BA Graduation with honors and from the McNair program, Augsburg College Minneapolis MN May 2003
• Received Outstanding student paper award for poster at Spring 2002 AGU conference
• Student in the McNair Program. A program to prepare minority, underrepresented, and first generation low income students for post graduate studies through research opportunities and other academic activities. Admission is based on academic standing. 2001-2003
• Augsburg Tuition Grant 2002-2003
• President of SPS and President of Unbounded (math club) 2002-2003
• Honorable mention in MCM Mathematical Modeling Contest
• Bev Durkee Mathematics Scholarship 2001-2003
• Leif Sverdrup Physics Scholarship 2000-2003
• Early Advantage Regents’ Scholarship1999-2003
• Augsburg Faculty Leadership Scholarship 1999-2003
• T. Hanwick Science Scholarship 1999-2003
• Prime Church Scholarship 1999-2003
• Prime Augsburg match 1999-2003

Publications

Refereed

Klenzing, J., A. J. Halford, A. Kellerman, and B. Thompson. 2023. "Using Application Usability Levels to support tracking the health of Heliophysics." Frontiers in Astronomy and Space Sciences, 10: [10.3389/fspas.2023.1144053]

Halford, A. J., A. G. Burrell, M. W. Liemohn, et al. M. Jones, A. Maute, T. I. Pulkkinen, C. M. Bard, R. M. McGranaghan, L. B. Wilson, R. C. Allen, C. Dong, S. K. Vines, L. Wang, N. Turner, K. Garcia-Sage, K. Mandt, and J. Klenzing. 2023. "Cultivating a culture of inclusivity in heliophysics." Frontiers in Physics, 11: [10.3389/fphy.2023.1061683]

Schonfeld, S. J., W. D. Pesnell, J. L. Verniero, et al. Y. J. Rivera, A. J. Halford, S. K. Vines, and S. A. Spitzer. 2023. "Expanding the deep space network to support the heliophysics system observatory." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1051527]

Klenzing, J., A. J. Halford, G. Liu, et al. J. M. Smith, Y. Zhang, K. Zawdie, N. Maruyama, R. Pfaff, and R. L. Bishop. 2023. "A system science perspective of the drivers of equatorial plasma bubbles." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1064150]

Narock, A., C. Bard, B. J. Thompson, et al. A. J. Halford, R. M. McGranaghan, D. da Silva, B. Kosar, and M. Shumko. 2022. "Supporting responsible machine learning in heliophysics." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1064233]

Halford, A. J., A. G. Burrell, E. Yizengaw, et al. V. Bothmer, B. A. Carter, J. C. Raymond, A. Maute, M. Samara, N. Maruyama, and L. R. Alves. 2022. "Thoughts from a past AGU SPA fellows committee." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1054343]

Jones, M., A. G. Burrell, J. L. Gannon, et al. A. J. Halford, A. N. Jaynes, A. Maute, and K. Thiero. 2022. "Recommendations on simple but transformative diversity, equity, and inclusion measures in Heliophysics over the next decade." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1062970]

Halford, A. J., T. Y. Chen, and L. Rastaetter. 2022. "Data needs to be a priority." Frontiers in Physics, 10: [10.3389/fphy.2022.1061681]

Klenzing, J., J. M. Smith, A. J. Halford, J. D. Huba, and A. G. Burrell. 2022. "sami2py—Overview and applications." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1066480]

Ledvina, V. E., E. Palmerio, R. M. McGranaghan, et al. A. J. Halford, A. Thayer, L. Brandt, E. A. MacDonald, A. Bhaskar, C. Dong, I. Altintas, J. Colliander, M. Jin, R. N. Jain, S. Chatterjee, Z. Shaikh, N. A. Frissell, T. Y. Chen, R. J. French, B. Isola, S. W. McIntosh, E. I. Mason, P. Riley, T. Young, W. Barkhouse, M. D. Kazachenko, M. Snow, D. S. Ozturk, S. G. Claudepierre, F. Di Mare, A. Witteman, and J. Kuzub. 2022. "How open data and interdisciplinary collaboration improve our understanding of space weather: A risk and resiliency perspective." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1067571]

Breneman, A. W., J. R. Wygant, S. Tian, et al. C. A. Cattell, S. A. Thaller, K. Goetz, E. Tyler, C. Colpitts, L. Dai, K. Kersten, J. W. Bonnell, S. D. Bale, F. S. Mozer, P. R. Harvey, G. Dalton, R. E. Ergun, D. M. Malaspina, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky, C. Smith, R. H. Holzworth, S. Lejosne, O. Agapitov, A. Artemyev, M. K. Hudson, R. J. Strangeway, D. N. Baker, X. Li, J. Albert, J. C. Foster, P. J. Erickson, C. C. Chaston, I. Mann, E. Donovan, C. M. Cully, V. Krasnoselskikh, J. B. Blake, R. Millan, and A. J. Halford. 2022. "The Van Allen Probes Electric Field and Waves Instrument: Science Results, Measurements, and Access to Data." Space Science Reviews, 218 (8): 69 [10.1007/s11214-022-00934-y]

Manweiler, J. W., A. Breneman, J. Niehof, et al. B. Larsen, G. Romeo, G. Stephens, A. Halford, C. Kletzing, L. E. Brown, H. Spence, G. Reeves, R. Friedel, S. Smith, R. Skoug, B. Blake, D. Baker, S. Kanekal, V. Hoxie, A. Jaynes, J. Wygant, J. Bonnell, D. Crawford, M. Gkioulidou, L. J. Lanzerotti, D. G. Mitchell, A. Gerrard, A. Ukhorskiy, T. Sotirelis, R. J. Barnes, R. Millan, and B. Harris. 2022. "Science of the Van Allen Probes Science Operations Centers." Space Science Reviews, 218 (8): 66 [10.1007/s11214-022-00919-x]

Zawdie, K., A. Belehaki, M. Burleigh, et al. M.-Y. Chou, M. S. Dhadly, K. Greer, A. J. Halford, D. Hickey, P. Inchin, S. R. Kaeppler, J. Klenzing, V. L. Narayanan, F. Sassi, M. Sivakandan, J. M. Smith, N. Zabotin, M. D. Zettergren, and S.-R. Zhang. 2022. "Impacts of acoustic and gravity waves on the ionosphere." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1064152]

Murphy, K. R., I. J. Rae, A. J. Halford, et al. M. Engebretson, C. T. Russell, J. Matzka, M. G. Johnsen, D. K. Milling, I. R. Mann, A. Kale, Z. Xu, M. Connors, V. Angelopoulos, P. Chi, and E. Tanskanen. 2022. "GMAG: An open-source python package for ground-based magnetometers." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1005061]

Shumko, M., D. Chaddock, B. Gallardo-Lacourt, et al. E. Donovan, E. L. Spanswick, A. J. Halford, I. Thompson, and K. R. Murphy. 2022. "AuroraX, PyAuroraX, and aurora-asi-lib: A user-friendly auroral all-sky imager analysis framework." Frontiers in Astronomy and Space Sciences, 9: [10.3389/fspas.2022.1009450]

Halford, A. J., K. Garcia‐Sage, I. R. Mann, D. L. Turner, and A. W. Breneman. 2022. "The Effect of Compression Induced Chorus Waves on 10s to 100s eV Electron Precipitation." Geophysical Research Letters, (Accepted) [10.1029/2022gl098842]

Elliott, S. S., A. W. Breneman, C. Colpitts, et al. J. M. Pettit, C. A. Cattell, A. J. Halford, M. Shumko, J. Sample, A. T. Johnson, Y. Miyoshi, Y. Kasahara, C. M. Cully, S. Nakamura, T. Mitani, T. Hori, I. Shinohara, K. Shiokawa, S. Matsuda, M. Connors, M. Ozaki, and J. Manninen. 2022. "Quantifying the Size and Duration of a Microburst‐Producing Chorus Region on 5 December 2017." Geophysical Research Letters, 49 (15): [10.1029/2022gl099655]

O'Brien, T. P., J. C. Green, A. J. Halford, et al. B. P. Kwan, S. G. Claudepierre, and L. G. Ozeke. 2022. "Drift Phase Structure Implications for Radiation Belt Transport." Journal of Geophysical Research: Space Physics, 127 (8): [10.1029/2022ja030331]

Burrell, A. G., M. Jones, A. Halford, K. Zawdie, and J. Coxon. 2021. "Bypassing the bias." Astronomy & Geophysics, 62 (5): 5.28-5.29 [10.1093/astrogeo/atab090]

Shumko, M., B. Gallardo‐Lacourt, A. J. Halford, et al. J. Liang, L. W. Blum, E. Donovan, K. R. Murphy, and E. Spanswick. 2021. "A Strong Correlation Between Relativistic Electron Microbursts and Patchy Aurora." Geophysical Research Letters, 48 (18): [10.1029/2021gl094696]

Breneman, A. W., A. J. Halford, R. M. Millan, et al. L. A. Woodger, X. Zhang, J. K. Sandhu, L. Capannolo, W. Li, Q. Ma, C. M. Cully, K. R. Murphy, T. Brito, and S. S. Elliott. 2020. "Driving of Outer Belt Electron Loss by Solar Wind Dynamic Pressure Structures: Analysis of Balloon and Satellite Data." Journal of Geophysical Research: Space Physics, 125 (12): [10.1029/2020ja028097]

Shumko, M., A. T. Johnson, T. P. O'Brien, et al. D. L. Turner, A. D. Greeley, J. G. Sample, J. B. Blake, L. W. Blum, and A. J. Halford. 2020. "Statistical Properties of Electron Curtain Precipitation Estimated With AeroCube‐6." Journal of Geophysical Research: Space Physics, 125 (12): [10.1029/2020ja028462]

Klenzing, J., R. Davidson, S. Jones, et al. C. Martinis, K. Zawdie, G. Earle, J. Smith, A. Halford, S. Noel, N. Paschalidis, R. Pfaff, and E. Robertson. 2020. "The petitSat Mission – Science Goals and Instrumentation." Advances in Space Research, 66 (1): 107-115 [10.1016/j.asr.2019.12.013]

Remya, B., D. Sibeck, J. Ruohoniemi, et al. B. Kunduri, A. Halford, G. Reeves, and R. Reddy. 2020. "Association between EMIC wave occurrence and enhanced convection periods during ion injections." Geophysical Research Letters, 2019GL085676 (In Press) [10.1029/2019gl085676]

Brito, T. V., A. J. Halford, and S. R. Elkington. 2020. "Ultralow frequency-wave induced losses." The Dynamic Loss of Earth's Radiation Belts, 29-48 [10.1016/b978-0-12-813371-2.00002-0]

Cid, C., A. Guerrero, E. Saiz, A. Halford, and A. Kellerman. 2019. "Developing the LDi and LCi geomagnetic indices, an example of application of the AULs framework." Space Weather, 2019SW002171 [10.1029/2019sw002171]

Halford, A. J., A. C. Kellerman, K. Garcia-Sage, et al. J. Klenzing, B. A. Carter, R. M. McGranaghan, T. Guild, C. Cid, C. J. Henney, N. Y. Ganushkina, A. G. Burrell, M. Terkildsen, D. T. Welling, S. A. Murray, K. Leka, J. P. McCollough, B. J. Thompson, A. Pulkkinen, S. F. Fung, S. Bingham, M. M. Bisi, M. W. Liemohn, B. M. Walsh, and S. K. Morley. 2019. "Application Usability Levels: A Framework for Tracking Project Product Progress." J. Space Weather Space Clim. , 9: A34 [https://doi.org/10.1051/swsc/2019030 ]

Bingley, L., V. Angelopoulos, D. Sibeck, X. Zhang, and A. Halford. 2019. "The Evolution of a Pitch‐Angle “Bite‐Out” Scattering Signature Caused by EMIC Wave Activity: A Case Study." Journal of Geophysical Research: Space Physics, 124 (7): 5042-5055 [10.1029/2018ja026292]

Lessard, M. R., K. Paulson, H. E. Spence, et al. C. Weaver, M. J. Engebretson, R. Millan, L. Woodger, A. Halford, R. Horne, C. J. Rodger, and A. Hendry. 2019. "Generation of EMIC Waves and Effects on Particle Precipitation During a Solar Wind Pressure Intensification with B z > 0." Journal of Geophysical Research: Space Physics, 2019JA026477 [10.1029/2019ja026477]

Medeiros, C., V. M. Souza, L. E. Vieira, et al. D. G. Sibeck, A. J. Halford, S.-B. Kang, L. A. Silva, L. R. Alves, J. P. Marchezi, R. S. Dallaqua, P. R. Jauer, M. Rockenbach, O. Mendes, M. V. Alves, A. D. Lago, M.-C. Fok, S. G. Kanekal, D. N. Baker, and C. A. Kletzing. 2019. "On the Contribution of EMIC Waves to the Reconfiguration of the Relativistic Electron Butterfly Pitch Angle Distribution Shape on 2014 September 12—A Case Study." The Astrophysical Journal, 872 (1): 36 [10.3847/1538-4357/aaf970]

Angelopoulos, V., P. Cruce, A. Drozdov, et al. E. W. Grimes, N. Hatzigeorgiu, D. A. King, D. Larson, J. W. Lewis, J. M. McTiernan, D. A. Roberts, C. L. Russell, T. Hori, Y. Kasahara, A. Kumamoto, A. Matsuoka, Y. Miyashita, Y. Miyoshi, I. Shinohara, M. Teramoto, J. B. Faden, A. J. Halford, M. McCarthy, R. M. Millan, J. G. Sample, D. M. Smith, L. A. Woodger, A. Masson, A. A. Narock, K. Asamura, T. F. Chang, C.-Y. Chiang, Y. Kazama, K. Keika, S. Matsuda, T. Segawa, K. Seki, M. Shoji, S. W. Tam, N. Umemura, B.-J. Wang, S.-Y. Wang, R. Redmon, J. V. Rodriguez, H. J. Singer, J. Vandegriff, S. Abe, M. Nose, A. Shinbori, Y.-M. Tanaka, S. UeNo, L. Andersson, P. Dunn, C. Fowler, J. S. Halekas, T. Hara, Y. Harada, C. O. Lee, R. Lillis, D. L. Mitchell, M. R. Argall, K. Bromund, J. L. Burch, I. J. Cohen, M. Galloy, B. Giles, A. N. Jaynes, O. Le Contel, M. Oka, T. D. Phan, B. M. Walsh, J. Westlake, F. D. Wilder, S. D. Bale, R. Livi, M. Pulupa, P. Whittlesey, A. DeWolfe, B. Harter, E. Lucas, U. Auster, J. W. Bonnell, C. M. Cully, E. Donovan, R. E. Ergun, H. U. Frey, B. Jackel, A. Keiling, H. Korth, J. P. McFadden, Y. Nishimura, F. Plaschke, P. Robert, D. L. Turner, J. M. Weygand, R. M. Candey, R. C. Johnson, T. Kovalick, M. H. Liu, R. E. McGuire, A. Breneman, K. Kersten, and P. Schroeder. 2019. "The Space Physics Environment Data Analysis System (SPEDAS)." Space Science Reviews, 215 (1): 9 [10.1007/s11214-018-0576-4]

Rudd, J., D. Oliveira, A. Bhaskar, and A. Halford. 2019. "How do interplanetary shock impact angles control the size of the geoeffective magnetosphere?" Advances in Space Research, 61 (1): 317-326 [10.1016/j.asr.2018.09.013]

Burrell, A. G., A. Halford, J. Klenzing, et al. R. A. Stoneback, S. K. Morley, A. M. Annex, K. M. Laundal, A. C. Kellerman, D. Stansby, and J. Ma. 2018. "Snakes on a Spaceship—An Overview of Python in Heliophysics." Journal of Geophysical Research: Space Physics, 123 (12): 2018JA025877 [10.1029/2018ja025877]

Chaston, C. C., J. W. Bonnell, A. J. Halford, et al. G. D. Reeves, D. N. Baker, C. A. Kletzing, and J. R. Wygant. 2018. "Pitch Angle Scattering and Loss of Radiation Belt Electrons in Broadband Electromagnetic Waves." Geophysical Research Letters, 45 (18): 9344-9352 [10.1029/2018gl079527]

Gunawan, B., E. A. Bering, R. Talbot, et al. C. Glennie, D. Rodrigues, J. Chen, M. Alozie, C. Behrend, C. Bias, A. Ehteshami, A. Fenton, M. L. Greer, J. Lehnen, A. Martinez, S. Mathur, M. Medellin, T. Nguyen, M. Nowling, D. Perez, M. Pham, M. Pina, I. Porat, J. Prince, G. Thomas, B. Velasquez, L. Victor, R. Gamblin, J. Subhlok, W. Harrison, A. Hamza, B. J. Dunbar, N. Moelders, D. Hampton, R. Millan, and A. J. Halford. 2018. "NASA and University of Houston’s Approach in Engaging and Developing Undergraduate Students’ Skills Through Undergraduate Student Instrumentation Project." 2018 AIAA SPACE and Astronautics Forum and Exposition, [10.2514/6.2018-5139]

Remya, B., D. G. Sibeck, A. J. Halford, et al. K. R. Murphy, G. D. Reeves, H. J. Singer, J. R. Wygant, G. Farinas Perez, and S. A. Thaller. 2018. "Ion Injection Triggered EMIC Waves in the Earth's Magnetosphere." Journal of Geophysical Research: Space Physics, 123 (6): 4921-4938 [10.1029/2018ja025354]

Oliveira, D. M., D. Arel, J. Raeder, et al. E. Zesta, C. M. Ngwira, B. A. Carter, E. Yizengaw, A. J. Halford, B. T. Tsurutani, and J. W. Gjerloev. 2018. "Geomagnetically induced currents caused by interplanetary shocks with different impact angles and speeds." Space Weather, 16 (6): 636-647 [10.1029/2018sw001880]

Jonathan Rae, I., K. R. Murphy, C. E. Watt, et al. A. J. Halford, I. R. Mann, L. G. Ozeke, D. G. Sibeck, M. A. Clilverd, C. J. Rodger, A. W. Degeling, C. Forsyth, and H. J. Singer. 2018. "The Role of Localized Compressional Ultra-low Frequency Waves in Energetic Electron Precipitation." Journal of Geophysical Research: Space Physics, [10.1002/2017ja024674]

Greer, M. L., E. A. Bering, R. Talbot, et al. B. Dunbar, C. Glennie, D. Rodrigues, J. Chen, M. Alozie, C. Behrend, C. Bias, A. Ehteshami, A. Fenton, B. Gunawan, J. Lehnen, A. Martinez, S. Mathur, M. Medellin, T. Nguyen, T. V. Nguyen, M. Nowling, D. Perez, M. Pham, M. Pina, I. Porat, J. Prince, G. Thomas, B. Velasquez, L. Victor, R. Gamblin, N. Moelders, D. Hampton, R. Millan, and A. Halford. 2017. "The Undergraduate Student Instrumentation Project: A Foray into Instrument Design, Payload Fabrication, and Project Management." AIAA SPACE and Astronautics Forum and Exposition, [10.2514/6.2017-5136]

Clilverd, M. A., C. J. Rodger, M. McCarthy, et al. R. Millan, L. W. Blum, N. Cobbett, J. B. Brundell, D. Danskin, and A. J. Halford. 2017. "Investigating energetic electron precipitation through combining ground‐based and balloon observations." Journal of Geophysical Research: Space Physics, 122 (1): 534-546 [10.1002/2016ja022812]

Zhang, J., A. J. Halford, A. A. Saikin, et al. C.-L. Huang, H. E. Spence, B. A. Larsen, G. D. Reeves, R. M. Millan, C. W. Smith, R. B. Torbert, W. S. Kurth, C. A. Kletzing, J. B. Blake, J. F. Fennel, and D. N. Baker. 2016. "EMIC waves and associated relativistic electron precipitation on 25-26 January 2013." Journal of Geophysical Research: Space Physics, 121 (11): 11,086-11,100 [10.1002/2016ja022918]

Halford, A. J., B. J. Fraser, S. K. Morley, S. R. Elkington, and A. A. Chan. 2016. "Dependence of EMIC wave parameters during quiet, geomagnetic storm, and geomagnetic storm phase times." Journal of Geophysical Research: Space Physics, 121 (7): 6277–6291 [10.1002/2016ja022694]

Halford, A. J., S. L. McGregor, M. K. Hudson, R. M. Millan, and B. T. Kress. 2016. "BARREL observations of a solar energetic electron and solar energetic proton event." Journal of Geophysical Research: Space Physics, 121 (5): 4205-4216 [10.1002/2016ja022462]

Carter, B. A., E. Yizengaw, R. Pradipta, et al. A. J. Halford, R. Norman, and K. Zhang. 2015. "Interplanetary shocks and the resulting geomagnetically induced currents at the equator." Geophysical Research Letters, 42 (16): 6554-6559 [10.1002/2015gl065060]

Blum, L. W., A. Halford, R. Millan, et al. J. W. Bonnell, J. Goldstein, M. Usanova, M. Engebretson, M. Ohnsted, G. Reeves, H. Singer, M. Clilverd, and X. Li. 2015. "Observations of coincident EMIC wave activity and duskside energetic electron precipitation on 18-19 January 2013." Geophysical Research Letters, 42 (14): 5727-5735 [10.1002/2015gl065245]

Breneman, A. W., A. Halford, R. Millan, et al. M. McCarthy, J. Fennell, J. Sample, L. Woodger, G. Hospodarsky, J. R. Wygant, C. A. Cattell, J. Goldstein, D. Malaspina, and C. A. Kletzing. 2015. "Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss." Nature, 523 (7559): 193-195 [10.1038/nature14515]

Woodger, L. A., A. J. Halford, R. M. Millan, et al. M. P. McCarthy, D. M. Smith, G. S. Bowers, J. G. Sample, B. R. Anderson, and X. Liang. 2015. "A summary of the BARREL campaigns: Technique for studying electron precipitation." Journal of Geophysical Research: Space Physics, 120 (6): 4922-4935 [10.1002/2014ja020874]

Brito, T., M. K. Hudson, B. Kress, et al. J. Paral, A. Halford, R. Millan, and M. Usanova. 2015. "Simulation of ULF wave-modulated radiation belt electron precipitation during the 17 March 2013 storm." Journal of Geophysical Research: Space Physics, 120 (5): 3444-3461 [10.1002/2014ja020838]

Halford, A. J., S. L. McGregor, K. R. Murphy, et al. R. M. Millan, M. K. Hudson, L. A. Woodger, C. A. Cattel, A. W. Breneman, I. R. Mann, W. S. Kurth, G. B. Hospodarsky, M. Gkioulidou, and J. F. Fennell. 2015. "BARREL observations of an ICME-shock impact with the magnetosphere and the resultant radiation belt electron loss." Journal of Geophysical Research: Space Physics, 120 (4): 2557-2570 [10.1002/2014ja020873]

Halford, A. J., B. J. Fraser, and S. K. Morley. 2015. "EMIC waves and plasmaspheric and plume density: CRRES results." Journal of Geophysical Research: Space Physics, 120 (3): 1974-1992 [10.1002/2014ja020338]

Blum, L. W., Q. Schiller, X. Li, et al. R. Millan, A. Halford, and L. Woodger. 2013. "New conjunctive CubeSat and balloon measurements to quantify rapid energetic electron precipitation." Geophysical Research Letters, 40 (22): 5833-5837 [10.1002/2013gl058546]

Millan, R. M., M. P. McCarthy, J. G. Sample, et al. D. M. Smith, L. D. Thompson, D. G. McGaw, L. A. Woodger, J. G. Hewitt, M. D. Comess, K. B. Yando, A. X. Liang, B. A. Anderson, N. R. Knezek, W. Z. Rexroad, J. M. Scheiman, G. S. Bowers, A. J. Halford, A. B. Collier, M. A. Clilverd, R. P. Lin, and M. K. Hudson. 2013. "The Balloon Array for RBSP Relativistic Electron Losses (BARREL)." Space Science Reviews, 179 (1-4): 503-530 [10.1007/s11214-013-9971-z]

Halford, A. J., B. J. Fraser, and S. K. Morley. 2010. "EMIC wave activity during geomagnetic storm and nonstorm periods: CRRES results." Journal of Geophysical Research: Space Physics, 115 (A12): [10.1029/2010ja015716]

Engebretson, M. J., J. L. Posch, A. J. Halford, et al. G. A. Shelburne, A. J. Smith, M. Spasojević, U. S. Inan, and R. L. Arnoldy. 2004. "Latitudinal and seasonal variations of quasiperiodic and periodic VLF emissions in the outer magnetosphere." Journal of Geophysical Research, 109 (A5): A05216 [10.1029/2003ja010335]

Talks, Presentations and Posters

Invited

Selected Public Outreach