Michael J. Buonsanto Memorial Lecture Series

The 21st annual Michael J. Buonsanto Memorial Lecture was presented by Alan Burns, of the High Altitude Observatory at NCAR. It is available on the Haystack YouTube channel.

Buonsanto Lecture 2020

The Buonsanto lecture topic this year was “Geomagnetic activity effects on thermospheric composition as seen by GOLD.”

Date: Thursday, 5 November 2020
Time: 3:00 p.m. ET (Eastern time


Geomagnetic storms cause large changes in the ionosphere. There are both increases (positive storm effects) and decreases (negative storm effects) in electron density at the F2 peak and in the topside ionosphere (hence in TEC too). Over 60 years ago, Seaton suggested that thermospheric neutral composition might be the source of the negative geomagnetic storm effects in the ionosphere. Since that time, much progress has been made in determining the nature and causes of these composition changes. However, this work has been hampered until recently by the inability to separate longitude, universal time and local time effects. Because of the large number of ways that geomagnetic storms can vary from each other, this results in an observational understanding of storm-time composition changes that is essentially climatological, much as it has been for many years. Some insight into the weather of geomagnetic storms has been gained from models, but this too is limited by the way that the geomagnetic drivers are input into these models. Understanding geomagnetic effects on composition during geomagnetically quiet times has proved to be even more of a challenge. The Global-scale Observations of the Limb and Disk (GOLD) mission is allowing a new look at these composition changes, and ties them to temperature as well. However, few geomagnetic storms have occurred since GOLD started observing, so our early work has concentrated of the effects of weaker geomagnetic activity on thermospheric composition. Surprisingly, these effects have proven to be large. In this presentation, I will describe why composition changes during geomagnetic storms and then apply this understanding to the “quiet-time” changes seen by GOLD and to some of the changes in TEC.

About the speaker

Alan Burns graduated with a PhD from the University of Canterbury in 1986. He then became  a Post Doctoral Research Fellow at the Space Physics Research Laboratory at the University of Michigan under the supervision of Tim Killeen. He moved from SPRL to the High Altitude Observatory from the University of Michigan in 2000, where he remains. He is the author or co-author of over 170 papers and numerous presentations. He was Associate Editor of J. Atmos. Terr. Phys. from 2000–2007, and of J. Geophys. Res. from 2011–2015. His initial work was directed at studying changes in thermospheric composition during storms. This has subsequently branched out into a number of areas including quiet-time composition, the thermal structure of the upper atmosphere in both quiet- and storm-time, the ionospheric response to storms, annual and Weddel Sea Anomaly forcing, the effects of Corotating Interaction regions versus Coronal Mass ejections on the thermosphere and ionosphere, and the topside ionosphere, to name a few. 

For a list of past speakers, please see the Buonsanto Memorial Lecture Series archive.

About the series

Dr. Michael J. Buonsanto (1952–1999) was a key member of the Atmospheric Sciences Group at MIT Haystack Observatory from January 1988 until his sudden and untimely death on 21 October 1999. As an MIT Principal Research Scientist, he made many important scientific contributions to studies of the Earth’s upper atmosphere, and was an outstanding and cherished colleague, mentor, and friend. In his honor, Haystack Observatory has established an annual memorial lecture on space science topics at the forefront of the atmospheric science research field.

At Haystack, Buonsanto specialized in mid-latitude physics and chemistry of the upper atmosphere and effects of magnetic storms, significantly advancing these fields worldwide through numerous publications done in wide-ranging collaborations with members of the international aeronomy and space physics community. He was the driving force behind the highly productive US Coupling Energetics and Dynamics of Atmospheric Regions (CEDAR) program’s STORM working group, and was elected to the CEDAR Science Steering Committee. Despite his short career, Michael’s scientific output was prodigious, authoring over 70 refereed scientific articles. He was the single author on 13 of these articles, most notably his 1999 ionospheric storms review paper which continues to be highly referenced today with 650+ citations.

Michael J. Buonsanto (1952–1999)
Michael J. Buonsanto (1952–1999)

Buonsanto was a graduate of Northwestern University and received Masters degrees in Education and Astronomy from Tufts University and Boston University, respectively, working with Professor Michael Mendillo. He earned his PhD in Engineering from the University of Auckland (New Zealand) under Professor John Titheridge, and devoted most of the 1980s to religious education, teaching, and ionospheric research while living among the people of the Fiji Islands. Michael’s career was characterized by intellectual honesty along with a deep openness and willingness to work with and educate others. Students from middle school to graduate school reaped numerous benefits from his dedicated guidance and supervision. Postdoctoral researchers, visiting scholars, and fellow researchers spanning the globe (whose only contact with him was sometimes online) received his full attention and careful assistance with the datasets needed to further their research.

Buonsanto was an excellent and organized scientist whose many seminal contributions span a wide range of topics in ionospheric physics. His untimely death was a great loss to the community. Michael’s work continues today through the lasting international impacts of his insightful physics, enduring journal articles, research by former students, and in the efforts of his dedicated scientific colleagues.