Atmospheric electricity

Research on Terrestrial Gamma-ray Flashes (TGFs), gamma-ray glows, and related high-energy atmospheric phenomena related to thunderclouds and lightning discharge.

The main questions we want to answer:

• how are TGFs produced?
• what is the relation between high-energy processes in the atmosphere and the lightning discharge?
• do TGFs and related high-energy phenomena have any impact on atmospheric chemistry and dynamics?

The tools we use:

• data from the Airborne Lightning Observatory for FEGS and TGFs (ALOFT) flight campaign
• data from the Atmosphere-Space Interactions Monitor (ASIM) mission onboard the International Space Station (ISS)
• data from the Astrorivelatore Gamma a Immagini LEggero (AGILE) mission
• dedicated laboratory experiments and modelling

High-energy astrophysics

Research on cosmic Gamma-Ray Bursts (GRB).

The main question we want to answer:

• how can we use timing information to extract properties of the GRB progenitors?
• can we exploit the timing and spectral performance of ASIM for GRB science?

The tools we use:

• data from the Atmosphere-Space Interactions Monitor (ASIM) mission onboard the International Space Station (ISS)

High-energy detectors and systems

• we have built the gamma-ray detector for the ALOFT flight campaign
• we are building the Electrical Ground Support Equipment (EGSE) for X- and Gamma-ray Imaging Sensor (XGIS) of the Transient High-Energy Sky and Early Universe Surveyor (THESEUS), a medium-class mission candidate for the European Space Agency, currently in Phase A.

The latest news on my research, on the University of Bergen Website (Feb. 2025) 

Our work published in Nature in October 2024 has been picked up by more than 160 international media.

I regularly contributed to the news posted on the website of the Birkeland Centre for Space Science (2013 - 2023):

• August 2021: news on the new project funded by NFR
• June 2021: news on the ongoing collaboration between Italy and Norway on TGF science
• August 2019: news on the first meeting of the ISSI Team I coordinated (2019 - 2022)
• May 2019: news on the TGF International Research School

I also prepared the text for the BCSS annual report in the years 2017-2020, concerning the section related to Hard Radiation from Thunderstorms (all Annual Reports available from the BCSS homepage)

In June 2021 I prepared the text (in Italian) for the news on the ongoing collaboration between Italy and Norway on TGF, which has been posted on the website of the Italian Embassy in Oslo and on its social media accounts, and on the website of the Italian Ministry of Foreign Affairs dedicated to scientific diplomacy.

I also contributed, both with text and interviews, to the preparation of news (in Italian) published on ‘Media INAF’, the online public outreach journal of the Italian National Institute for Astrophysics:

• December 2019: news with interview on the first published results from ASIM
• March 2018: news with interview on the ASIM mission close to launch
• November 2017: news on a recent detection of a TGF from ground
• September 2010: news on the first localization of TGFs in gamma-rays (I am first author of the paper)

Bachelor / Master course responsibilities:

• 2024 –          PHYS251 The Near Earth Space, department of Physics and Technology, University of Bergen, Norway (main course responsible, 10 ECTS)
• 2016 –           PHYS113 Mechanics II and Thermodynamics, department of Physics and Technology, University of Bergen, Norway (main course responsible, 10 ECTS)

Supervisor / co-supervisor of the following PhD Thesis:

• Ingrid Bjørge-Engeland, The connection between lightning currents, TGF intensities and Elves, University of Bergen, Norway, 2024.
• Chris A. Skeie, Aircraft and spacecraft observations of high-energy radiation associated with lightning leaders, University of Bergen, Norway, 2022.
• Anders Lindanger, Spectral Analysis of Terrestrial Gamma-ray Flashes and Their Connection to Lightning Discharges, University of Bergen, Norway, 2022.
• Carolina Maiorana, Characteristics and Meteorological Environment of Terrestrial Gamma-ray Flashes, University of Bergen, Norway, 2021.
• Alessandra Tiberia, High-energy radiation from thunderclouds: on the relationships between terrestrial gamma-ray flashes and cloud structure, University of Ferrara, Italy, 2019.
• Alessandro Ursi, Short-duration gamma-ray transients Detection of Short Hard Bursts and Terrestrial Gamma-ray Flashes by the AGILE satellite, Sapienza University of Rome, Italy, 2016.

Supervisor of the following Master Thesis:

• Andreas Ramsli, Observation of cosmic Gamma-Ray Bursts with the ASIM mission onboard the International Space Station, University of Bergen, Norway, 2023.
• Anders Lindanger, Search for Terrestrial Gamma-ray Flashes in AGILE data by correlation with ground-based lightning measurements, University of Bergen, Norway, 2018.
• Alessandro Ursi, A search for Terrestrial Gamma-Ray Flashes in the BeppoSAX Gamma-Ray Burst Monitor data archive, University of Ferrara, Italy, 2013.

Contribution to research schools:

• 2024   invited teacher at the 1^st International School on Satellite Meteorology (ISSM), 2-6 Sep. 2024, Naples, Italy.
• 2019    Co-organizer and teacher at the Birkeland Centre Research School “Atmospheric Electricity and Hard Radiation from Thunderclouds”, University of Bergen, Norway

I am coauthor of 142 refereed publications, with an H-Index of 40 (Web of Science, accessed 12/09/2024).

My top research publications are the following

1. M. Marisaldi, N. Østgaard, A. Mezentsev, et al. (2024), Highly dynamic gamma-ray emissions are common in tropical thunderclouds, Nature, 634, 57, DOI: 10.1038/s41586-024-07936-6.
2. N. Østgaard, A. Mezentsev, M. Marisaldi, et al. (2024), Flickering Gamma-Ray Flashes, the Missing Link between Gamma Glows and TGFs, Nature, 634, 53, DOI: 10.1038/s41586-024-07893-0.
3. A. Castro-Tirado, N. Østgaard, E. Gögüs, et al. (2021), Very-high-frequency oscillations in the main peak of a magnetar giant flare, Nature 600, https://doi.org/10.1038/s41586-021-04101-1 
4. M. Marisaldi, et al. (2019), On the high-energy spectral component and fine time structure of terrestrial gamma-ray flashes, J. Geophys. Res. (Atmospheres), 124. https://doi.org/10.1029/2019JD030554 
5. M. Marisaldi, et al. (2015), Enhanced detection of terrestrial gamma-ray flashes by agile. Geophys. Res. Lett., 42(21):9481–9487, https://doi.org/10.1002/2015GL066100 
6. M. Marisaldi, F. Fuschino, M. Tavani, et al. (2014) Properties of terrestrial gamma ray flashes detected by AGILE MCAL below 30 MeV. J. Geophys. Res. (Space Physics), 119:1337–1355, https://doi.org/10.1002/2013JA019301 
7. M. Tavani, M. Marisaldi, C. Labanti, et al. (2011), Terrestrial Gamma-Ray Flashes as Powerful Particle Accelerators. Physical Review Letters, 106(1):018501, https://doi.org/10.1103/PhysRevLett.106.018501 
8. M. Marisaldi, et al. (2010), Gamma-Ray Localization of Terrestrial Gamma-Ray Flashes. Physical Review Letters, 105(12):128501, https://doi.org/10.1103/PhysRevLett.105.128501 
9. M. Marisaldi, et al. (2010), Detection of terrestrial gamma ray flashes up to 40 MeV by the AGILE satellite. J. Geophys. Res. (Space Physics), 115:0, https://doi.org/10.1029/2009JA014502
10. C. Labanti, M. Marisaldi, et al. (2009), Design and construction of the Mini-Calorimeter of the AGILE satellite. Nucl. Instrum. and Meth. in Phys. Res. A, 598:470–479, https://doi.org/10.1016/j.nima.2008.09.021 

A complete list of my publications with metrics can be retrieved from the Astrophysics Data System (ADS). 

Below are my publications listed in the CRIStin database.

Active projects:

• 2024 – 2026 Principal Investigator, Conceptual design and prototyping of the Electrical Ground Support Equipment for THESEUS XGIS. Funding: European Space Agency. 
• 2023 – 2025 Principal Investigator, From lightning to the dawn of time: study of the timing structure of cosmic Gamma-Ray Bursts with the Atmosphere-Space Interactions Monitor. Funding: Peder Sather Center for Advanced Study. Collaboration project with the Astronomy Department at the University of Berkeley, USA. 
• 2021 – 2026 Principal Investigator, TGF Airborne Observatory (TAO): Understanding the link between lightning, terrestrial gamma-ray flashes and gamma-ray glows. Funding: Research Council of Norway. Partly funding the ALOFT flight campaign. 

Past projects as Principal Investigator:

• 2019 - 2022. Principal Investigator of the International Team 'Understanding the properties of the Terrestrial Gamma-ray Flash population' at the International Space Science Institute (ISSI), Bern, Switzerland.
• 2015 – 2016 International fellowship: Fulbright Research Scholar (6 months) at Duke University, Department of Electrical and Computing Engineering, NC, USA. 
• 2012 – 2014 Principal Investigator, ‘PICO: Picosecond Cherenkov Observatory’. Funder: National Institute for Astrophysics (INAF), Italy. R&D project for the exploitation of ultra-fast solid-state detectors for high-energy astrophysics in the TeV band.