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ISSI is a scientifically independent and neutral Space- and Earth Science institute that advances science by facilitating open multi-disciplinary discourse in a stimulating environment, reaching out towards new scientific horizons.
As Earth’s energy source and a variable star, the Sun has been credited over the past century with causing climate change that is a significant fraction of industrial-era warming… or so small as to be undetectable. Now, with more than forty years of space-based observations of solar irradiance and multiple geophysical quantities, and extensive advances in modelling solar irradiance and terrestrial variability, we can clarify with greater certainty the extent to which the Sun alters Earth’s environment, especially since 1850. This talk summarizes current observational evidence for the Sun’s role in global climate change and ozone-depletion recovery, and discusses the scientific (and societal) consequences of faulty detection and attribution.
Judith Lean is a senior scientist at the United States Naval Research Laboratory. She is a solar and climate scientist and her research focuses on the mechanisms and measurements of variations in the Sun’s radiative output at all wavelengths, and the effects of this variability on Earth, from the surface to space. Past Co-Investigator on UARS and SORCE missions. Testified to the US Congress on the role of solar output variations in climate change; chaired the National Research Council’s (NRC) Working Group on Solar Influences on Global Change. Served on multiple NSF, NOAA, NRC and NASA advisory committees. Author of more than 150 published papers and 300 presentations. Model reconstructions of solar irradiance variability have been used in multiple climate change simulations, including IPCC. American Geophysical Union Fellow (2002), US National Academy of Sciences member (2003), American Philosophical Society member (2013). Presidential Rank Award for Meritorious Senior Professional (2011).
The Hubble Space Telescope has been called the most productive scientific instrument in human history. Launched in 1990, the telescope has performed observations which have measured the age of the Universe, confirmed the existence of black holes, discovered the accelerating Universe, and amazed the general public. On Christmas day in 2021 the James Webb Space Telescope (JWST) was launched into space after decades of development. JWST was designed to extend the view of Hubble in regions of the cosmos Hubble can’t penetrate. JWST is exceeding the grand expectations of its ability to unravel the mysteries of the Universe. Join Astronaut/Astrophysicist John Grunsfeld as he takes us through the stories of Hubble and Webb.
Astronaut John M. Grunsfeld
John M. Grunsfeld is a scientist and former astronaut with extensive experience as a leader in human space exploration, space science missions, and national space policy. He has served as a NASA astronaut, the Associate Administrator for Science, and Chief Scientist at NASA Headquarters in Washington, D.C. Previously he served as the Deputy Director of the Space Telescope Science Institute in Baltimore, managing the science program for the Hubble Space Telescope and the forthcoming James Webb Space Telescope. Grunsfeld’s scientific research is in planetary science and the search for life beyond Earth. He has deep knowledge in Earth and Climate science and strategies to fight climate change.
The DART (NASA) and Hera (ESA) missions offer the first fully documented asteroid deflection test based on the kinetic impactor technique, allowing us to check and potentially validate our impact numerical models at the real scale of an asteroids. DART succesfully tackled the challenge to deflect the small moon, called Dimorphos, of the binary asteroid Didymos on September 26th, 2022, causing a decrease of the orbital period of Dimorphos around its primary. But many questions remain that will be answered by the Hera mission. Moreover, images sent by space missions to asteroids reveal that these objects are not simple rocks in space but very complex small geological world, whose response to external actions in their low gravity environment challenges our intuition. What did we learn from past missions, what are the challenges, the surprises and the remaining uncertainties? How will Hera measure the outcome of the DART impact and the properties of the asteroid? This presentation will address these questions that are not only relevant for planetary defense but also for the scientific understanding of those small worlds, which are the remnants of the bricks that formed our planets, and of the impact process, which plays a major role in all phase of our Solar System history.
Patrick Michel is Director of Research at CNRS (French Scientific Research National Center) and leads the Planetology team of the Lagrange laboratory at the Côte d’Azur Observatory (Nice, France). He is also Global Fellow (Professor with a foreign permanent affiliation) of the University of Tokyo (School of Engineering, Japan). With more than 220 publications in international peer-review journals, he develops numerical simulations of the impact process between asteroids, which reproduced for the first time real asteroid families, and of their surface and interior in their low-gravity environment.
“Do there exist many worlds, or is there but a single world? This is one of the most noble and exalted questions in the study of Nature.”
Albertus Magnus (circa 1200–1280)
Are there other worlds in the universe? Does life exist elsewhere in the cosmos? The technology of our time has made it possible to transform this dream of antiquity into a fascinating field of current astrophysics.
Three decades after the discovery of a first planet orbiting a star like our Sun, a few thousand planetary systems have been discovered. These first discoveries revealed to us the astonishing diversity of these systems, very different from our solar system: orbital periods of a few hours, planets with very high eccentricity, ocean planets, rocky or gas giant planets with sometimes retrograde orbits, etc.
After the euphoria of these first discoveries, the era of studying the atmospheres of exoplanets is now beginning. Fascinatingly, despite the enormous contrast between the high luminosity of the star and the very weak light that is emitted by the planets, the analysis of their atmospheres begins now. It will benefit from space telescopes and giant telescopes on the ground (up to diameters of 39 m).
Does life exist in other places in the cosmos? – Vertiginous question – The analysis of planetary atmospheres may reveal biosignatures, these spectral characteristics induced by the development of life. Advances in spectroscopy studies of exoplanets make us think that the search for extraterrestrial life is possible.
Thirty International Teams have been selected by the ISSI Science Committee for implementation from the proposals received in response to the 2023 call.
As one of ISSI’s and ISSI-BJ’s tools, International Teams of up to 15 scientists address specific self-defined problems in the Space and Earth Sciences, analyzing data and comparing these with models and theories. The teams work together in an efficient and flexible format with typically 2-3 one-week meetings over two years. The results of the studies are published in the peer-reviewed literature.
The next call for proposals will be issued in January 2024.
NASA interest in climate change goes back decades, and the now 50-year long record of remote sensing has provided clear evidence of ongoing change, as well as process-based information that inform the climate models that help us explain what is happening (and what will likely happen in the future). This talk reviews the highlights of NASA’s work in this area across multiple methods as well as some of the ongoing challenges.
Gavin A. Schmidt is the Director of the NASA Goddard Institute for Space Studies in New York and was the acting Senior Climate Adviser to the NASA Administrator in 2021. He currently works on the simulation of climate in the past, present, and possible futures and has over 150 peer-reviewed publications. He was the author with Joshua Wolfe of “Climate Change: Picturing the Science” in 2009, and in 2011 was the inaugural recipient of the American Geophysical Union (AGU) Climate Communication Prize. He is a fellow of the AGU and American Association for the Advancement of Science and his 2014 TED Talk on climate modeling has been viewed over a million times.
The Earth’s magnetosphere shields our planet from hazardous space weather effects caused by solar disturbances and energetic particles. However, the global structure of the magnetosphere is still extremely difficult to describe. Major challenges include the scarcity of data sets, as well as the breadth of physical processes that need to be taken into account. Our ISSI Team explores various approaches that help to mitigate these challenges. Recent publications from our ISSI Team provide new insights into how to extract information about global magnetospheric and ionospheric structures, and how to combine global data analysis and global modeling in meaningful ways. The new results suggest potentially transformative ways to work with global datasets, develop new global models, and improve the accuracy of the current global models.
A paper by Samsonov et al. (2022) uses global X-ray imaging of the Earth’s magnetopause as a novel method that will provide us with knowledge about the shape of the magnetopause. The authors use two numerical global MHD models (SWMF and LFM) to simulate the X-ray emissivity in the magnetosheath and cusps, which are sources of soft X-rays due to charge exchange between solar wind ions and exospheric neutrals. Methods developed to extract the information about magnetopause location from synthetic X-ray images will allow to use the data from the future soft X-ray imagers for monitoring of large areas of the magnetopause. This methodology will allow to validate/modify our current modeling tools and approaches and revolutionize the understanding of magnetospheric response to external driving conditions.
A paper by Holappa and Buzulukova (2022) combines 24 years of observations of energetic particle measurements by NOAA POES satellites with simulation results from a global model of the Earth’s magnetosphere to study the effect of the interplanetary magnetic field (IMF) By component on the ring current. The authors showed that there is an explicit By-dependence of the Dst index, which is a measure of the ring current intensity, and that this dependence can be accounted for by a modified solar wind coupling function that includes a correction factor depending on the dipole tilt and IMF By. This study provides a novel contribution to understanding the complex and seasonally varying effects of IMF By on the magnetospheric dynamics by means of combining global datasets and global models.
A recent study by Stephens et al. (2023) uses machine learning techniques for data-mining of 26 years of magnetometer data from multiple satellites to reconstruct the global structure and evolution of reconnection sites, called X-lines, as well as different types of magnetic nulls, called O-lines, in the magnetotail. The study compares the reconstructed location of X-lines and O-lines with observations from MMS mission and finds a good agreement in most cases. The results from the study have potential to revolutionize our understanding of reconnection process on a global level, suggesting that reconnection in the magnetotail is reproducible with historic data sets, and the global 3D structure of the magnetospheric reconnection is reflected in global activity indices, their trends, and the solar wind energy input.
2D histograms of electron density observed by COSMIC data on the test set versus those predicted by the IRI model (a), and the novel neural network NET model (b). (c) Cumulative distribution of ratios between the IRI model and the COSMIC data on the test set; (d) Cumulative distribution of ratios between the developed NET model and the COSMIC data on the test set. Credit: Smirnov et al., 2023, Nature Scientific Reports (CC BY 4.0)
A recent paper by Smirnov et al. (2023) presents a novel neural network model of electron density in the topside ionosphere. The model has been developed and tested using 19 years of GNSS radio occultation data. The model consists of four parameters that describe the shape, height, and gradient of the F2-peak. The model is tested against in situ measurements from several missions and shows excellent agreement with the observations, outperforming the state-of-the-art International Reference Ionosphere (IRI) model by up to an order of magnitude, especially at 100-200 km above the F2-layer peak. This study provides a paradigm shift in ionospheric research, by demonstrating that ionospheric densities can be reconstructed with very high fidelity with the neural network model. The new model could be valuable for a variety of applications, including space weather forecasting, satellite navigation, and communication systems.
Contact: Natalia Buzulukova
References:
Holappa, L., and N. Y. Buzulukova (2022) “Explicit IMF By-dependence of energetic protons and the ring current.” Geophysical Research Letters, 49 (8), https://doi.org/10.1029/2022GL098031
Samsonov, A., Sembay, S., Read, A., Carter, J. A., Branduardi-Raymont, G., Sibeck, D., & Escoubet, P. (2022). Finding magnetopause standoff distance using a Soft X-ray Imager: 2. Methods to analyze 2-D X-ray images. Journal of Geophysical Research: Space Physics, 127, e2022JA030850. https://doi.org/10.1029/2022JA030850
Smirnov, A., Shprits, Y., Prol, F. et al. A novel neural network model of Earth’s topside ionosphere. Sci Rep13, 1303 (2023). https://doi.org/10.1038/s41598-023-28034-z
Stephens, G. K., Sitnov, M. I., Weigel, R. S., Turner, D. L., Tsyganenko, N. A., Rogers, A. J., et al. (2023). Global structure of magnetotail reconnection revealed by mining space magnetometer data. Journal of Geophysical Research: Space Physics, 128, e2022JA031066. https://doi.org/10.1029/2022JA031066
Earth’s magnetic environment is filled with a symphony of sound that we cannot hear. All around our planet, ultralow-frequency waves compose a cacophonous operetta portraying the dramatic relationship between Earth and the Sun. Now, a new citizen science project called HARP – or Heliophysics Audified: Resonances in Plasmas–has turned those once-unheard waves into audible whistles, crunches, and whooshes. Early tests have already made surprising finds, and citizen scientists can join the journey of sonic space exploration to decipher the cosmic vibrations that help sing the song of the Sun and Earth.
When solar plasma strikes Earth, it causes the magnetic field lines and plasma around Earth to vibrate like the plucked strings of a harp, producing ultralow-frequency waves. In 2007, NASA launched five satellites to fly through Earth’s magnetic “harp” – its magnetosphere – as part of the THEMIS mission. Since then, THEMIS has been gathering a bounty of information about plasma waves across Earth’s magnetosphere.
The frequencies of the waves THEMIS measures are too low for our ears to hear, however. So the HARP team sped them up to convert them to audible sound. By using an interactive tool developed by the team, you can listen to these waves and pick out interesting features you hear in the sounds. Humans are often better at picking out interesting wave patterns by ear than by eye – and can even do better than computers at identifying complex patterns that emerge during extreme solar events.
To start exploring these sounds, visit the HARP website.
In the blockbuster science fiction movie “Interstellar” (Warning: spoiler alert!), a team of intrepid astronauts set out to explore a system of planets orbiting a supermassive black hole named Gargantua, searching for a world that may be conducive to hosting human life. With Kip Thorne as science advisor, the film legitimately boasts a relatively high level of scientific accuracy, yet is still restricted by Hollywood sensitivities and limitations. In this talk, we will discuss a number of additional effects that may be important in determining the (un)inhabitable environment of a planet orbiting close to a giant, accreting black hole like Gargantua. In doing so, we hope to reach a greater understanding of the fascinating physics governing accretion, relativity, astrobiology, dark matter, and yes, even gravitational waves.
Jeremy D. Schnittman joined the Astrophysics Science Division at NASA Goddard in 2010 following postdoctoral fellowships at the University of Maryland and Johns Hopkins University. His research interests include theoretical and computational modeling of black hole accretion flows, X-ray polarimetry, black hole binaries, gravitational wave sources, gravitational microlensing, dark matter annihilation, planetary dynamics, resonance dynamics, and exoplanet atmospheres. He has been described as a “general-purpose astrophysics theorist”, which he regards as quite a compliment.
Marco Velli is the Johannes Geiss Fellow 2022 and Professor of Space Physics at the Earth, Planetary and Space Sciences Department, University of California, Los Angeles, USA. A student of the University of Pisa and Scuola Normale Superiore, he has spent research periods at the University of St. Andrews, Scotland, the Observatoire de Paris, France, Università della Calabria, Italy, and the Smithsonian CfA, Cambridge, MA, as well as the Jet Propulsion Laboratory, California Institute of Technology, where he remains a Senior Scientist. In the following paragraphs he answers a few questions – asked by Christian Malacaria, ISSI Post Doc – about his scientific work. Christian Malacaria is an X-ray astronomer with expertise in observations and data analysis of compact objects. He is a member of several X-ray missions such as Fermi/GBM, NICER and IXPE.
Christian Malacaria: What is the main advantage of being a Johannes Geiss Fellow at the International Space Science Institute?
Marco Velli: As a UCLA professor, I have several different official tasks and duties in addition to research, such as administrative, managerial and teaching. All these are an essential part of each scientist’s work but can become so cumbersome that eventually one is left with less and less time for the creative research process, or even just for enjoying in depth scientific discussions with colleagues and friends. The Johannes Geiss Fellowship (JGF) provides time away from the day-to-day hassle, allowing one to rediscover and enjoy pure research.
Being a JGF at ISSI offers numerous advantages, creating a highly favorable research environment. ISSI is a tranquil yet stimulating place, frequently visited by exceptionally interesting guests and featuring a vibrant atmosphere. Here, diverse scientists, both young and senior, from various backgrounds continuously come and go, providing opportunities for diverse brainstorming, which fosters innovative research projects. The peaceful environment and minimal mundane duties of ISSI allow me to feel comfortable and remain focused, free from distractions. Furthermore, ISSI provides a convenient apartment within a short walk of the institute, unlike my usual residence in Los Angeles, where I endure a one-hour traffic jam to get anywhere. In essence, as a JGF, the hassles of everyday life have been removed, making life at ISSI significantly easier. Moreover, at ISSI, I have been able to join several science teams and workshops, and even participate in meetings without being a formal team member. This opportunity is not available anywhere else in the world of space physics. Although my six-month Fellowship is coming to an end soon, I would reapply for the JGF experience right now. This experience has rekindled my enthusiasm for research, in ways that are impossible to replicate elsewhere.
Christian Malacaria, ISSI Post Doc, and Marco Velli, Johannes Geiss Fellow 2022
Christian Malacaria: What are the most important open questions in Heliophysics and how are they going to be addressed?
Marco Velli: One of the most significant and fundamental problem is the existence of the heliosphere itself, closely linked with other essential questions such as: why does the Sun have a functioning dynamo and magnetic field? How is the solar corona heated and the solar wind generated? How are solar flares and coronal mass ejections triggered and solar energetic particles accelerated? Unfortunately, even with years of research, we still lack a comprehensive model that effectively addresses these questions.
The main obstacles to answering these questions can be divided into two categories: the first is related to observations, the second to time-scales: to start from the second point, our knowledge of the basic mechanisms behind the solar dynamo is limited by the Solar cycle periodicity: we must base our statistics onthe 11-year (22-year full) cycle, and though we have some observational proxies dating back centuries, routine mesaurements of the solar magnetic field from Earth is limited to about 10 cycles, while direct measurements of the solar wind and of the x-ray corona date to the space age (< 5 cycles), with the highest resolution measurements from SDO being only about a decade old.
In addition, understanding the dynamo requires precise measurements of the magnetic fields and photospheric flows all the way to the solar poles, while we are limited from the ecliptic plane to measurements around 60 degrees. Such observations would be key in understanding the solar magnetic field, and indeed the ongoing joint ESA-NASA mission Solar Orbiter will move out of the ecliptic plane within the next few years hopefully providing major new discoveries over the coming decade. Complementary to that, NASA’s Parker Solar Probe is probing the solar corona directly and will be moving to a perihelion inside 10 solar radii from center within the next two years. The direct measurement of the solar wind and its magnetic field in this acceleration region by PSP is already revolutionizing our understanding of the solar corona and promises, in conjunction with Orbiter, a complete paradigm change within the decade.
A predictive theory based on solid observations of the solar dynamo, solar coronal heating and solar wind acceleration is fundamental to understand the dynamics of magnetized plasmas well beyond Solar or Stellar physics, from the interstellar medium to galactic halos, pulsar wind nebulae and black hole magnetospheres, active galactic nuclei and the hot intra-cluster medium. Solar flares and coronal mass ejections are at the lower end of energetic bursty phenomena associated with magnetized plasmas throughout the universe that are associated with the generation and acceleration of cosmic rays and the X-ray and gamma-ray universe more generally.
To progress in our understanding of the Heliosphere, key future missions should include a global constellation of observatories comprehensive of in ecliptic and out of ecliptic (polar) observations, allowing for a 3D reconstruction of the Heliosphere in its complexity and variability. Such a mission is of fundamental interest also in the context of space weather and of providing the plasma context and advance warning for future human exploration of the solar system.
Christian Malacaria: Given the importance of the social melting pot promoted by ISSI, what do you think is the role of science (and scientists) in society?
Marco Velli: Science is experiencing an unprecedented pace of breakthroughs across multiple domains, and the approach to scientific research is also undergoing a significant transformation. Large collaborative teams are replacing the traditional romanticized notion of the lone scientist working at their table. However, the amount of time devoted to science and critical thinking has not improved, and science classes in schools remain limited. This is concerning, as it may lead to generations of scientists with exceptional technical skills, but a limited understanding of the big picture.
The problem of “compartmentalized knowledge” can hinder scientific progress and our understanding of physics in several ways, including the limitations of our science, or the boundaries of our understanding. To prevent this, we need to apply scientific thought and critical reasoning to different environments, including everyday life. This would enable us to greatly expand the way science is practiced, and foster a more continuous form of education as opposed to the current discrete model.
Science no longer requires all-knowing gurus, as it did in the past. As science evolves, the role of “universalists” is fading, and team-based work is becoming the key to achieving groundbreaking goals. Each scientist is now part of a larger chain, and their responsibility is not solely to the advancement of science but also to a necessary knowledge of the limitations of the results and methodologies. This becomes even more paramount with the emergence of machine learning and artificial intelligence methodologies where understanding how a certain result has been obtained can become as difficult as the original question probed.
This also affects human interactions, where we must work together towards a common objective and contribute actively with critical thinking, rather than passively expecting higher organizations to take care of collective challenges. As scientists, we have a responsibility to help standardize this behavior and incorporate it as an ethical requirement. Given the privilege we hold as highly educated people, it is our duty to lead by example and promote a culture of collaborative work and continuous learning.
The Johannes Geiss Fellowship (JGF) is established to attract to ISSI – for limited duration visits – international scientists of stature, who can make demonstrable contributions to the ISSI mission and increase ISSI’s stature by their presence and by doing so will honor Johannes Geiss for his founding of ISSI and his contributions to ISSI, and for his many contributions to a broad range of space science disciplines.
