ST
Solar-Terrestrial Sciences

Solar-Terrestrial Sciences

Cosmogenic Radionuclides – The quest of studying the solar activity of thousands of years

Cosmogenic Radionuclides – The quest of studying the solar activity of thousands of years

Thanks to the invention of the Neutron Monitor in 1948 and multiple spacecraft which monitor the cosmic ray environment since 1970’s we now have a constant record of the solar activity over almost 70 years. Information prior to this space era, however, are rare and take us back in time only to the late 1930s, when ionization chambers have been introduced. This of course allows us only a narrow view on the solar behaviour compared to the age of the Sun and our solar system and big scientific questions concerning, e.g., the current solar cycle can not be answered as easily. However, because galactic cosmic rays interact with the surrounding atmospheric constituents once they enter the atmosphere they are also able to induce the production of so-called cosmogenic radionuclides such as 10Be, 14C and 36Cl, with half-life times of up to 1.39 million years. Luckily, once mixed in the Stratosphere and Troposphere, these radionuclides get attached to aerosols and therewith transported to the surface. Here they are deposited in natural archives like ice sheets, tree rings or sediments, where the information of the solar activity is stored. Thus, cosmogenic radionuclides offer the unique possibility of obtaining a solar activity record over thousands of years. However, although cosmogenic radionuclide measurements can, thus, in principle be used to reconstruct solar activity back in time, in order to understand the underlying physical processes as detailed as possible the production of the cosmogenic radionuclides has to be studied numerically. As shown in Fig. 1, thereby a variety of complex physical processes has to be addressed, starting with the particle population of galactic cosmic rays in the local interstellar medium, their modulation within the heliosphere, their transport in the Earth’s magnetosphere as well as their interaction within the terrestrial atmosphere.

Prior to the end of 2012 the unmodulated galactic cosmic ray (GCR) flux, also known as the local interstellar spectrum (LIS), had not been measured in-situ. But with Voyager I crossing the outer heliosphere at around 122 AU for the first time measurements of the low energy LIS (below ~500 MeV) became available and the existing models on the production of cosmogenic radionuclides had to be revised.

Once GCR particles enter the heliosphere they encounter the heliospheric magnetic field (HMF) which is carried outwards by the solar wind. Thereby, the lower energy GCRs are modulated as they traverse the HMF. This transport can be described by the Parker transport equation, taking into account five important terms: the outward convection by the solar wind, gradient and curvature drifts in the global HMF, the diffusion through the irregular HMF, adiabatic energy changes due to the divergence of the expanding solar wind, as well as local sources (e.g., particles accelerated at the Sun). However, most often the much simpler analytical force-field approximation, which depends only on the solar modulation parameter Φ, is used in the literature. Furthermore, nowadays instruments like, e.g., PAMELA and AMS02 measure the high-energy GCR component above 10 GeV in the Earth’s vicinity, which is not influenced by the modulation due to the HMF. The energy spectrum of the energy range most important for the production of the cosmogenic radionuclides (0.4 – 8 GeV), however, is still unknown.

Figure 2: Upper panel: Annual variations computed with the IGRF model. Shown is the difference between the cutoff rigidities as they were present in 1900 and the ones of 2016. Lower panel: Comparison of the paleo-geomagnetic field reconstructions by different groups relative to present magnetic field strengths. Courtesy: K. Herbst

The HMF, however, is not the only magnetic filter that CRs encounter on their way to the Earth’s atmosphere. The Earth’s magnetic field also plays a major role when it comes to the modulation of the CR spectrum on top of the atmosphere. Although low- as well as high energy particles can enter the atmosphere at polar regions only high energy CRs can do so at equatorial regions. There is, however, not only a spatial but also temporal variation that has to be addressed. These changes can be of short term, e.g. due to a strong solar particle events, on the basis of annual variations (see upper panel of Fig. 2) but also centennial time scales (see lower panel of Fig. 2). Thus, such changes influence the primary particle spectrum on top of the atmosphere, and therewith the production of 10Be, 14C and 36Cl.

The main motor for the production of 10Be, 14C and 36Cl are galactic cosmic rays (GCRs) consisting of ∼87% protons, ∼12% alpha particles and ∼1% heavier particles (see e.g. Simpson, 2000). Once inside the Earth’s atmosphere CR induce the evolution secondary particle cascades of  muonic, electromagnetic as well as hadronic origin. In particular the high energy secondaries of the latter are able to further interact with the atmospheric Nitrogen, Oxygen and Argon atoms due to spallation reactions as well as thermal neutron capture producing the terrestrial 10Be, 14C and 36Cl isotopes. Thus, there is a clear anti-correlation to the solar activity. As a consequence, during high solar activity the production of cosmogenic radionuclides is low, and vice versa.

After stratospheric- and tropospheric mixing on time-scales in the order of around two (10Be) up to twelve years (14C) cosmogenic radionuclides are being attached to aerosols and finally deposited in natural archives like ice sheets, tree rings or sediments, where the information of the solar activity of thousands of years is stored. Existing radionuclide records thereby showed that GCRs most likely are not the only CRs contributing to the production of cosmogenic radionuclides. Recently, unexpected production rate increases around 774/5 AD and 993/4 AD in all three records were observed. This started a fruitful scientific debate about the causes of such strong increases. With a multi-radionuclide approach of highly resolved 10Be records combined with 36Cl ice core data, in 2015 different scientific groups independently could infer that enormous solar eruptions were the most likely causes behind the observations.

By combining numerical modelling and observations it is possible to reconstruct the solar activity (in form of the solar modulation parameter Φ) back in time. A reconstruction based on 10Be records by Muscheler et al. (2007) is shown in Fig. 3. Amongst others, thereby the reconstruction strongly depends on the LIS model the numerical simulations are based on.

Figure 3: Reconstruction of the solar modulation parameter from 10Be measurements based on Muscheler et al. (2007). Courtesy K. Herbst

Nevertheless, one feature can be seen in all records: the so-called Grand Solar Minima, in which the Sun showed unusually long solar minimum activity over tens of years. Shown here are the reconstructions between AD1000 and AD2005, where six of these minima have occured: Gleisberg (1880-1914), Dalton (1790-1820), Maunder (1645-1715), Spörer (1450-1550), Wolf (1280-1350) and Oort (1040-1080). This immediately implies that the low solar activity observed in the current solar activity cycle is not that uncommon, and that we are well within another small Grand Solar Minimum (referred to as Eddy Minimum).

Figure 4: Comparison of the 14C – based solar-modulation parameter with the revised sunspot (light blue) and group sunspot (blue) numbers. All records show an running 11-year average. The red curve shows the 4C (neutron monitor)-based results of the numerical production calculations. Courtesy K. Herbst

 

In order to test the results a comparison of the reconstructed solar modulation parameter values with the sunspot number, which is a direct measure of the solar activity, can be performed. As can be seen in Fig. 4, a reasonably good agreement can be found. Furthermore, because the solar modulation parameter mathematically can also be linked to the HMF it is also possible to reconstruct the heliospheric magnetic field strength back in time and compare actual observations with geomagnetic-, sunspot number- as well as 10Be-/14C- based reconstructions. As can be seen in Fig. 5 an impressive correlation between the different records has been found.

Figure 5: Composite plot of the reconstructed heliospheric magnetic field strength from 1390–2016 based on cosmogenic 10Be (McCracken and Beer 2015; 1391–1748), 14C (Muscheler et al. 2016; 1390–1748), the sunspot number (Owens et al. 2016a; 1749–1844), geomagnetic data (Owens et al. 2016a; 1845–1964), and from near-Earth observations in space (1965–2016). Courtesy K. Herbst

 

For more background information the reader is referred to the publications by: 

Beer, McCracken and von Steiger, Springer Business & Media (2012), https://doi.org/10.1007/978-3-642-14651-0

Muscheler et al. (2016), Solar Phys., https://doi.org/10.1007/s11207-016-0969-z

Cliver and Herbst (2018), Space Sci Rev, 214:56, https://doi.org/10.1007/s11214-018-0487-4

 

This post was writtend by Dr Konstantin Herbst

Dr Konstantin Herbst from the Christian-Albrechts-Universität zu Kiel, Germany

SunPy: a Python solar data analysis environment

SunPy: a Python solar data analysis environment

Introduction

For many years now we know that our star the Sun influences the Earth in many different ways, via the total solar irradiance, solar energetic particles and coronal mass ejections. Understanding the influence of the Sun on the Earth requires many different types of measurements. For example, NASA’s Solar Dynamics Observatory (SDO) spacecraft, produces over 1 terabyte of data per day (Pesnell et al., 2012), the bulk of it in the form of 4096 by 4096 pixel images in multiple bandpasses. The Parker Solar Probe (launched 12 August 2018) will fly closer to the Sun than any previous spacecraft, exploring the Sun’s corona, the solar wind and source and transport of space weather phenomena, by taking both in situ and remote measurements. Understanding the underlying physics requires sophisticated data analysis and modelling of multiple differing physical domains.

Managing and analyzing these heterogeneous data to answer evolving scientific needs and questions requires increasingly sophisticated software tools. These tools should be robust, easy to use and modify, have a transparent development history, and conform to modern software-engineering standards. The SunPy Project (SunPy Community et al., 2015) aims to provide a free and open source software package with these qualities for the analysis and visualisation of solar data. SunPy is built on Python, a free, general-purpose, powerful, and easy-to-learn programming  language. Python is widely used in many scientific fields, and has found applications in data analytics, machine learning and educational environments. SunPy brings solar physics in to the scientific Python ecosystem.

Organization and description of the code

Figure 1: SunPy is used to overlay two maps of data taken at the same time during the total solar eclipse of August 21, 2017: a ground-based photograph of the corona (black/white image), and an extreme ultraviolet image of the disk of the Sun (yellow image) taken by the SDO Atmospheric Imaging Assembly. Courtesy of S. Christe.

SunPy focuses on providing access to online repositories of solar physics data, and objects that make it easy to manipulate and display those data. SunPy is built using other open source Python projects, notably Astropy, numpy, SciPy, pandas and matplotlib. For example, many solar datasets are two-dimensional images, represented in SunPy by a Map object. Maps use SunPy’s coordinate transformation framework, an extension of Astropy’s powerful coordinates package, thereby enabling support for transforming between all Astropy and SunPy coordinate systems. SunPy was used to overlay ground based images of the solar corona taken during the total solar eclipse of August 21, 2017, and space based-images taken by SDO (Figure 1)

 

Figure 2: SunPy’s example gallery.

Figure 3: Simulated coronal loop emission generated using SunPy. Courtesy W. T. Barnes.

SunPy’s also provides the TimeSeries object for manipulating and displaying time-ordered scalar data.  Also, all public-facing SunPy functionality is unit-aware, meaning that physical units must be specified as required.  SunPy provides code snippets to get users started (Figure 2), and project members are active in teaching the community about SunPy.  SunPy is used by researchers working at NASA, European Space Agency (ESA), and the US National Solar Observatory Daniel K. Inouye Solar Telescope.  SunPy can also be used for modelling work: Figure 3 shows an example of using SunPy’s coordinate and mapping abilities to model the emission from an arcade of solar coronal loops.

 

Governance and development model

SunPy was born at the 2010 Solar Image Processing Workshop in Les Diablerets, Switzerland.  It is run by a small volunteer board of scientists that sets SunPy’s goals.  The Lead Developer (currently Dr. Stuart Mumford) is responsible for the implementation of SunPy’s goals. Contributions can be made by anyone. The project is managed at github.com/sunpy/sunpy, and unit testing, continuous integration, and community review of contributions are implemented to reduce bugs and maintain quality.  Students supported by the Google Summer of Code and the ESA Summer of Code in Space programs have made substantial contributions to SunPy.  The SunPy project is also a member of NumFOCUS, a US-based nonprofit organization that promotes sustainable high-level programming languages, open code development, and reproducible scientific research.

Future

SunPy gives users access to the ever widening scientific Python ecosystem. SunPy 1.0 is under development for release later on this year. This version will use Astropy’s representation of time, bringing improved precision and leap second support to SunPy.  The usability of SunPy’s data acquisition infrastructure will also be improved.  SunPy 1.0 will also drop support for the Python 2 series and require Python 3.6 or higher.  SunPy is also developing NDCube, a multi-dimensional, physically aware data object that can represent more complex multi-dimensional datasets, such as that from NASA’s Interface Region Imaging Spectrometer (IRIS) and other spectrometer instruments.  Finally, SunPy’s affiliated package program encourages the development of SunPy-based code that performs specific scientific tasks such as analyzing solar radio spectra.

References

SunPy Community, S.J. Mumford, S. Christe, et al. 2015, Computational Science and Discovery, 8, 014009.

D. Pesnell, B. J. Thompson, and P. C. Chamberlin. The solar dynamics observatory (SDO). Solar Physics, 275:3–15, Ja

Jack Ireland, lead support scientist at NASA/GSFC and Communications Officer for SunPy Project

nuary 2012.

 

This blogpost is written by Jack Ireland from the SunPy Community

Jaime de la Cruz Rodriguez – ERC success in the field of solar physics

Jaime de la Cruz Rodriguez – ERC success in the field of solar physics

Coronal Heating Problem is one of the Sun’s unsolved mysteries where the corona is heated to over a million degrees and scientists have not figured out where the energy is coming from. Dr Jaime de la Cruz Rodriguez is tackling this 70 year old puzzle by first understanding the layer of the Sun below the corona – the chromosphere. He is awarded the prestigious starting grant by the European Research Council for his project SUNMAG: Understanding magnetic-field regulated heating and explosive events in the solar chromosphere.

 

Congratulations on your ERC fellowship! Tell us about the man behind the grant?

Thanks! I am a solar physicist from Spain now established at Stockholm University. I moved to Sweden from the Canary Islands in 2006 as a PhD student, that was quite a life change! I chose solar physics as a PhD topic because our proximity to the Sun allows us to apply very advanced techniques that are usually not possible with more distant astrophysical objects. I got the chance to move to Sweden in a moment when they had the largest solar telescope in the world, and it was a very attractive option. At a more personal level, I wanted to leave from Tenerife for some time, and Sweden looked like an exotic adventure at the time. But it turned out to be a new life for me: there I met my wife and we have two kids. After my PhD studies I had postdoc positions at University of Oslo and Uppsala University, where I worked with brilliant colleagues. Since 2014 I have worked in Stockholm University and nowadays I supervise 3 PhD students and 4 postdocs (including those from the ERC project).

Who/what do you give biggest credit for your success with the ERC grant and why?

ERC grants are awarded to scientists that have a very good idea to attempt making progress in a research field. Finding that idea and motivating why it is unique is not always an easy task. In summer 2016 our Institute installed a new instrument (CHROMIS) at the Swedish 1-m Solar Telescope, which allows observing the upper layers of the solar chromosphere with unprecedented spatial resolution (~75 km on the surface of the Sun). Back then, I realized how much potential these new data had. I wrote the proposal around this new instrument and the development of new analysis tools that will allow us to carry out very exciting science in the chromosphere.

Can you briefly describe the SUNMAG project for which you are awarded the prestigious ERC grant in 2017?

The heating of the solar chromosphere remains one of the foremost question in solar and stellar physics: how is energy transported and deposited in this thin layer of the Sun located about the visible surface (the photosphere) and the million-degree corona?
The main obstacle to study this elusive layer of the Sun is that it requires very complex physics to model the observed intensities (spectral lines): it is very challenging to convert the intensities to the underlying physical state of the plasma.

The SUNMAG project will study how the chromosphere is heated in regions with strong concentrations of magnetic field. To do so I have developed a technique that allows to reconstruct a 3D model from our observations. These models contain the stratification of gas temperature, density, velocities and the magnetic field vector with height. I will use these models to study and characterize how the chromosphere is heated in active regions and explosive events like flares. In this region, the magnetic field is expected to play a fundamental role in the structuring and energy transport of the chromosphere.

The reason why this project is finally possible is twofold:
• A new analysis tool that allows reconstructing models from spectroscopic observations (described above) of the chromosphere. While these techniques already existed, for the first time our code allows for the inclusion of spectral lines that are sensitive to the middle and upper chromosphere.
• New instrumentation that allows to spatially resolve the scales at which energy is expected to be released in the solar chromosphere. The CHROMIS instrument at the Swedish 1-m Solar Telescope basically doubles the spatial resolution of previous instrumentation, while also providing rich spectral information.
I believe that with this project I can help to take steps towards solving the chromospheric heating problem.
Just to provide some context, the image illustrates a co-temporal observation of the solar photosphere and chromosphere (top panels), acquired at the Swedish 1-m Solar Telescope. The photosphere (left panel) is dominated by convective cells (granules) and strong concentrations of magnetic field (sunspots). In the chromosphere this convective panel is lost and we start to observe elongated structures that are usually aligned with the magnetic field. We know that in magnetically active regions the magnetic field intensity (generally) decreases as we move upwards. We also know that the magnetic field is highly confined in the photosphere whereas it expands forming magnetic canopies in the chromosphere. These differences are illustrated in the lower panels of the image, where the left panel shows many sharp red structures in comparison with the right panel. In the right panel however, we can discern a green halo in the central part of the image that traces the presence of these magnetic canopies. In the image the red color indicates regions where the magnetic field is aligned with the line of sight of the observer (vertical fields), whereas the green color indicates regions where the magnetic field is contained in the plane of the surface (horizontal fields).

What aspects of the project are you most excited about and what aspects are least exciting?

I am most excited about flare studies. It is a real challenge to understand the observations, but I think we can help a lot as our techniques have not been applied in many studies to this kind of data. This part also has an interdisciplinary component. For example, our code provides estimates of the magnetic field in the chromosphere and that information could be used in other fields like space weather. I am less excited about some programing parts of the project that I will need to undertake. That part is usually less regarding and very time consuming.

In 2017 Stockholm University has bagged 7 ERC grants, including yourself. What does the University do to achieve such success?

Stockholm University is an excellent place to work and perhaps having successful applicants starts by having competitive research groups where those young researchers can develop their ideas and settle with their own groups. Research is very competitive at the moment, but competition used in a constructive way can be a very powerful tool. More pragmatically, I got excellent support during the application process and for the interview in Brussels.

What was the most difficult part of the application process and how did you overcome it?

I personally found the interview part is particularly difficult. I never have had issues with managing my nerves, but that day I didn’t have a steady hand when I entered the room. The panel did a very good job digging out the weaknesses of the project. I managed to overcome this difficult part by not trying to fiercely defend every criticism that I got during the interview. There are always limitations and it is better to be aware of them and to have them somewhat under control.

Apart from your accomplished research, what other duties do you perform? Do you think any of these duties gave you an edge over other applicants during the ERC decision?

Teaching and supervision. The latter is an important asset, especially if the project involves PhD students. I suspect that having zero supervision experience can be problematic in that case.

What are your other interests? How have they been affected since your award?

Professionally I am working in my prime scientific interest, which is great! The award has affected other aspects of my life, including my employment at Stockholm University which is now permanent. Outside science, sports have always been an important part of my life, but that part remains unaffected.

Lots of tips from Jaime for aspiring ERC applicants. Wishing him the very best for this project.

The average magnetic field and polar current system (AMPS) model

The average magnetic field and polar current system (AMPS) model

Karl Magnus Laundal. Credit: BCSS

In this month’s post, Karl Magnus Laundal explains a newly developed empirical model for the full high latitude current system of the Earth’s ionosphere, AMPS (Average Magnetic field and Polar Current System). The model is available and documented in python code, published under the acronym pyAMPS. The community is invited to download and explore the electric currents and magentic field disturbances described by the model.

 

 

The average magnetic field and polar current system (AMPS) model

At about 10 times airline cruising altitude, at the boundary to space, the atmosphere is so thin that charged particles, electrons and ions, are not immediately neutralized in collisions. This inner edge of space, which extends from about 100 to 1000 km altitude, is called the ionosphere. In contrast to the neutral atmosphere, the charged particles feel the forces of electromagnetism. These forces depend strongly on the interaction between the solar wind and the Earth’s magnetic field, which happens much further out, at about 10 Earth radii (roughly twice as distant as geostationary satellites, but well inside lunar orbit). The result of this interaction is communicated to the upper atmosphere along magnetic field lines, and as a result, a 3-dimensional current system is generated in the ionosphere. This current system can change very rapidly, partly because of changes in the solar wind and in the interplanetary magnetic field.

Field aligned currents (red/blue) and divergence free horizontal currents (contours) from AMPS, during the course of a day. Credit: K.M. Laundal

The AMPS model describes the average ionospheric magnetic field and current system for a given solar wind speed, interplanetary magnetic field vector, orientation of the Earth’s magnetic dipole axis, and the value of a solar flux index (F10.7). The model is empirical, which means that it is derived from measurements. We use measurements of the magnetic field, from the CHAMP and Swarm satellites, in low Earth orbit. For each measurement, model estimates of Earth’s own magnetic field, and the magnetic field associated with large-scale magnetospheric currents, have been subtracted. The remaining magnetic field is assumed to be related to ionospheric currents. Millions of measured magnetic field vectors are used to fit several thousand unknown parameters in an intricate mathematical function that describes the ionospheric magnetic field at any point in time and space. Electric currents are calculated from the magnetic field.

Model values of AMPS magnetic fields and currents can be calculated with the Python library pyAMPS, which is located here: https://github.com/klaundal/pyAMPS (documentation here: http://pyamps.readthedocs.io/).

This is not the first empirical model of ionospheric currents and magnetic fields, but there are a couple of important characteristics that sets the AMPS model apart from others: First, we have corrected for variations in Earth’s own magnetic field, which strongly distorts the ionospheric currents. This allows us to make precise comparisons between hemispheres. We have not imposed any symmetries between hemispheres; for example seasonal variations are not necessarily the same in the north and south in the AMPS model. Finally, this is the first empirical model to describe the full ionospheric current system, and not only the field-aligned part or the parts which circulates horizontally. This allows us to calculate full horizontal ionospheric current vectors without any assumptions about conductivity.

These unique features are made possible by the dataset provided by the CHAMP and Swarm missions, of very accurate magnetic field measurements from low orbit. The CHAMP satellite reentered Earth’s atmosphere in 2010, after 10 years of operation. In 2013, ESA’s Swarm satellites were launched, three satellites that carry even more precise magnetometers than CHAMP. So far, two of the Swarm satellites have flown side-by-side, near 450 km altitude, while the third satellite is a little higher. Swarm is expected to stay in space for many years, and we plan to release updated versions of the AMPS model as the data set grows. The production and publication of the AMPS model is supported by ESA through Swarm DISC.

A paper describing the model has been published in Journal of Geophysical Research – Space Physics: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JA025387 (open access)

For more background on the technique, see an earlier paper in a special Swarm issue of Earth, Planets, and Space:
https://earth-planets-space.springeropen.com/articles/10.1186/s40623-016-0518-x (open access)

Prof. Ilya Usoskin – A discussion with an inquiry mind

Prof. Ilya Usoskin – A discussion with an inquiry mind

In the May issue of the Life of a Scientist we have the pleasure to talk to Prof. Ilya Usoskin from the Univeristy of Oulu, Finland. Among numerous things, he is the head of the Oulu Cosmic Ray station and receipent of this year’s Julius Bartels EGU Medal; a decision that was based:  “on his contributions to the understanding of the heliosphere, long-term changes in the solar activity and solar-terrestrial relations”.

Prof. Usoskin, can you please introduce yourself ?

I am a Russian-born and -educated scientist living and working in a quiet and charming city of Oulu in Northern Finland. In my research I combine both experiment and theory.

Prof. Ilya Usoskin (Credit: Ilya Usoskin)

As an experimentalist, I am the head of a cosmic ray station and operate a ground-based neutron monitor of Oulu, which is recognized as one of the most stable long-running neutron monitors in the world, a muon telescope, and, since 2015, the world’s most sensitive to low-energy cosmic rays neutron monitor on the Antarctic plateau, thanks to hospitality of the Franko-Italian Antarctic station Concordia. As a theoretician, I am focused on cosmic-ray induced effects in the Earth’s atmosphere, including the firstly developed full numerical model of cosmic-ray induced atmospheric ionization. Of course, as rooted in both experiment and theory, I work actively on data analysis and interpretation, with emphasis upon long-term solar and cosmic-ray variability.

You are a recognized expert in cosmic rays, solar-terrestrial relations, neutron monitors and space weather. What got you motivated, in the beginning of your carrier?

If you expect a nice story of a strongly motivated fellow who was developing according to a well elaborated plan, this is not my case. Earlier part of my career was more like a random walk. No focused motivation or conscious choices. Eventually I migrated to the field where there was a large gap, viz. sensitivity of a neutron monitor to solar energetic particles, and I explored this deeper. Then a new gap in the knowledge was found, and another one…

Do you have any analogies to help us understand what you do ?

There is a remote analogy. Imagine, you permanently reside in your homeland and grow crops. Of course, you want to know about the weather – can you thresh the grain today or better wait until tomorrow? You may know some weather lores, e.g., that the red sunset implies a windy day tomorrow, or from the shape and color of clouds you can predict that rain will start soon, and you start stacking the hay… That’s what Space weather does. We study Space climate. Keeping the same analogy, we try to understand the overall long-scale processes driving the everyday weather. We try to estimate the probability of a cold or warm winter to occur this year or a decade ahead. Of course, the exact weather for each particular day next summer cannot be predicted, but a probability of a cold and wet summer to occur can be evaluated.

At the General Assembly in 2018 you have been awarded the prestigious Julius Bartels Medal. Can you please briefly share with us your discoveries that have lead up to this point?

I am not very sure what were the discoveries which lead to the point. In fact, I haven’t made any discovery, but some results are interesting, at least for me. In particular, we were the first who applied a full Monte-Carlo simulation of the nucleonic-muon-electromagnetic cascade, initiated by cosmic ray in the Earth’s atmosphere, to assess the cosmic-ray related effects. Applying this method to cosmogenic isotopes 14C and 10Be, we were able to perform the first quantitative physics-based reconstruction of solar activity on the multi-millennial timescale. We have shown that solar activity was unusually high during the second half of the 20th century, corresponding to a special case of a Grand maximum, but I would not call it a “discovery”. Generally, IMHO, a systematic study leading to a breakthrough in the long-term solar variability was appreciated rather than “discoveries”.

You are considered as a co-founder of Space Climate, can you please explain what that means in greater detail?

Space Climate implies long-term systematic changes in the near-Earth environment. It is more complex than just a temporal average of Space Weather, because in the latter you cannot see slow trend, tendencies. I would rather say that Space Weather is a snap-shot, instant projections of Space Climate. As a long term we mean everything longer than interannual variability (phases of the 11-year solar cycle) and up to millennia.

I would not agree to be regarded as a founder of the Space Climate discipline. The real father of it is Kalevi Mursula, with whom we discussed 15 years ago that the newly emerging concept of Space Weather is missing an important component, viz. long-term variability. To fill the gap, we organized the first International Symposium on Space Climate in Oulu in 2004, which has become the main Space Climate forum. In February 2019, we will conduct, in Canada, the seventh Symposium of the series, which collects ~150 scientists from all over World. We also regularly convene the related sections at COSPAR, EGU and AGU Assemblies.  As an oversimplified analogy, you can study details of summer weather, but then you will be totally surprised during the winter, if you are not aware of different seasons. Most of Space-era data were based during the period of the Modern grand maximum of solar activity, in the second half of 20th century. You can often hear that the Sun is abnormally quiet nowadays. But this is not correct – the Sun is now at its normal moderate level of activity, while it was abnormally active during the previous decades.

Does the future of your research field lie in interdisciplinary synergies and how important is the unrestricted access to data, today?

Exactly ! The future is in inter- and mutli-disciplinary research conducted by teams of experts. This implies the use of different types of data, and free access to level 1-3 data with full metadata is crucial for that. Data of level 0 can be, of course, kept for internal use, but shall be provided to anyone upon request. Unfortunately, the experience shows that errors may occur at any step even with best datasets, and reproducibility of the result is one of the basic principles of doing sciences.

Based on your experience, what scientific questions in your field could be solved in the near-future and why?

We are now approaching the stage when solar variability can be “absolutelyreconstructed from cosmogenic isotopes on the multi-millennial time scale, including individual solar cycles. Previously, only averaged evolution was possible to assess with somewhat “shaky” calibrations. Another very promising idea is to study extreme solar events. Just 6 years ago we could not imagine that a full analysis of strong solar events in the past, before 19th century, is possible. Now we know three such events, and there will be found more, I am sure.

Overall, we will have a quantitative (with higher quality that the sunspot number record on 400 years) record of solar activity over millennia.

What current idea you consider as the most potential ?

Personally, I am most interested now in the extreme solar events. We are close to defining the limit of our Sun in producing such events, and to assessing the probability of their occurrence, which is crucially important for both science, by providing new unique data on solar activity, and space technology and exploration. You would definitely want to know what “worst-case scenario” you may expect from the Sun and what is the probability of this scenario to be played by the Sun during, e.g., a manned mission to Mars. There is a focused research community attacking this problem from different points of view (precise measurements, realistic modelling, sophisticated data analysis), and we will meet in October this year for a dedicated workshop in Japan (supported by Nagoya University)

What would you like to convey to young researchers who want to work in your field?

My message is very simple: Do what you like in the best possible way ! Try to read state-of-the-art works by best scientists and to say “Hey, it’s good, but I can do it better !” – and then just try to do it better !

Report from the 2018 EGU General Assembly

Report from the 2018 EGU General Assembly

Last week the 2018 General Assembly were held in Vienna. Gathering 15 075 scientists from 106 countries, this is the most important EGU event throughout the year. Summarizing what happened during the week is an impossible task, as a meeting like this is way more than the 666 individual sessions convened and the 11 128 posters presented during the week. However, in this post I will point to some of the ST Division specific highlights.

This year, spring came to Vienna together with EGU. Many of us therefore used this excellent opportunity to stay outside in the sun to relax or explore the beautiful medieval city, in between the busy meeting schedule. However, the main activities happened inside the Austria Center Vienna. 

During the Solar-Terrestrial Division meeting, Theresa Rexer was announced as the new Early Career Scientist (ECS) representative in the division, taking over from Jone Peter Reistad. She will continue the ongoing efforts to make the General Assembly even more relevant for students and researchers in the early stages of their career. During the General Assembly, the Solar-Terrestrial ECS team held the session “Meet the Experts: The Future of Solar Terrestrial Research”, for the fourth year in a row. The session was very well attended (78 participants) and the invited speakers did an excellent job in reviewing important challenges and topics relevant for ECS to embark upon in the near future, covering topics from the Sun to the magnetosphere, ionosphere, and its coupling with the atmosphere.

This year we had three medal awardees in the ST division. Ilya Usoskin received on the Monday the Julius Bartels medal for his “key contributions to long-term changes of cosmic rays and solar activity, qualifying him as a founder of the space climate discipline”. The next day Eckart Marsch received the Hannes Alfvén medal for “fundamental contributions to our understanding of the kinetic processes and plasma turbulence in the heliosphere, as well as for work that helped HELIOS become a successful mission and initiated the Solar Orbiter.” Finally, Natasha L. S. Jeffrey received the Division Outstanding Early Career Scientist Award for “her outstanding achievements in improving the standard model of fast electrons produced in solar flares, thereby eliminating the long-standing low-energy cut-off uncertainty.” (citations are from https://www.egu.eu/awards-medals/).

In the Solar-Terrestrial Division, a total number of 34 session were held, making up a varied program within most of the disciplines of our division due to all the contributions and efforts from the community. I can only say that I look very much forward to the meeting in Vienna next year!

Cosmic rays – messengers from space

Cosmic rays – messengers from space

Cosmic rays (CRs), are not actually rays, but highly energetic charged particles of extraterrestrial origin. The life cycle of a cosmic ray particle starts with its birth at some point in the Universe, its travel at nearly the speed of light and finally with its death ( e.g. at a detector). These highly energetic particles strike our planet from all directions and thus provide a constant background. In practice, this means that thousands of cosmic ray particles pass through our bodies every minute, but the resulting radiation imprint is relatively low if we compare this to the natural background radiation.

Sources of CRs, encompass the Sun, our Galaxy and beyond. As a result, these charged particles span almost ~35 orders of magnitude in flux and ~14 orders of magnitude in energy. This, means that we need many different experimental devices (e.g. spacecraft data, neutron monitors, muon telescopes, AMS02, PAMELA, TRACER, IceTop, Pierre Auger Observatory and many more) to capture the entire spectrum of CRs and at the same time this offers many opportunities to evolve our experimental/detection set ups and our understanding.  We measure the energy of CRs in eV (electron-Volt: it corresponds to the energy gained when an electron is accelerated through a potential difference of 1 volt). Based on the energy of CRs, we can identify the origin and map different parts in the spectrum. For example, above a few GeV/nucleon, the energy spectrum of CRs follows a power law proportional to E−2.7. At 1015 eV there is a break in the spectrum, which is typically referred to as the “knee”, below this energy CRs are of Galactic origin. From the “knee” up to 1018 eV the power law falls as E−3.1. A second break in the spectrum occurs at 1018 eV, usually called the “ankle”, where the spectrum flattens. At this energy it is possible that the particles can be of extragalactic origin. The CR spectrum continues up to 1020 eV, which is the current high-energy limit for CR observations.

The spectrum of CRs, denoting the different components and sources (Credit: A. Papaioannou, adopted from the CR spectrum by S. Swordy).

Low energy (up to ~1015eV) Galactic CRs (GCRs) are most likely accelerated in supernovae (SN) shock waves which occur approximately once every 50 years in our Galaxy. GCRs are the only matter originating from outside our solar system that can be studied directly. Thereby, their composition and energy spectra can be used to determine their sources, acceleration mechanisms and transport processes in the Galaxy. However, since CRs are charged particles those are deflected by magnetic fields. This, in turn, obscures the identification of their actual source, since their travel paths have been randomized.

At the same time the Sun is an additional sporadic source of energetic particles, often termed as solar CRs (SCRs) and/or Solar Energetic Particles (SEPs).  These particles are accelerated by shock waves driven by coronal mass ejections (CMEs) traveling through the corona, and by the magnetic energy that is released in solar flares. When a CME occurs 100 million tons of hot coronal gas is suddenly ejected into space at speeds of 1.6 million km per hour. SFs are observed in white light, UV, soft and hard x-rays, gamma-rays, neutrons and radio waves and hence cover the entire electromagnetic spectrum. When CRs penetrate into our solar system, those are affected by the interplanetary magnetic field (IMF), which is  embedded in the solar wind blowing from the Sun. Therefore CRs have difficulty reaching the inner solar system and Earth. Solar activity (and the rate of CMEs and SFs) varies over the 11 year solar cycle, leading to a variation in the intensity of CRs at Earth, in anti-correlation with the solar activity (as represented by the sunspot number). Furthermore, the interplanetary counterparts of propagating CMEs reduce the GCRs flux, leading to a decrease known as the Forbush decrease.

The heliospheric enviroment. Inserts include, an artistic representation of the Sun-Earth relations (Credit: NASA), a solar flare (SoHO/EIT), a coronal mass ejection (SoHO/LASCO), the recent Solar Energetic Particle (SEP) event from 10 September 2017 and the corresponding recordings from spacecraft (GOES) and neutron monitors on the ground (Ground Level Enhancement – GLE; NMDB) (Credit: A. Papaioannou)

If CRs are energetic enough and reach the Earth’s atmosphere, undergo collisions with its atoms and produce a cascade of secondary CR particles that shower down through the atmosphere to the Earth’s surface. These secondary CRs include pions, electrons and positrons. The number of particles that reach the Earth’s surface is related to the energy of the primary CRs that made it to the upper atmosphere. The deeper the particles penetrate into the atmosphere, the more energy they lose.  A SF and/or a CME may result to an intense flux of SCRs, which gives ground to an SEP and when recorded on the Earth’s surface, to a Ground Level Enhancement (GLE).

GCRs, being messengers from space, hold a key for the greater understanding of our universe, since the most exciting frontiers of astrophysics involve physical processes and environments that are not reproducible in the laboratory. In addition, CRs carry information from their interaction with the magnetic irregularities they encounter en route to the Earth and help us track our heliospheric environment. They also quantify the radiation levels encountered by air crews on flight altitudes and by astronauts in space.  

A synthesis of different figures showing the RAD on MSL on the surface of Mars; RAD’s field-of-view and the corresponding parts of the detector, as well as , the historical photo of Victor Hess in a ballon en route to the discovery of cosmic rays (Credit: A. Papaioannou, using figures from this presentation)

In August 2012, 100 years since the discovery of CRs from Victor Hess, the Radiation Assessment Detector (RAD) onboard the Mars Science Laboratory (MSL) measures for the first time CRs on the surface of another planet.

A thrilling new era has already began !

 

Social media response to geomagnetic activity

Social media response to geomagnetic activity

Social media platforms offer every person with internet access the possibility to share content of various kind. The recent increase in social media use globally give birth to new tools and insights, from a different perspective. The size of, and the global nature of the user driven social media, makes one expect it to include information also about geomagnetic activity related to posts of visual observations of the aurora by the users. Inspired by the ongoing Aurorasaurus initiative, an outreach project with a High School class in Norway was undertaken, where the students were given the task to see if they could find any connection between the number of social media reports of aurora (using Twitter), and the observed level of geomagnetic activity (using the AL index). Their results showed a highly significant correlation, especially during the months of high geomagnetic activity, as seen in the above plot.

We here include a short project report from one of the groups to share details on how the investigation was done. The text has been prepared by Simen Sande Bergaas, Lea Sommersten Brandstadmoen, Trym Svardal Larsen, and Ingri Østensen from Langhaugen High School, Norway, together with two of their teachers.

The students from Langhaugen High School participating in the project. Credit: Silje Rognsvåg Reistad

Introduction

We wanted to find out whether social media could be a valid source for finding out how much northern light there had been, and when it appeared. We used Twitter as our social media, and searched on one specific date, so we could see how much northern light there had been each day. We wanted to see if there were any similarities between a geomagnetic activity index (AL) and the number of hits we got on Twitter.

Method

  • Each group looked at one month between September 2016 and April 2017
  • We counted the hits on Twitter for #northernlights and/or #auroraborealis each day of our month
  • We plotted these results together with the daily average geomagnetic index (AL) using Excel.

Results

As we can see from the top figure, we got a good match between the daily Twitter count and the AL index. We got similar results for most of the eight months. The only month that we did not see any correlation was December, in which had very low Twitter counts.


How many of the Tweets were relevant?

One of the groups wanted to do something more with the project, and decided to count how many of the posts we found were relevant, and actually showed northern lights that had occurred that day. We chose one of the days, and then we counted. The result is shown in the figure below. The day we counted, there were 96 posts. Out of these 96 posts, 22 did not contain relevant information to our project. That equals 23% non-relevant posts, and 77% relevant posts.

Breakdown of all Twitter posts on March 11, 2017. Most of the posts (77%) were found to be related to auroral activity.

 

Conclusions

What we saw from these statistics was that there are similarities between the measurements and the Twitter posts. We can say that social media can be a somewhat valid source for describing the geomagnetic activity level, but not a waterproof one. Looking at the other months, it looks like the correlation improves during active times, while December, which was a quiet month, had very poor correlation. We also see that on March 11, very few of the posts were non-relevant, which strengthens the credibility of social media as a source. 

 

The students presented their work on posters to the Birkeland Centre for Space Sciance at the University of Bergen, Norway.

How do we study the magnetosphere?

How do we study the magnetosphere?

Our closest star, the Sun, is constantly emitting hot gas in all directions as its upper atmosphere, the corona, expands. This is known as the Solar Wind, also carrying with it an embedded magnetic field, the Interplanetary Magnetic Field (IMF).  The IMF originates  at the Sun and forms an enormous spiral throughout the solar system as the solar wind escapes radially, while the magnetic field-lines are anchored to the rotating Sun. This is the large-scale environment, or the laboratory, for a magnetospheric physicist. The core of magnetospheric physics is to increase our understanding of the complex interactions occurring when a magnetized planet is exposed to this solar wind and IMF environment. This blog-post will briefly mention some of the ways we study this interaction, and what kind of questions we try to answer about the solar wind – magnetosphere system.

First of all, what is a magnetosphere? A magnetosphere is the region around a magnetized planet where the magnetic field is the one related to the planet itself. The other magnetic domain is the one only connected to the Sun or solar wind, referred to as the IMF in this context. As for the Earth, the boundary between the Earth’s magnetic field and the IMF field-lines is rather sharp. On the dayside, this boundary, known as the magnetopause, usually sits at about ~10 Earth radii toward the Sun at the subsolar location, and wrap around to form a blunt surface that define the magnetosphere, as seen in the image above, forming a long tail in the anti-sunward direction.

When the solar wind and the IMF interact with the magnetosphere a variety of processes take place. Most interesting – when it comes to energy and momentum transfer into the magnetosphere system –  is the magnetic interactions, initially taking place at the dayside magnetopause. Through a process known as magnetic reconnection, field-lines initially connected only to the planet can merge with the incoming IMF to form field-lines magnetically coupled both to the planet and to the Sun/solar wind. This allows these newly opened field-lines to be pulled tailward by the solar wind, while still being anchored to the Earth. This is how most of the solar wind energy enter the magnetosphere system, which could reach values of Terra Watts during geomagnetic storms. A consequence of the dayside reconnection process is that the reservoir of field-lines connected only to Earth is continually reduced. The magnetosphere’s way of solving this problem is through creating new field-lines that have both their footprints anchored to the planet, again through the process of magnetic reconnection. This happens deep within the magnetotail, and causes momentum and energy to be transported toward the planet, responsible for a variety of phenomenon that we can see and measure on the ground at Earth. Most notable are the aurora borealis and -australis visible in bands around the magnetic poles, and associated magnetic disturbances. Interestingly, the entry of the solar wind plasma (particles) itself into the magnetosphere is not very important in describing the aurora. The accelerated particles causing the aurora largely originate from within the system although their energy come from the solar wind.

Nighside aurora seen from the EISCAT Svalbard radar site. Credit: Jone Peter Reistad.

When studying the magnetosphere, a large variety of instruments are being used. One can distinguish between two types of measurements that complement each other, to a large degree. To measure the influence from a large region of the mangetosphere simultaneously, remote sensing techniques are applied. One example of such is observations of the aurora, where the light originate from the high latitude ionosphere at typically 100-200 km. Since the magnetic field at high latitudes map out to very large regions of the magnetosphere, the aurora can be interpreted, to some extent , as a screen illuminating the more distant magnetospheric processes. Therefore, by studying the high-latitude electrodynamics close to the ground, one can infer properties of the much larger magnetosphere. The other type of measurements is in-situ observations of physical quantities such as electric and magnetic fields/waves and charged or neutral particles. This is usually obtained from satellites orbiting within the magnetosphere. One major challenge when interpreting such data in terms of the big system is that they only provide point measurements in a huge system. Also, temporal and spatial variations are in general mixed, as stationary is difficult to obtain/determine. Hence, remote-sensing and in-situ measurements addresses different spatial scales and often different processes in the magnetosphere system, and act  complementary to each other in order to obtain increased knowledge of how the system works. Recent missions that has greatly contributed to increase the understanding of the solar wind – magnetosphere – ionosphere interactions include Cluster, THEMIS, Swarm, Van-Allen Probes, and MMS.

Although we have learned a lot, especially through the space age, of how the solar wind and IMF environment affect the mangetosphere, many questions still remain. One example is the very nature of the reconnection process, which is a fundamental plasma process allowing efficient energy transfer into the system. A dedicated mission, the Mangetospheric Multiscale Mission was recently launched to investigate its details by probing the reconnection region at finer spatial scales than ever before by 4 closely separated spacecrafts. At present, most models describing the large-scale distributions of the important parameters in our system are indeed very static. We know that the reality is highly dynamic and structured, and it remains as an outstanding challenge to further enhance our understanding of the complexities in our system to be able to more accurately predict the outcome of the solar wind – magnetosphere – ionosphere interactions.

Dr. Helen Mason – Solar space missions: a life with the Sun

Dr. Helen Mason – Solar space missions: a life with the Sun

In the December issue of Life of a Scientist we have an interview of Dr. Helen Mason. She was working at the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge, UK until recently when she retired. Her research interests include UV and X-Ray spectrum of the Sun. She has also devoted a lot of time in promoting science and working with schools from all over the world. Retirement for her means “more time for outreach and work with schools”. She has been awarded the OBE (Order of the British Empire) for her public service.

Dr. Helen Mason, OBE

What got you interested in solar physics?

I had an interest in astronomy from an early age. As a small child, I can remember looking up at the night sky with wonder. I studied physics and astronomy at university (Queen Mary College London), and did a topic on the solar wind for my dissertation. I found it fascinating. I was lucky enough to get a PhD place with Prof Mike Seaton at University College London, UCL, to study atomic physics and solar eclipse spectra.

What was your personal drive behind creating the CHIANTI atomic database which is widely used by the stellar and solar physics communities?
CHIANTI is an atomic database setup to calculate spectra from astrophysical plasmas

My expertise is in spectroscopy and atomic physics. I have calculated a lot of atomic data for the coronal visible, UV and X-ray lines. I realized that it was not easy for the solar community to access and use all these data. Ken Dere, from the USA, Brunella Monsignori-Fossi, from Italy, and I met for lunch at a solar physics conference in Italy, and we decided to make atomic data freely accessible online with a user-friendly interface. We decided to call this package CHIANTI, because we all love Italy. Sadly, Brunella died prematurely, but others have joined our team. CHIANTI was first launched over 20 years ago and is regularly updated and improved. We are very proud of our achievement, and very happy that it is used so widely.

As an expert in solar space instruments, having worked on pioneering projects from the Skylab solar observatory to Hinode, what is the one instrument that you would like to see in space in 10 years’ time?

It has indeed been an honour to work on so many wonderful and exciting solar missions, with so many fantastic teams from the UK, USA, Europe and Japan. We have learnt so much about the Sun and the solar atmosphere, but we are still lacking a few pieces of the jigsaw. Of course, I love spectroscopy and what I would really like to see is further developments of complex instruments which combine spectra with high cadence imaging of the solar atmosphere. We’ve had a few examples already, with the early HRTS rocket instrument, and more recently with the superb IRIS solar observations. I’d also like to look again (as we did with the Solar Maximum Mission) at the soft X-ray wavelength region. We could then really get to grips with linking the theory and observations.

A lot of women in science are forced to make compromises between career and family. Did you have to make such a choice? And is there something you would have done differently given another chance?

Combining a career in science with family commitments is never easy, for a male or a female. I have been fortunate that my husband and the people around me have been very supportive. When I was working on SMM at NASA’s Goddard Space Flight Centre, my small children came with me. I was lucky that my sisters were keen to help out and have a free holiday. My solar colleagues have been hugely supportive, with words of encouragement when times looked bleak. I owe so much to the support from senior people (males and females) who believed in me and my abilities. I chose to work part-time for many years. This was a good decision, but not everyone recognizes that working part time does not indicate a lack of commitment, far from it. I have been invited to apply for Professorships at other UK universities, but this was not logistically possible with a family. I don’t regret my decision to stay in Cambridge. It is a wonderful place to live and work.

The OBE is indeed a great honor, in what way did this affect your –daily life –professional life?

The award of the OBE was indeed a great honour, but more so because someone had written a citation for me. You never know who or what they wrote, but the fact that someone did this, touched me deeply. It gave me more confidence in myself and the unconventional path I have trodden. Most of my peers (male and female) are now Professors. I probably could have been too, if I had made different decisions, but I have to say that very few of my peers have an OBE. It is awarded for ‘service’, and this means a lot to me. My OBE was awarded for services to higher education and women in STEM, which makes it very special. In addition, I was awarded it by the Queen at Windsor Castle, a place close to where I grew up.

You have worked extensively with young children and with graduate students. Which group do you prefer to work with? And do you notice a “generation gap” between these two sets of students?

I have indeed worked both with University students and school children. I have had several graduate students, have taught undergraduates. I am also a Life Fellow of St Edmunds College, and was a tutor, then Senior Tutor, so I have supported many students in different faculties, from all over the world. I still keep in touch with some, which is a great joy. 

I have worked with school children in the UK, South Africa and India. I lead the Sun|trek project (www.suntrek.org) which has been highly successful. Working with graduate students and with children is of course very different. I enjoy both. Yes, of course there is a generation gap. Children are now growing up in a very high-tech, consumer dominated world, where ‘celebrity’ is all about getting on a TV reality show. The pressures on children these days are immense, and many are suffering with bullying, depression, eating-disorders etc. This is a huge responsibility for our society.

As a woman of so many accolades, what was the one thing in your career that you consider a triumph but never got the acknowledgement you deserved?

Career-wise, I don’t seek accolades, but I do like the work I have done to be acknowledged. I have had a few significant press releases, and participated in media activities, radio and TV. I don’t think I have a ‘triumph’ which never got the acknowledgement which I thought it deserved.

It’s been a long fight for the cause of women in science, a fight that is far from over. Specially in some fields. What do you think about the drastically varying percentage of women in some fields Vs others. Are there lessons we should learn and use to improve things across the board?

Well, I think I could write a whole treatise on this topic. My view is that everyone has their own path to tread, all equally valid. The main issue is with perceptions, and this requires a cultural change. We do not all need to follow the same ‘standard’ career path. This is not an issue which just concerns women. I know men whose careers are suffering because of family commitments or other responsibilities. For couples in a relationship, a major issue is one of mobility, that is they need to find positions in the same location. This rarely happens, and one partner often has to compromise, possibly surviving for many years on ‘soft’ money. Males can find it equally hard to get funding and grants after a certain age, no matter how good they are. Technology should make it much easier to work remotely, which should make life easier, but doesn’t seem to yet. Part-time working or ‘time off’ still counts against you in job selection and promotion. Having a family is a commitment, which needs to be recognized. A work/life balance is important for males and females in our society. Attitudes need to change at the highest levels to provide more flexibility in our working patterns.

What is life after retirement?

I am still waiting to see what ‘life after retirement’ will be like. I hope to focus more on the things which I find fulfilling, my research and outreach work. I hope to start some new ventures and have more time for my family and friends. This is the theory, but I have not yet been able to put it in practice! I intend to do my solar research, and to be involved in future projects. I am also keen to link science and art. I lead an STFC funded project ‘SunSpaceArt’ which takes scientists and artists into schools. The children have produced some fantastic, creative and imaginative work. It is very rewarding to see how animated they get. I believe that STEAM, STEM with Art, is a good way forward for the future.

Helen doing what she loves. Right: with family, Middle: DAMYP Astro group at (Faculty of Maths) Open Day and Left: working with students in India