 I'm Luke Barnard from the University of Reading and I'm a space weather and space climate scientist. So I've been working within space weather for five years and probably one or two of those years has been spent focusing on space climate. So I started off looking at actually the statistics of pseudo-analytic particle events which are radiation storms which are damaging to satellites and our health hazard to astronauts and aircraft crews and they also have some geophysical interactions in the upper atmosphere but as part of that we wanted to look at kind of longer timescale so we moved to looking at space climate studies and now I actually am kind of purely a space weather scientist looking at corona mass ejections and the slow solar wind. Corona mass ejections are larger options of plasma from the solar corona out into the solar wind. They are things that we are worried about on Earth. So corona mass ejections have a magnetic field and that magnetic field can interact with Earth's magnetic field when the corona mass ejection propagates through near Earth's space and depending on the configuration of the magnetic field in the corona mass ejection and the state of Earth's magnetosphere this can lead to a geomagnetic storm and geomagnetic storms can be troublesome for certain kind of technological systems they can cause disruptions to GPS signals on the Earth and they are also a technical problem for power grids. My boss here was part of a team of collaborators from several different institutions who put together a citizen science project which allowed the public to take part in tracking corona mass ejections in images from the stereo satellites. The stereo satellites are, well there's one ahead of the Earth and one behind the Earth and they have two cameras which are designed to image the the plasma moving from the Sun to the Earth and in those you can see corona mass ejections leaving the corona and expanding out through the heliosphere towards Earth. So solar storm watch consists of several activities where interested participants can identify corona mass ejections visually in movies taken from the stereo satellites and then they can also track these corona mass ejections going out through the fields of view of the cameras and then what we do is we statistically reduce all of these observations into periods where there was probably a corona mass ejection and so we we move away from using kind of one expert to say there was a corona mass ejection here to saying there were lots of people who think there was a corona mass ejection here. This all runs from the solar storm watch website and all of the activities are available via online web interfaces. So for example in the first activity a short movie is loaded up which shows the view from the stereo satellite ahead of the Earth and the stereo B satellite behind the Earth and then you view this movie and when you think you have seen something which is a corona mass ejection you say pause the movie here it registers the time and then you follow that movie backwards to say when when did it first enter the field of view and that gives you an idea of when you think the corona mass ejection was erupting. There's over 16,000 people that are registered on the kind of the solar storm watch citizen science project website and over 5,000 of those have been kind of following out these corona mass ejections out through the heliosphere and so we've reduced all of their observations into a catalog of corona mass ejections but that's what I've been doing recently and then the other side of my work is trying to use the stereo satellites to look at the the evolution of the solar wind near the near the outer edge of the corona. So the stereo satellites have been flying since 2007 and so we're looking at kind of short-term space weather style variations in the solar wind rather than long-term change. Well so we know from both satellite observations and reconstructions of solar activity that the Sun varies on many timescales. The most prominent timescale that people are familiar with is the 11 year solar cycle which is well known from the Sunspot record. There's also the the hail cycle which is an approximately 22 year periodicity which reflects the Sun's magnetic activity cycle but if you look to the cosmogenic radionuclide record of solar activity which extends several thousand years we see that it also has longer periodicities of the order of hundreds of years to a thousand year periodicities. So we've been able to measure solar activity and in particular the the solar wind in near Earth space since the early 1960s with direct satellite measurements. We're also able to infer information about solar activity on longer timescales before we had satellites from geomagnetic activity records and also the the cosmogenic radionuclide record. So galactic cosmic rays are energetic charged particles which enter the solar system, sorry travel through the solar system towards Earth. When they reach the top of the atmosphere they undergo nuclear reactions and produce what we call cosmogenic radionuclides such as beryllium-10 and carbon-14. These are specific radionuclides which are only produced by the galactic cosmic rays interacting on the top of the atmosphere and then they are stored in geophysical reservoirs so for example carbon-14 takes part in the carbon cycle and ends up fixed into for example tree rings and beryllium-10 is eventually precipitated down into the ice and so ice cores and tree cores can tell us about historical concentrations of beryllium-10 and carbon-14 but the amount of galactic cosmic rays which reach the top of the atmosphere depend on the level of solar activity and so as we look at the concentration of cosmogenic radionuclides back in time what this can tell us is about how solar activity has varied back in time. So we haven't constructed the records we've used data that was published by other people but they have analyzed a suite of ice cores taken from both the northern hemisphere and the southern hemisphere and also records of the concentration of carbon-14 taken from tree rings and they've analyzed all of these data sets to look for the common solar signal in it because of course carbon-14 and beryllium-10 are processed differently in the atmosphere and so their journey through the earth system into the geophysical reservoir is different but in both of these signals there is a common solar signal and that tells us about how active the Sun has been and so they have analyzed all of these different records to come up with a consensus profile for how solar activity has changed and how the flux of galactic cosmic rays reaching the top of the atmosphere has changed back in time that extends back roughly 10,000 years the space age has coincided with a period of larger than average solar activity and so solar activity is what we have been calling in a grand solar maximum over the space age and that actually if you look back through this 9,300 year record of solar activity taken from the cosmogenic radianuclides what you see is there have been 24 or 25 similar episodes in the past and if you look at the the length of those episodes when solar activity is above a certain threshold what you see is that the space age has actually been a very long period of grand solar maximum and that statistically if you would assume that what has happened in the past is likely to be similar in the future that this period of grand solar maximum is due to come to an end and that actually the most recent observations of near-Earth space show that there has been a decline in solar activity over the last 20 years. The Earth's magnetic field responds to variations in the solar wind in near-Earth space there's a worldwide magnetometer network which records variations in Earth's magnetic field and with an understanding of how the Earth's magnetic field responds to variations in the solar wind we can use the records of geomagnetic activity to infer what goes on in the solar wind and we have a reliable records of geomagnetic activity back to around 1840. We try to produce a forecast of solar activity from a statistical perspective by looking back at these previous 24 grand solar maximums and saying what happens if we look at the range of scenarios when we exit these grand solar maximums and so we performed what's called an analog forecast where we take these 24 periods we stack them all on top of each other and then we take the average of these and say what happens to on average when we leave the grand solar maximum and what this showed is that solar activity is likely to decline in the future for the next over the next 50 to 100 years. We came up with three scenarios for our forecast where we looked at the average decline and then also a likely minimum decline and a likely maximum decline from the grand solar maximum. What this showed is that of the 24 previous grand solar maximum two profiles reached more than minimum conditions within about 50 years and so we estimated that there was roughly an 8% chance that we could see more than minimum like conditions in the next 50 to 100 years. So the minimum was a period of very low solar activity when very very few sunspots were counted which was several hundred years ago. A sunspot is a region of enhanced magnetic flux on the surface of the Sun and this causes a localized cooling of the plasma which means it's less bright and appears darker. The edges of sunspots are actually brighter and that there's an imbalance the brightness sorry the brightening at the the edges of sunspots outweighs the darkening in the sunspots. So I was a master student on a just a general physics degree. I hadn't chosen to specialize in anything in particular because I was just kind of broadly interested and then I took a lecture course on solar terrestrial physics and it piqued my interest and yeah I was lucky enough to be offered a PhD doing space-weather science and I've been doing it ever since. I think the most interesting scientific questions or big questions that still need to be answered at the minute regard a better understanding of the solar dynamo. This is something that I'm not working on. It's about developing an understanding of the solar magnetic cycle and how that evolves in time. It's something that I think is very important. It's something that I'm interested in. It's not something I actively do that much. I think it's about showing the interest and the excitement of doing the science.