 Hello everyone, I am from Kharkiv and it's interesting for me that these lectures were started in my city and this is a good opportunity for me to take part in this mobilization of science. So I'm starting, I'm a scientist, I'm studying lightning in the Institute of Radio Astronomy and we have a department of Radio Physics of JSPACE in our Institute and we studied different phenomena in the atmosphere and ionosphere of the Earth and one of the most interesting of this and exciting phenomena is lightning. It is funny that we start our observation of lightning in Antarctica when there are no lightning at all. Why it's possible and why it's even convenient and I will tell you at the end of my lecture but now we will start with history. From the ancient times lightning was associated with power. Therefore the most powerful gods of thunder and lightning, Indra in India, Zeus in Greek, Jupiter in Rome, Thor in Scandinavian countries and Perun in Slavic countries. But now we know that it is not the power of gods. This is a natural phenomena associated with ordinary meteorological processes. Scientists explain lightning as follows. In the thunderstorm cloud, the combination of low temperature approximately minus 20 degrees Celsius and rapid upward movement of air led to a production of two types of particles, small ice crystals positively charged and more heavier grovels, soft hails and lighter ice crystals go to the top of the cloud and heavier grovels go to the go down and the separation of charge and after that it leads to discharge between the up and the down part of the thunderstorm cloud and this discharge consists of two stages. The first stage is so-called step leader. It consists of several small strokes and each of these strokes produce a long line with big ionization and then a return stroke occur. Their current go from this channel like in a wire. So there are two stages of lightning. Until the end of the 20th century, we think that lightning discharge occurred mainly between the ground between the ground and the cloud. But now we know that only 25 percent of lightning take place there and 75 percent of clouds are cloud to cloud and intra-cloud discharge. Also it's interesting that as for me that we thought that clouds that lightning occurs mainly not higher than 15 kilometers. But now we know several new types of lightning like blue jets which take place in stratosphere up to 50 kilometers and other types of lightning sprites and elves. Until now we don't know the exact model of this type of lightning and it is very interesting object for science now. Lightning is associated with optical flashes and thunder. It is interesting that it's possible to use these two effects as a simple diagnostic tool. Everybody knows that the speed of light is much higher than the speed of sound. So it's possible to calculate the time delay between the lightning and thunder and calculate the distance. Three seconds of delay corresponds to one kilometers and it's possible easier to calculate the distance to lightning. And also lightning produce not only the ordinary emission, optical emission, but also electromagnetic waves in a different range. Very long frequency radiation, extreme low frequency radiation. All of these emission is possible to use to diagnose the lightning, but we'll start with ordinary optical observations. And detection of lightning flashes, routine detection of lightning flashes started more than 100 years ago. Now every metallurgical station makes these observations and world metallurgical organization has a very big volume of data. And now this is a base knowledge of lightning for us. But with the start of the space era we can also study lightning from the space. This animation shows the map of distribution of lightning for different seasons. And it's possible to see that it is different from one season to another. But some things is ordinary for every season. First of all lightning mainly occur over the land. And there are three main sources of lightning, global sources. Asia sources, Africa sources, and America sources. And lightning also follow the sun. They mainly occur in the northern hemisphere during the summer. And during the winter period when the summer is in the southern hemisphere they move to the south. And it's possible and easier to see from this animation. But in spite of any capabilities of observations from space there are some difficulties. The main difficulties is the area of observation from the satellite is less than 1% of the Earth's surface. So this animation is the result of very big averaging. It's possible to see the behavior of lightning in general. But the real time picture is not possible to reconstruct from this data. There are other possibilities. One of these possibilities is using a very low frequency radiation. Very low frequency radiation. This is example of one of the best, the masterpiece, very good observation system, national lightning detection network of United States of America. There are 130 sensors located all over the United States. Its work in frequency range from 400 hertz to 400 kilohertz. And each sensor calculates the elements to the lightning and the time delay, the exact time of pulses. And if several sensors detect lightning, it's possible to locate lightning with accuracy about 200 meters. And it's very impressive results for me. And the detection efficiency is also very big. 95% for cloud to ground and up to 60% for inter-cloud lightning. And this is the best location system in the world. But the difficulties is the detection range is not more than 400 kilometers. So it's work only for United States. If you want to observe lightning around all the planet, you need to put all these sensors on this distance from one sensor to another in the net. You need to make a very big quantity of sensors, it's not possible now. So we in our institute use our technique for observation lightning, the mean average effect of lightning. This is so-called Schumann resonances. These resonances was predicted by Nikola Tesla in 1899 and then Otto Schumann in 1952, first time observed this effect. This effect is work in extreme low frequency range. This is the wavelength of this radiation is comparative with the surrounding of the earth. And each lightning produced electromagnetic pulse and these electromagnetic pulse rotate around the earth several times. For one second it can rotate eight times. So it's produced the maximum at approximately eight hertz. And the next one 14 hertz, next one 20 hertz and so on. And on each rotation it's amplify themselves. And this is like resonance. And this effect is possible observe at every place of the earth. For example, this is a picture which we detect in Antarctica at Ukrainian Antarctic Station. This is daily spectrogram. This is time from zero to 24 hours one day. And this is frequency from zero to 50 hertz. So you can see first, second, third and so on Schumann maximums. And you can see that the intensity of maximums in changing through the day. And it's possible to use mathematical model to calculate the changes of lightning in the three lightning centers. So it's possible in principle using one observation point observe all lightning around the world. And now we start this observation in 2002 in Antarctica. This is picture of our Antarctic Station, academic Vernadsky. And then we start to make the reservation in Arctic and in Ukraine. There are two things that can destroy this resonance picture. First things is local lightning. Local lightning produce very strong electromagnetic pulse and it destroy resonance picture. You can see this spectrogram which was taken in Ukraine. And it's possible to see these very big signals which destroy the resonance structure. The previous pictures show the resonance system in Antarctica. There are no interference signals. So the best place of observation in polar region. Another advantage of polar region is absence of artificial noise. There are no artificial noise in Antarctica. So our Antarctic records is have very good quality and it's possible to use it for different scientific tasks. I have no time to explain all these tasks, but I say only about one of these tasks. This is a possibility to use Schumann resonance giant tropical thermometer. The scientist from MIT, United States, or Williams at the end of the 20th century said that it's possible to use this signal as a thermometer. You can see this picture from his article in science journal. This heavy line correspond to surface temperature in tropics. And this light line correspond to intensity of the first Schumann maximum. You can see these very, these curves are very good correlated. So the Schumann resonance potential can show the changes of intensity from year to year, the intensity of lightning, which is good correlated with global temperature. Why is interesting to use these resonance and not to measure the temperature in a direct way? Because it is very hard to complicate global temperature, the average temperature. You can easily calculate the temperature at every meteorological station. This picture show the changes of temperatures in different places of the world according to meteor observation. You can see that in some region, you can observe increasing of temperature in other regions, decreasing of temperature. If you want to have the global picture, you need to average all this data and use some technique of calculation to calculate the changes of temperature. This graph show you the changes of temperature through the 1880 to the present time. But different curves correspond to different data sets and to different technique of calculation. And you can see that even now, when we have a lot of meteorological stations, it's not, these curves are different. So if you use a different type of averaging or different data sets, you take different results. But Schumann resonance automatically average all signals from all lightning. And this is one possibility. Of course, you need to use this traditional way of calculation temperature. But Schumann resonance can give additional information to do this. And if we take information from satellite, we'll try to measure temperature from satellite. You measure not the temperature of the earth's surface, you measure the temperature of the atmosphere from zero to approximately 15 kilometers. And it's different temperature. The warming in this part of gas sphere is not so quick as surface temperature. And according to some models, we can observe sometimes even cooling. So satellites cannot give us a lot now. But Schumann resonance can. Okay. And this is mainly all my lectures. I tried to explain that lightning is not only one of the best natural show of the world in the world, but also is very interesting and fruitful scientific tools for studying nature. And I am convinced that will bring us many new discoveries in the near future. Thank you. So if you have any questions? Speaking of your lecture, you mentioned lightning like events in the ionosphere at high altitude. And I'm wondering if there is very low air pressure there. So probably also very few water they work. So critically that there's not cloud or something else like cosmic ray particles or something like that. And these have any effect on those phenomena? I'm not a specialist in this field, but as far as I know, there is some initiative or one model of this effect is some initiative. This initiative is the ground lightning and there is some separation of charge between the lower atmosphere. For us, this is not lower. This is 10 kilometers or 15 kilometers. And for an atmospheric case, it's lower atmosphere and the ionosphere. There is some current in the ionosphere. So they initiated mainly by the ground lightning, as we think now. But of course, some other hypothesis is also a place to live.