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AURORAS BOREALES 2013 1

The Northern Lights 24-29 August 2013 (00:30-1:30 UT), Greenland (Denmark)

The Phenomenon Year 2013: Maximum in solar activity. According to latest predictions, the Sun will start its 24th period of solar maximum before the end of 2013. Solar activity is defined by the number of sunspots detected on the surface of the Sun. As we approach the maximum, the number of sunspots increases, as shown in Figure 1. Additionally the magnetic poles of the Sun flip. Observational data tell us that this is happening right now (mid August).

Figure 1. Solar activity plot for the past 13 years (sunspot number against time). The first maximum corresponds to the last solar maximum (2001). Predictions indicate that the next maximum will occur before end 2013. Credits http://sidc.be. From observational data collected during the last 200 years, it is known that the solar maximum (maximum of sunspots) follows a cycle of approximately 11 years (see Fig. 2).

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Figure 2. Solar activity during the last 50 years (number of sunspots on the surface of the Sun against time). One of the consequences of the solar maximum is that the Sun increases the emission of very energetic elementary particles (solar wind) in what is called a solar storms. The main effects that the solar maximum has on Earth are: 1. Interference problems in communications networks (terrestrial and satellites). 2. Possible problems with electricity supply due to the massive arrival of electrons at the terrestrial

surface. 3. Possible effects on the terrestrial climate. 4. Increase in frequency and luminosity of polar auroras (Northern/Southern Lights). During the 1989 solar maximum, intense solar storms caused serious problems with electricity supply to several cities in the north of the United States and Canada. Several satellites also suffered temporary anomalies in the course of these storms. The relation between solar activity and terrestrial climate has been a subject of debate in the last few years. There are indications suggesting that Earth is cooled down during solar activity minima. Moreover, a prolonged solar minimum occurred between the years 1645 and 1715 (the Maunder minimum, see Fig. 3) and it is believed that this caused a small ice age, with effects that manifested in Northern Europe.

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Figure 3. Solar activity during the last 400 years (number of sunspots on the surface of the Sun against time). During the solar maxima the intensity of the solar wind increases, leading to an increase of flux of elementary particles arriving at Earth. In fact Earths magnetic field channels these particles towards the magnetic poles where they collide with the atoms and molecules of the atmosphere, causing the Aurora Borealis (Northern hemisphere) and the Aurora Australis (Southern hemisphere). The best zone to observe the Aurora Borealis is in a circle around the magnetic North Pole, between 60 and 70 degrees North. However the magnetic pole does not coincide with the geographic North Pole and moves over time. It is currently located off the coast of the Canadian island of Ellef Ringnes, meaning that southern Greenland is an excellent location to watch the auroras. Auroras As mentioned, this wonderful celestial spectacle takes place when very energetic particles from the Sun reach the Earths atmosphere via the solar wind. The entrance of these particles is governed by the Earth's magnetic field and, therefore, they only can penetrate through the atmosphere in regions close to the North Pole (Aurora Borealis) and the South Pole (Aurora Australis). The auroras can be of different types. Sometimes they consist of luminous curtains, which change quickly and show several colors. The light emission takes place in the region of the atmosphere called thermosphere, at altitudes between 100 and 400 km, and it is a consequence of the collision of the solar wind (essentially electrons) with atoms of oxygen (greenish tones) or nitrogen molecules (reddish tones). During 2011 and 2012, a period of increased solar activity, intense auroras were detected (see Fig. 1). Expedition-Location

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The Shelios 2013 expedition (see more information at http://www.shelios.com/sh2013a) is promoted by the scientific-cultural association Shelios and its coordinated by its president Dr. Miquel Serra-Ricart (Astronomer of the Institute of Astrophysics of the Canary Islands). The main objective of the expedition will be the observation and images collection of the Aurora Borealis from the South of Greenland in a period of maximum solar activity (see Fig. 1).

Figure 4. Encircled numbers (1,2,3) mark areas from where the observations and live broadcast of the Aurora Borealis will be carried out. Broadcasting There will be a daily broadcast, whenever weather conditions allow it, between 24 and 29 August 2013, from three different places in the south of Greenland (see Fig. 4). The location 1 is situated in the surroundings of the Qaleraliq glacier (longitude = 46.6791W; latitude = 60.9896N, Fig. 5), the second in a farm of Tasiusaq (Fig. 6), and the third in the village of Quasiarsuk (Hostal Leif Eriksson, see Fig. 7). The broadcasts will be when it is night time in Europe and will last one hour, between 00:30 to 1:30 UT (22:3023:30 local time of the previous day in Greenland, 2:303:30 CEST; where UT means Universal Time and CEST Central European Summer Time). The event will be broadcast on the website live.gloria-project.eu and will be performed at two levels: 1) Live Connections

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Live broadcast using a black and white video camera pointing to the sky with the aim to show the actual movements of the aurora. 2) Time-Lapse During the live broadcast and every minute, two color images of the starry sky will be posted to the mentioned website. The two images will be obtained at the same time by two Canon 5D Mark II color cameras equipped with identical lenses and placed at two locations some km apart (the maximum distance would be 50 km). These images will be accessible from the website and will allow students to calculate the height of the aurora using the parallax method (details can be found in the activity manual).

Figure 5. Site camp at the Qaleraliq glacier. It will be the main broadcasting location (marked 1 in Fig. 4, J.C. Casado-starryearth.com).

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Figure 6. Tasiusaqs Farm, the second location of the broadcasts (see Fig. 4, J.C. Casado-starryearth.com). The broadcast can be followed either from the GLORIAs portal live.gloria-project.eu or the portal of the principal contributor sky-live.tv. The GLORIA portal will also display updated weather information and any change in the schedule of the broadcast. The broadcast will be advertised on several website and, additionally, a few hours in advance via GLORIAs social networks.

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Figure 7. Aurora Borealis seen from the town of Quasiarsuk, southern Greenland, on late August 2011 (location 3 in Fig. 4). The image was taken during the expedition Shelios 2011 (see shelios.com/sh2011, D. Padrn- starryearth.com). Educational Activity With the images taken during the expedition we will propose to perform the following educational activity: Calculation of aurora altitude from images using color and parallax methods. See the event dedicated web page on the GLORIA website gloria-project.eu for more information. Links During the broadcasting we will have daily information on the solar activity through the following nodes:

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Latest solar images in different wavelengths from the SOHO Satellite (international cooperation between the ESA and NASA space agencies): http://sohowww.estec.esa.nl/data/realtime-images.html

Solar Activity and forecast:

Europe: http://sidc.oma.be/index.php3 United States: http://www.sec.noaa.gov/SWN/

Credits The Seventh Framework Programme of the European Union (EU, FP7/2007-2013, INFRASTRUCTURES-2011-2, INFRA-2011-1.2.1: e-Science environments) collaborates with the broadcast through the GLORIA project GLObal Robotic telescopes Intelligent Array for e-science (Grant Agreement Number 283783).

Video collaborators

Web collaborators

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Will participate to the web distribution: - National Institute for Astrophysics (INAF) IASF Bologna - Institute of Astrophysics of Canary Islands (IAC) - Warsaw University - Oxford University - Supercomputer Center of Catalunya (CESCA) - Alared Web Solutions - Canarcloud company - HEAnet from Ireland - Astronomical Institute of the Academy of Sciences of the Czech Republic - University College Dublin, Ireland

Further Collaborators

- The Army, Canary Command collaborates in satellite communications. - Tasermiut South Greenland company collaborates with logistics in Greenland.