Forskningsexperiment AZURE

Questions and answers about IRF’s scientific experiment with a sounding rocket

IRF space scientists answer questions about the sounding rocket experiment that creates colorful clouds for aurora studies, which is carried out as part of the IRF research program Solar, Space and Atmospheric Research.

What materials are used and how much is released at high altitude?
The most commonly used tracers are barium, lithium, and tri-methyl aluminum (TMA), which is an aluminum compound. In our experiment, eight canisters will be used and each canister contains approximately one kilogram of barium.

Is the material harmful to people, animals or our atmosphere?
No, the small amounts of trace vapor emitted into space are not harmful to humans or animals on the ground, nor to our atmosphere. The vapors used as tracers are the same metals that are used much more extensively in regular fireworks.

A typical New Year’s firework releases many times more of the substances and is much closer to the ground.

Why is this scientific experiment necessary?
People want a good mobile connection and good HD TV and we all want to avoid power outages. All these phenomena are strongly dependent on space weather because the powerful processes in near-Earth space driven by solar activity can result in a satellite disaster and the breakdown of the power and pipelines on the ground.

Therefore, an understanding of the physical processes involved in space weather is very important for human societal development and also makes a significant contribution to the fundamental science progress.

The aurora is a beautiful manifestation of space weather that is visible from the ground with the naked eye. Studies of the aurora and the upper atmosphere and ionosphere in the aurora region provide invaluable information about space weather processes.

The light phenomenon and the properties of the ionosphere will be observed using the IRF’s optical cameras developed for aurora studies, as well as with radar measurements contributed by the EISCAT Scientific Association.

A sounding rocket of this kind makes it possible to observe the movement of the neutral and charged atmospheric particles, which provides important information about the electric field and currents in near-Earth space.

The altitude that the sounding rocket reaches allows us to locate electric fields and currents that are in the range of 100-150 km. This height cannot be reached by airplanes or satellites, but only by rocket.

What are the scientists looking for in the colorful clouds?
Some of the barium particles released into the upper atmosphere are ionized very quickly by solar radiation. Both neutral and ionized barium particles can emit bright light of various colors visible from the ground, similar to the aurora.

Observations of the motions of the neutral and ionized barium clouds provide information on the electrodynamics of the auroral ionosphere. This information is critical to understanding space weather processes.

Is the amount of substances released toxic?
No, it is not. The eight kilograms of barium released at an altitude of 100-200 kilometers will spread over a huge area, on the order of 300×300 square kilometers, before it reaches the ground. This means that the amount falling on the ground is on average less than 0.01 micrograms per square meter.

Have similar experiments been done before? Where?
Yes, similar experiments have been conducted since the early 1950s. In recent decades, interest in chemical release experiments in the atmosphere has increased due to access to new and advanced optical instrument technology.

A number of similar experiments have been conducted from the rocket base in Andøya, Norway, over the past four years. At the same time as the IRF experiment is being carried out, an experiment called VortEx will take place in Norway.

Why is the sounding rocket launched from Esrange?
IRF has a good collaboration with SSC Esrange, and the Esrange space base is probably the best place to conduct this experiment from. Esrange is surrounded by good research infrastructure and instruments for basic research in geophysics. These are facilities that we need for the experiment and are not available at other rocket sites in the polar region.

I live in Kiruna and want to see this in the sky. Where is the best place to be?
The campaign for this experiment runs between March 12-22. The night on which the launch takes place depends on weather conditions and aurora activity. The sky must be clear and the wind minimal. The rocket can thus be launched any evening during the specified dates and the launch will take place shortly after sunset, between half past six and half past eight local time.

The colorful barium clouds should be visible from any location with clear weather within a distance of less than 200 kilometers from Esrange.

Contact person:
Johan Kero, head of IRF’s research program Solar, Space and Atmospheric Research.

Photo: Lights over Lapland
Caption: Similar scientific experiments for aurora studies have been done, for example, by NASA from the Norwegian space base on Andøya. Northern lights cameras in Abisko captured the colorful clouds.


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