For the past 2 years, Spaceweather.com and the students of Earth to Sky Calculus have been launching “space weather balloons” to measure cosmic rays in the atmosphere. Regular flights over California show that atmospheric radiation is intensifying in response to changes in the solar cycle. Now, our monitoring program is going global. In recent months we have been developing launch sites in multiple US states as well as South America and Europe. This is what the International Space Weather Ballooning Network looks like in October 2016:
Recent additions expand our coverage north of the Arctic Circle (Sweden) and closer to the core of the South Atlantic Anomaly (Argentina). We also hope to add a site in Antarctica in 2018.
The purpose of launching balloons from so many places is to map out the distribution of cosmic rays around our planet. A single launch site is simply not enough to reveal the nonuniform shielding of our planet’s magnetic field and the complicated response of our atmosphere to changes in solar activity.
Our first test of the network validated these ideas. During a 48 hour period from August 20th-22nd we launched 4 balloons in quick succession from southern Chile, California, Oregon, and Washington. The ascending payloads sampled atmospheric radiation (X-rays and gamma-rays) from ground level to the stratosphere over a geographical range of more than 10,000 km. Here are the results:
The curves show radiation levels vs. altitude for each of the four sites. Numbers in parentheses are magnetic latitude–a measure of distance from Earth’s magnetic equator.
At a glance we can see that atmospheric radiation is a strong function of magnetic latitude. Washington State at +53o has more than twice the amount of radiation as southern Chile at -29o–despite the fact that the Chilean balloon flew into the outskirts of the South Atlantic Anomaly. Clearly, Earth’s magnetic field provides very uneven protection against cosmic rays.
To explore these findings further, we are planning additional network launches every month from now on, adding new sites as often as possible. A launch from inside the Arctic Circle in January 2017 is highly anticipated. Stay tuned for updates from the Intercontinental SWx Balloon Network.