Category Archives: atmospheric science

Your Friend, the Ionosphere

Comes to a GoogleEarth Program Near You!

The ionosphere — it’s a layer of ionized gases at the top of Earth’s atmosphere, and something we don’t think about too much unless it gets all muddled up by disturbances from the Sun. When that happens, we see auroral displays and also can experience periodic outages in radio communications, GPS reception, and power systems.

Ham radio operators use the ionosphere to “propagate” radio signals around the world, and as it turns out, so do aircraft that fly over the poles (and out of reach of communications satellites). There are a great many scientists around the world who study the ionosphere, including the people I work with at MIT Haystack Observatory.

Now, through the auspices of the Communication Alert and Prediction System folks, you can explore a 4-D model (visualization) of the ionosphere using GoogleEarth.  Today, at the Space Weather Workshop in Boulder, Colo., NASA-funded researchers released to the general public a new “4D” live model of Earth’s ionosphere. Without leaving home, anyone can fly through the dynamic layer of ionized gases that encircles Earth at the edge of space itself. All that’s required is a connection to the Internet. Airline flight controllers, for example, can use this tool to plan long-distance business flights over the poles, saving money and time (and boosting safety) for flyers.

In a kind of cool “blast from the past” I note that an old friend and graduate school officemate of mine, Lika Guhathakurta (a NASA solar physicist) was the one doing the announcing in Boulder. So, go read about the ionosphere at the links above, and then check out the latest ionospheric data and see what’s fascinating Lika and the other astronomers who make it their business to study the ionosphere!


Looking Down the Old Coronal Hole

Feel the Breeze?

The Solar and Heliospheric Observer sent along a picture of a huge coronal hole that’s opened up on the Sun recently (it’s that dark area to the upper right of the three sunspots and their associated magnetic fields.

There’s a brisk solar wind breeze blowing out from this hole, which will buffet Earth’s upper atmosphere for a while. This image shows the Sun in extreme ultraviolet wavelengths. The Earth is right smack in the center of the breeze, which is causing some nice auroral displays at high latitudes. What’s happening is that high-speed plasmas in the solar wind are colliding with the upper part of our atmosphere and our magnetic field. This heats the gas molecules up there and causes them to glow.

Here’s a nice image on Spaceweather.com, taken by Sylvain Serre in Nunavik, Quebec that shows what happens when the solar wind smacks our upper atmosphere around. Serre and some friends were out viewing the sky when the auroral display started up and basked in the glow for while. There’s a good chance that there’ll be more auroral displays the next couple of nights, so if you live in an area where such things light up your sky, check ’em out!