Coronal hole faces Earth

Monday, 26 March 2018 13:17 UTC

This coronal hole looks deceptively large on the SDO/AIA 211 Ångström wavelength (Twitter insert below) but a closer look at the 193 Ångström wavelength (header image) reveals we are dealing with a southern extension of the northern hemisphere polar coronal hole. There is a very poorly defined equatorial portion but the 211 Ångström wavelength makes it seem more impressive than it really is. This shows why it is very important to compare the 193 Ångström and 211 Ångström wavelengths with each other, something you can easily do on our dedicated coronal hole page.

A transequatorial coronal hole is facing Earth. Enhanced solar wind could arrive in ~3 days. Follow live on https://t.co/bsXLidnzGh pic.twitter.com/eyfWsZkGyo

— SpaceWeatherLive (@_SpaceWeather_) March 26, 2018

We do not expect geomagnetic storm conditions from this coronal hole but with the equinox just behind us, and with a little luck this could again be another interesting event for high latitude (Scandinavia, Alaska, Canada etc.) sky watchers. The stream could arrive on 29 March and active geomagnetic conditions (Kp4) are possible.