Dunedin Aurora

2020 Edition

Coronal Hole Solar Wind Forecast

Version 1.0

Based on Empirical Space Weather Forecast Tool by University of Graz.
SDO image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

SDO 193 Å EUV Image

NOAA SWPC Syntopic Map

DunedinAurora.NZ computer generated CH Map



Coronal holes are natural openings in the solar atmosphere that allow fast flowing streams of solar wind to fan out. When these streams hit the earth they squish our magnetic field and can cause auroral displays. There is a correlation between the size of a coronal hole and the intensity of the solar wind hitting the Earth. At Dunedin Aurora, we have created a computer program that calculates this relationship between coronal hole size to solar wind speed. Once we know this, we can calculate the arrival time of any space weather strong enough to cause an aurora.


Linear approximation is: Predicted windspeed = 342.84 + 327.76 * coronal hole area on meridian
Pearsons correlation |r| = 0.1957
Average Windspeed is 351.7km/s
Space weather transit time is 4.9 days