WeatherWeather Wise


Weather Wise: Aurora Borealis Forecasting

Weather Wise: Aurora Borealis Forcasting
Posted at 6:37 PM, Nov 01, 2021
and last updated 2021-11-02 12:23:00-04

HELENA — The coronal mass ejection, or solar storm, that happened this weekend was not as strong as first thought. One of the reasons meteorologists around the world missed the mark on the storm is that forecasting solar storms is still a young science.

Last week a large sunspot released a powerful solar flare in the direction of Earth. Initial estimation of the size, strength and direction of the flare indicated a strong likelihood of a strong aurora causing waves hitting the earth's atmosphere. Alas, to the disappointment of many that hoped to see the northern lights, that did not happen.

The activity picked up on Saturday evening before quickly fizzling, a sign that the earth only received a glancing blow. The northern lights made an appearance, just up north closer to the arctic circle.

Forecasting potential coronal mass ejections and their interaction with Earth can be very difficult. There is an enormous range of spatial and temporal scales involved, beginning with the heliosphere (the sun's atmosphere), the magnetism of the sun, then the strength and direction of the coronal mass ejection. Right now, it is not even known what physically causes these flares, so forecasters must wait until one occurs.

Using satellites and triangulation to measure the flares, a forecast is made. The best guess is made on a burst of solar radiation emanating from the surface of the sun that will travel 93 million miles to Earth.

The science of forecasting the aurora borealis is young but advances have been made in the last several years. Regardless as the sun enters a period of more activity, there will be more opportunities to see and forecast for the northern lights.