Viewing the Northern Lights is something I think everyone should get the chance to experience. I can remember the first night I went to photograph them. It started out as a green arc of light resting in the northern horizon. Then suddenly the green arc began to dance and wave and form pillars of color and light. The rush can be unreal. The hard part about viewing the Northern Lights is knowing when they will be active. Writing this blog post I want to help you increase your odds of when you should go out. Below is a website I want you to refer to in order to increase your chances of seeing them.
Space Weather Live is a website that tracks and predicts Northern Light activity. I get two questions a lot. What are the Northern Lights and when will they be active? The first answer is much easier to answer than the second. The Northern Lights are a result from charged particles (that have been launched off the sun) interacting with our magnetic field. They happen when the sun either has a solar flare explosion that is sent in our direction or when there is a high speed solar wind stream that is bearing down on us. The website above tracks everything from what the sun is doing and predicting when conditions will be right for Northern Lights to giving updates on when the Northern Lights are active. It is a very data driven website which can be overwhelming to the beginner. I want to teach you how to read the charts and graphs so you can determine when it would be worth heading out and viewing the Northern Lights.
The above link will take you to the solar wind dials. You will see something similar to the photo above with the graphs. The solar wind dials are one of the best ways to predict how active the Auroras will be. Lets start out with Solar Wind Speed. This measures how fast the charged particles are moving. Ideally 400 km/sec or more is ideal. This will help turn the green arc into dancing pulsing pillars of light. Solar Wind Density is how dense the particle cloud is. The higher the density the more saturated the colors. A density of 10 p/cm^3 or higher is ideal. Next is Direction of the Imf or Bz as we like to call it. This measures how far south the Northern Lights will be visible. This is one of the most important attributes. The more negative the number the better we have a chance at seeing the Northern Lights. Being here in Wisconsin a Bz of -10 Nt is ideal. Next is Strength of the IMF or Bt. This measures the overall strength of the storm. Again here in Wisconsin a rating of 10 nT is ideal. You can learn more about these features by clicking on the ? Help box next to More Data below each table.
Short Hand List Of Ideal Settings For Latitude 45 and -45
Solar Wind Speed 400 km/sec or above.
Solar Wind Density 10 p/cm^3 or higher.
Direction Of IMF Bz -10 or lower.
Strength of IMF Bt 10 or higher.
For latitudes further north than 45 these settings do not have to be as high to see them. If you live further south than latitude 45 depending on how much further south you will want these settings to be much higher. For latitudes further south than -45 these settings are ideal and yet depending on how much further south you are the settings do not have to be as high. Going further north than latitude -45 you will want an increase in these solar dials.
The next set of data I look at when determining if I should head out to view Northern Lights is by looking at the Aurora Ovation Map. Above is a link to a live view of the Ovation Map. It can be found under the Aurora Activity tab in the navigation menu. This chart shows forecast predictions of how intense the Northern Lights will be. That green band is the Northern Lights, now there is also a View Line. The view line is not 100% accurate, but if it is hovering over Lake Superior, being in Wisconsin, it might be worth checking out. The most important feature of this map is in the upper right hand corner. In yellow lettering you will see Hemispheric Power, and on this map it says 22.79 GW. This is also one of the key features to determine if it would be worth going out to see the Northern Lights. I would suggest for Wisconsin a minimum of 30 GW, anything higher than 30 GW is definitely worth checking out. Right now the band is green, which means the lights are active but they aren't active enough to see in Wisconsin. Now if you were to look at this map and you started to see in that green band colors such as yellow, orange, and red you definitely want to get outside. Orange and red indicate intense activity.
The Aurora Forecast will give you predictions several days out. They refer to a Kp value which will help determine the Geomagnetic conditions. Essentially this measures how strong the storm is. This is not entirely accurate and I personally don't base when I should go out to view the Northern Lights based on Kp values. Yet by looking at the forecast it does help me determine the days I should be paying close attention to the wind speed dials and ovation map. Keep an eye on the forecast to determine when the Northern Lights are predicted to be active. It gives a 3 day forecast which will help with planning. The time is given in UTC so you will have to adjust it to your time zone. For example I live in CST so we are -5 hours making the lights visible between 00 and 09 on this chart. That would put us in the right part of rotation and give us the longest part of the night for optimal viewing.
For better predictions we can turn to the Solar Activity tab in the navigation menu. This is going to show you data of what the sun is doing. By paying close attention to the sun you can determine when there will be a solar flare or a high speed solar wind stream that will head towards Earth. On the above graph you will see a dot to the right. That green dot is Earth. The center yellow dot is the Sun. You can see bands arcing out from it in green turning into yellow, orange, and red. These are high speed solar windstreams. These carry a dense amount of charged particles that can cause the Northern Lights to become active. What is not shown is a flare. A flare would act as a projectile launching off the sun. When one of these launches off in our direction it will interact with our magnetic field causing the Northern Lights to become active. The sun does rotate, which can make it tricky for everything to line up just right for conditions to come together.
Another question I often get asked is where can I go to view the Northern Lights? Above is a link to a website that will show you a heat map that displays Light Pollution. What you will want to look for is yellow, green, blue, grey, or black areas to view the Northern Lights. Remember your view is to the North and any cities in the way of your view looking north will make it difficult to see the Northern Lights. I try to avoid white, red, and orange areas to the north of where you will be viewing. You will also want to pay attention to moon phase. The fuller the moon the more difficult it will be to to see the Northern Lights. Pay close attention to the moon phase and when the moon will rise and set to determine when to get out and view the Northern Lights. I hope this helps you find a dark sky to view the Northern Lights.
NOAA Sky Cover Map is a great prediction indicator for how clear the skies will be. It has the ability to predict several days out and has been a very reliable source of data. So if you are wondering what the clouds are doing and if the skies will be clear this is a good start.
Satellite imagery provided by a geostationary satellite allows us to see real time data and images of what the cloud cover is doing in our area. This will allow you to determine after checking NOAA Sky Cover how clear the skies really are. Which will help you determine if it would be worth your time to get out and enjoy the Northern Lights or will you only see cloud cover.
Above is a link to a cloud cover map for most of Europe, Russia, New Zealand, and parts of Asia. This should help with aurora viewing in those areas.
Windy TV is a new website I came across for weather predictions. It is fairly accurate giving you an idea for predicting what cloud cover is going to do. I highly suggest still checking out a Geostationary Satellite Image for a high definition image that you can help you determine real time cloud cover.
I hope the above information was helpful and that it will help you determine when it will be possible to view the Northern Lights. You can also get notifications by following Space Weather Live on social media. They will post alerts and notifications in their Facebook and Twitter Feeds. Another great resource is by becoming a member of the Great Lakes Aurora Hunters on Facebook. They are a group of people interested in viewing the Northern Lights. By being a member you will get posts from other members when they will be active. Thank you for reading my post and remember to hit subscribe at the bottom of my website to subscribe to my email list. By subscribing you will be notified when I make helpful blogs such as this and when I run discounts on my prints. Thank you!