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Falls Dam

Home Hills run

Falls Dam

Falls Dam

Wedderburn

Moa Creek

Patearoa

Middlemarch

You can see other photos from this trip in my fine art photo gallery here:

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Some trip photos also by Andy Woods & Dan Childs.

Reviewing the Data in Hindsight

Also written in hindsight of the event, the week later, Benjamin Alldridge wrote on the Southern Hemisphere Aurora Group Facebook page

“Those of you who caught the majesty of the aurora: you have witnessed once in a century conditions. Last time we had this level of activity in one 24 hour period was early in the last century. In terms of absolute magnitude, we peaked at -412nT DST (essentially the level of “agitation” the magnetosphere has experienced), the greatest since the 1989 solar storms that took down the entire power grid of Quebec, which was on paper about 20% bigger but lasted for a shorter amount of time. We had confirmed captures in FNQ near Cairns, New Caledonia, and Florida – about 6,000km from the geomagnetic poles. People captured it in most major cities on the planet, and saw it clearly in many others. Even Africa and South America didn’t miss out, which is unprecedented in modern times”.

I have since read another post by Ian Cooper on the Aurora Australis NZ Facebook page, that I will post and credit fully here:

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Cheat Sheet of Best Settings for Southern Lights Photography

The aurora can vary in intensity, movement, and color, so having a starting point can be incredibly helpful.

Here’s a cheat sheet that you can adjust based on specific conditions:

1. Image format: RAW. This format captures more detail and allows you more flexibility in post-processing.

Using Manual mode (M) on your camera is crucial for northern lights photography due to the unique and variable lighting conditions you’ll encounter.

Here’s why you should use Manual mode (M) for your aurora photography:

• Complete control. Manual mode (M) hands you full control over aperture, shutter speed, and ISO. The aurora’s brightness can fluctuate rapidly, and Manual mode allows you to respond to these changes immediately without relying on your camera’s guesswork.
• Consistency. It helps maintain consistency across your shots. Automatic modes might produce varying exposures due to the camera’s metering getting confused by the dark sky and bright aurora. Manual settings ensure that once you find the perfect exposure, it stays consistent across your shots.
• Creative freedom. You can decide the visual outcome of your shot. Whether you’re aiming for a perfectly exposed aurora against a dark sky or wanting to capture the landscape’s silhouette against the aurora, Manual mode (M) allows you to make these creative decisions.

By controlling every aspect of the lightness, you can adapt to the aurora’s variability and express your creative vision.

Choosing the RAW image format for souhern lights photography is a strategic decision that significantly impacts the post-processing flexibility and overall quality of your final images:

• Unlike JPEG or other compressed formats, RAW files capture all the data from the camera’s sensor without any in-camera processing or compression.
• The dynamic range in a RAW file is significantly higher than in a JPEG file, meaning it can store more information about shadows and highlights. This is crucial when photographing the northern lights, as you can recover more detail from dark foregrounds and bright auroral displays during post-processing.
• You can adjust the white balance post-shooting to accurately represent the colors you saw, or creatively enhance them for artistic effect.

This choice is particularly advantageous for the challenging lighting conditions and dynamic range found in aurora borealis scenes.

2. Stabilization: Off. Turn off any image stabilization when using a tripod to avoid unintended blurring.

Image stabilization, whether optical (OIS) or sensor-shift (IBIS), is designed to compensate for camera shake, making it invaluable for handheld shooting. However, when your camera is securely mounted on a tripod, keeping stabilization activated can inadvertently introduce blur.

That’s why turning off any form of image stabilization (IS) when your camera is mounted on a tripod is a nuanced yet essential practice in aurora photography.

3. Camera mode: Manual (M). This gives you complete control over all settings.

4. Aperture: f/2.8 to f/4. Use the widest aperture (lowest f-number) your lens allows to capture as much light as possible.

When it comes to photographing the northern lights, your primary objective is to capture as much of the elusive aurora glow as possible. Achieving this begins with one critical camera setting – your aperture. The aperture controls the amount of light that reaches your camera’s sensor, and in the dim conditions of night sky photography, every photon counts. To maximize light intake, set your lens to its widest aperture. Fast lenses, those with maximum apertures of f/2.8 or wider, are ideal for aurora photography.

However, wide apertures come with a shallow depth of field, which can leave elements of your foreground out of focus if they’re too close to the lens. In such cases, consider employing techniques like focus stacking, where you combine in post-processing multiple images at different focus points to achieve a uniformly sharp scene from foreground to stars.

If your lens doesn’t open up to f/2.8 or wider, don’t worry. Open it to the widest aperture available, and adjust your ISO and shutter speed accordingly to compensate for the reduced light intake.

Remember, the goal is to let in as much light as possible without compromising the quality of your image with excessive noise.

5. Focus: Manual, set to the hyperfocal.

Autofocus can struggle in the dark. You can focus on an area pre-darkness if you arrive early. Otherwise if in darkness, focus manually on a distant light in the distance. Otherwise you can try hyperfocal focusing.

Watch a video that will help you focus to the hyperfocal distance in the dark. You can calculate the hyperfocal distance very easily with the PhotoPills depth of field calculator.

Note: If the main subject is at a greater distance than the hyperfocal distance, you should focus directly on the subject. You will lose some depth of field in the foreground but everything that is at infinity will remain focused and the subject will be tack sharp.

The other key means to focus if set up in the dark is to use your camera’s live view feature if it has it, to focus manually.

1. Aim at a bright star or distant light.
2. Zoom in using the live view’s digital zoom feature.
3. Adjust the focus until the star or light is as small and sharp as possible.

One of the problems we face at night photographing the aurora, is we are shooting with maximum aperture. By default this does restrict our depth of field, so can ge a bit tricky. If you have interesting foreground elements you wish to include and they are not at infinity, consider using a technique called focus stacking. Take multiple images with different focus points—from the foreground to the aurora—and blend them in post-processing to achieve an image that’s sharp throughout. Sometimes you may wish to take a photo with any foreground subject focused, to allow choice stacking your focus later in post production.

6. Shutter speed: 

You need to be careful with your shutter. Both to gain a good exposure, but to minimise star blur, and to preserve any aurora pillars. In essence you need to keep the shutter speed as short as feasible. Shorten for more intense auroras or to capture finer details and lengthen for fainter auroras. The reality is your shutter will still be long in everyday terms – between 5-30sec.

• Faint and static aurora. For auroras that are barely visible and relatively stationary, a longer exposure, closer to the 25-30 second mark, can help gather enough light to make these subtle displays visible in your photos.
• Vibrant auroras. When the aurora is clearly visible and showing moderate movement, aim for a shutter speed between 8 and 15 seconds. This range strikes a balance between capturing the movement of the aurora and keeping the stars as sharp points of light.
• Intensely active aurora. For those moments when the aurora is dancing rapidly across the sky, a fast shutter speed of 1-10 seconds is key. This setting helps freeze the motion of the aurora, capturing the intricate details and preventing the lights from blending into a shapeless glow.

To ensure you don’t blur star trails, you can use either :

– the 500 rule to work out what shutter speed. The 500 rule works by dividing 500 by your focal length (ie 15mm lens), so 500/15 = 33.33. This means when using a 15mm lens on a full-frame camera, you can use a shutter speed of 33 seconds before getting blurry stars.

or

– You can use the PhotoPills Spot Stars pill to avoid star trailing. For calculating the necessary exposure time, use the PhotoPills Spot Stars calculator by following these steps:

• Open the PhotoPills app and navigate to the Spot Stars calculator.
• Enter your camera model, the lens focal length, the aperture setting, the minimum declination of the stars you’re capturing, and select the accuracy mode (with the default usually being sufficient).

If you’re unsure of the stars’ minimum declination, use the AR feature in PhotoPills. Point your phone in the direction you’re planning to shoot, and let the app calculate the exposure time for you. If in doubt, you can default the declination to 0º. PhotoPills > Spot Stars > AR. Tap the AR button, point your smartphone where you’re framing the camera and read the maximum exposure time you need to use.

7. ISO: 1600 to 8000. Start with ISO 2000-3200 as a baseline. Increase for weaker auroras or decrease for stronger ones. Here’s a detailed look at how to effectively use this ISO range:

1. Enhanced lightness. A high ISO allows a good lightness from a small exposure, which is crucial in dark environments where the aurora is visible. This allows you to capture the faint colors and details of the aurora that might not be visible at lower ISOs.

2. Faster shutter speeds. Using a higher ISO you can set faster shutter speeds. This is beneficial for capturing the dynamic, fast-moving shapes of the aurora with less blur, preserving the details and structures of the lights.

3. Compensate for dim conditions. In situations where the aurora is faint or you’re shooting in particularly dark locations without much ambient light, raising the ISO helps you achieve a balanced lightness without overly a long exposure that can lead to motion blur from the moving lights.

Before your aurora shooting session, test your camera’s performance at ISO 3200 to 8000 in low light conditions to understand its limitations and optimal settings.

While starting in the 3200 to 8000 range is a good baseline, constantly monitor your results and adjust as necessary:

• If the aurora becomes brighter, you might lower the ISO to reduce noise.
• Conversely, if the aurora is faint or you’re aiming to freeze its motion more sharply, you may need to push the ISO higher.

8. White Balance: Daylight or 4100-4300K. Dont use auto! I often use Daylight and adjust the colour temperature in post production. But Fluorescent (around 4100-4300K) can help maintain the natural colors of the aurora.

9. Shutter delay: 2s (optional). You’ll avoid any possible vibrations when you press the shutter button. This is only necessary if you won’t be using an intervalometer.

For very clear photos, make sure your camera is on a firm tripod. Use a 2-second timer to stop blur when you click the button. If it’s windy, use a 5-second timer instead to keep the camera still when you press the button.

You can also use an intervalometer. But when taking pictures of the northern lights and moving around to follow them, it’s easier to just use the camera’s timer.

10. Keep your batteries warm

Remember, the goal is to maximize your time under the aurora borealis.

Unfortunately, the cold, enchanting nights under the aurora can be harsh on your camera’s batteries…

Cold temperatures reduce battery life, often at the most unexpected moments during your shoot. To prevent this, an essential strategy is to keep your batteries warm, ensuring they retain their charge for as long as possible.

Always carry spare batteries and store them in a place where they can benefit from your body heat. A practical method is to keep them in a zip-lock bag tucked inside an inner pocket of your jacket, close to your body. This warmth can significantly slow down the rate at which your batteries deplete.

11. Fight condensation

One of the trickier aspects of southern lights photography is managing the transition between the biting cold outdoors and the warm indoors without causing condensation on your camera. This phenomenon not only obscures your lens but can also seep into your camera and lens, potentially damaging the internal mechanisms over time.

The key to preventing this is to control the temperature change your equipment experiences. Looking at weather reports especially establishing fog / dew point can help. You may need a special astro dew heater (this is a heated neoprene strap that wraps around your front lens element, and runs off a portable battery).

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How to Photograph the Southern Lights with your iPhone

You’re probably wondering if you can take aurora photos with your iPhone. Well, the short answer is… yes!

However, in order to shoot the southern lights you would need any iPhone model starting with iPhone 11. That’s because Night mode is only available on iPhone 11 and above models.

In low-light conditions Night Mode will automatically turn on. The Night Mode icon will appear in the top left corner of your phone. This feature keeps the camera sensor open for a longer amount of time in order to get more light in, and therefore capture more detail in the image.Oh. It’s super easy.

1. Open the camera app on your iPhone.
2. Your iPhones will automatically switch to Night Mode when it detects low light in the scene. If it doesn’t, set the camera app to Night Mode.
3. By default, depending on how dark the environment is, the exposure in iPhone’s Night Mode is somewhere between 1 and 3 seconds. If you need more than that you can change the exposure time to the maximum possible.
4. There’s a hidden settings menu in the iPhone’s camera app. Open this menu using the top arrow.
5. Look for the Night mode icon and tap on it.
6. A slider will appear that allows you to adjust the exposure time.
7. Slide it all the way to the right at Max.
8. Point the phone where you want to take your aurora photo.
9. Hold the phone with both hands and tap the shutter button.
10. Stand still until the iPhone has finished capturing the photo.

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Creating Aurora Panoramas

Creating a panoramic image of the southern lights involves stitching together multiple photographs to form a single, wide-view picture. This technique allows you to capture the vastness of the aurora australis and the surrounding landscape in great detail.

Here’s a step-by-step guide to creating a panoramic image of the Aurora

1. Equipment that you need

• Camera: Any camera that allows manual control of settings.
• Lens: A wide-angle lens is preferred for its broader field of view.
• Tripod: Essential for keeping your camera stable and aligned during the shoot.
• Panoramic head (optional): For precise alignment and rotation. Though not mandatory, it helps in matching the nodal point of the lens, reducing parallax errors.

2. Camera settings

• Set your camera to Manual mode (M) to have a consistent lightness across all shots.
• Set your lens to manual focus and adjust it to infinity or to the hyperfocal distance to ensure the stars and aurora are sharp.
• ISO, aperture, and shutter speed should be set according to the intensity of the aurora and the desired lightness

3. Composition and framing

• Plan your panorama: Visualize or sketch the entire scene you intend to capture, identifying key elements you want to include.
• Start from one end of the scene and decide on the overlap between images. A 30-50% overlap between consecutive shots is ideal for effective stitching.

4. Shooting the panorama

• Shoot in a consistent direction. Choose either left-to-right or right-to-left and stick with it.
• Keep the camera level to avoid uneven horizons. A tripod with a built-in level or a hot shoe bubble level can assist with this.
• Take multiple series if you’re unsure about the overlap or lightness. It’s better to have more images than you need than to miss a part of the panorama.

5. Post-processing

• Import your images into a photo editing software that supports panorama stitching (Lightroom, Photoshop, or a dedicated panorama software like PTGui).
• Select the images for your panorama and use the software’s “Merge/stitch to Panorama” function. Adjust settings according to the software’s options to blend the images seamlessly.
• Fine-tune the panorama: Adjust exposure, color balance, and crop the image as needed to create a cohesive final image.

Additional tips

• Practice shooting panoramas during the day to get comfortable with the process and your equipment.
• Consider the movement of the aurora. Fast-moving auroras may require quicker shooting between frames to maintain continuity in the panorama.
• Experiment with vertical panoramas (portrait orientation) for a different perspective, especially when the aurora is directly overhead.

Credit https://www.photopills.com/articles/northern-lights-photography-guide

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https://aurora-alerts.uk/

Space Weather Live  uses a very simple color code:

• Green: Low aurora activity.
• Yellow: Medium aurora activity.
• Red: The redder the plots get, the better is for aurora activity!

There are also several Facebook pages dedicated to sharing photos and receiving alerts.

https://www.facebook.com/groups/NZaurora

https://www.facebook.com/groups/SouthernHemisphereAuroraGroup

https://www.facebook.com/groups/shagupyaarse

(despite the name, this is legit!!)

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Using Space Weather Live to find out the Aurora Forecast

How do you actually know when you’re going to get an Aurora and of how to read the different indicators?

Open the app up.

The first thing you see on the homepage is the Kp index, which is basically a measure of

• The size of the auroral oval.
• The strength of the solar storm.

It’s a 3-hour average and it’s a global average. So Kp is an interesting indicator, because it’s just an average of whats happened.

So it’s a very basic indicator. It doesn’t tell you about little sub storms that happen which could be stronger.

Space Weather Live – The home screen shows you the current Kp index.

For here, you should have a look at a long term forecast. And that one will show you kind of maybe what’s expected over the next month.

To check it, tap More data > Aurora forecast.

Then, scroll down to the Long term Kp forecast chart.

However, take it with a grain of salt, because what the experts are basing that on is if you have an area of really high activity, like a coronal hole.

Coronal holes are the source of high speed solar wind streams. When these high speed streams arrive at Earth, they can produce active auroras.

The interesting thing is that a coronal hole can make more than one rotation. So as the sun rotates, you might see that again and again.

Now, go back to the homepage.

There, again, you can see the short term expected forecast for the next 3 days.

The app gives you a projected Kp forecast for a minimum and a maximum. And it also breaks it down into higher latitudes and mid latitudes.

And while the Kp index gives you a quick indication of the strongest observed geomagnetic activity over a 3-hour period, the real time solar wind indicators is the really helpful bit.

Real time solar wind speed

The origin of Southern lights is basically gusts of solar wind.

Therefore, the solar wind is the first piece of the puzzle that you need to know about to predict whether there will be aurora activity or not at a certain date and time of the day.

In this sense, Space Weather Live has a solar wind chart indicating the speed. The higher the speed, the higher chances of having aurora activity. The target is a speed 400 km/sec+, 500+ even better.

But to make things easier, you don’t need to remember any numbers or ranges. Just look at the color!

Quick recap of Space Weather Live’s color code:

• Green: Low aurora activity.
• Yellow: Medium aurora activity.
• Red: The redder the plots get, the better is for aurora activity!

Real time solar wind density

The second piece of the puzzle you need to know about is the density of the solar wind.

The density of the solar wind is basically the number of solar wind particles per square centimeter.

But in terms of aurora activity, which is what matters to you, the higher the solar wind density, the higher the aurora activity. The target is a density 10 p/cm3 +.

Again, when looking at the Space Weather app, look at the color code 😉

Space Weather Live – Keep scrolling down the home screen to see the interplanetary magnetic field variables.

Real time interplanetary magnetic field – Bt & Bz

The third & fourth piece of the puzzle you need to know about is the magnetic field of the Sun, also called interplanetary magnetic field (IMF).

OK, here’s a simple explanation. Charged particles can hold both an electric current and create a magnetic field. So as you can imagine, the charged particles given off by the Sun also hold a magnetic field. The particles stretch the magnetic field of the Sun around the planets. And this is what astronomers call the interplanetary magnetic field (IMF). The IMF value is a combined measure of the magnetic field strength in the north-south, east-west, and towards-Sun vs. away-from-Sun directions.

The see the best possible auroras you want that:

• The total strength of the interplanetary magnetic field (indicated with Bt) to be as high as possible (10+) and,
• The Z-component (Bz) of the interplanetary magnetic field towards the south. The stronger the negative value nT value to the south, the better. If it doesnt indicate south, I probably wouldn’t bother even going out myself if indicating north.

In other words

• Look for a high as possible Bt number.
• The longer the Bz stays south, the better.

These are 2 key indicators for me, as to whether or not I should go out and shoot.

Then check the auroral oval position and size

Don’t forget that the auroral oval is not a concentric circle – it’s pulled and twisted by our magnetic field lines.

So it actually moves around the Poles throughout time. And its size changes as well.

At Space Weather Live, you can have a look at NOAA ‘s auroral oval model. It gives you a short-term forecast of the intensity of the auroral oval for both the northern and the southern hemisphere.

So if a solar storm grows in intensity, that oval will actually get bigger and bigger.

From there you can set an alert on My Aurora Forecast

My Aurora Forecast – Tap the settings icon (gear) to adjust the notifications.

Then, select one of the models to access the forecast charts for temperature, humidity, and most importantly, precipitation and clouds.

In addition, I would also take note of the Hemispheric power, measured in GW. Again, this tends to be colour coded as a guide for how serious things will get!

Another worthwhile check at this stage, would also be on a local K index. Essentially to see if there may be an imminent upswing of magnetometer activity known informally as the ‘Cloake Effect’.

It has been observed quite frequently, that as magnetic levels start to turn upwards after a sudden dip, that visible auroral activity noticably increases also. Again one of those things that is not fully understood, but first observed by Timaru photographer Geoff Cloake, and subsequently supported by the amateur observer community.

https://www.swpc.noaa.gov/products/goes-magnetometer

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Another really confusing thing to get your head around, is the time used in many forecasts.

Usually these are given in UTC, which NZ is 12 hrs ahead normally, +13hrs during daylight saving.

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In summary, here are the weather and aural forecast key indicators to bear in mind:

• • Number of night hours. To capture auroras, you need a dark sky. This indicator tells you how long you can be shooting.
  • Moon phase. The less light in the scene, the brighter you’ll see the northern lights. So shoot on a night around New Moon. If you want some Moonlight to illuminate the scene and your foreground, try to shoot with some Moon or even a Full Moon.
  • Kp index. The higher the Kp index, the stronger the geomagnetic event (that is, the probability of having auroras). As noted previously, an adequate ‘broad’ tool.
  • Solar wind speed. The start of more in depth analysis of data. Again, the higher the solar wind density, the higher the aurora activity. Aim 400+
  • Solar wind density. Same thing here. The higher the solar wind density, the higher the aurora activity. Aim 10+
  • Interplanetary magnetic field (Bt and Bz). You need both of these to be true:
    • The total strength of the interplanetary magnetic field (indicated with Bt) to be as high as possible. Look for a high as possible Bt number.
    • The Z-component (Bz) of the interplanetary magnetic field towards the south. The longer the Bz stays south, the better.
  • Auroral oval. The bigger and brighter, the better.
  • Weather forecast (precipitation and clouds). You need clear skies!
  • Hemispheric Power
  • Cloake Effect
  • Time Difference / Forecast conversion

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Credit here must go to Photo Pils for the bones of this post.

7 Key Factors Determining if You Can See the Southern Lights

Actually, the Southern lights actually occur all year long, and all day long. Yet we can only get to experience them when certain conditions all come together. These things are:

• The time of the day. It must be dark!
• Your location. Both in terms of actual latitude, as well as a location free from light pollution.
• The time of the year.
• The moon phase.
• Terrestrial (earth / land) weather.
• The solar weather / activity.
• Solar Cycle

1) Time of Day

Let’s break these down. You can see auroras at any time of the day as long as it is dark, there are clear skies, and solar activity.

However,

• The strongest lights tend to appear between 21:00 and 2:00, though the best sightings often occur between 23:00 and midnight. That’s because, even after the sun goes down, there’s still a little bit of light left in the sky for a while.
• Between 04:00 and 17:00 there is generally too much daylight to see the aurora.
• Exceptions are the darkest months of the year and higher latitudes, where it is dark 24/7. In the Southern hemisphere this tends to be from mid-May to the end of July.

2) Location

In the northern hemisphere, the aurora is often more pronounced because you can access land mass within the aurora oval (between 60º and 75º S)

To photograph auroras in the southern hemisphere, we have a lot of ocean at this latitudes so are forced to settle with a vantage point closer to the equator than places like Norway, Iceland, & Canada provide. So unless you get to go to Antarctica, you’ll need to go beyond the aurora oval.

In addition to this, you need to find a location with little or no pollution at all.

• In the middle latitudes (above 67ºS), such as the south of Western Australia, Tasmania and New Zealand, the direction to point your camera to is paramount. Look for unobstructed views facing south.
• Closer to the pole (between 67ºS and 90ºS), in Antarctica, the aurora can happen pretty much anywhere in the sky. Contrary to the northern hemisphere, the lights often start to show up from west to east. But as the night goes on, they can occur in any direction.

Illustration by William Copeland. What are the northern lights? Sept. 2020.
URL: https://nordnorge.com/en/artikkel/what-are-the-northern-lights/.

3) Time of Year

Regardless of the hemisphere you plan to travel to, spring and autumn generally provide more stable weather conditions and milder temperatures plus there is greater aurora activity around the equinoxes.

That is…

• The second and third week of March.
• The last two weeks of September.

Southern hemisphere

To see the aurora australis the best time is during the autumn and winter, from March to September. That’s when the nights are really long and super dark. During these months, the nights are really long and dark, which makes it easier to see the beautiful lights dancing in the sky. Even though these lights are always there, you can’t see them in the summer months like Nov, Dec, Jan, Feb because the sun is too bright and hides them.

4) Moon Phase

Scientifically speaking, the moon doesn’t make the northern lights stronger or weaker. In other words, you can actually photograph auroras in any moon phase.

Having said that, the moon can affect how much light there’s in the scene and, thus, how you see (and your camera captures) the aurora in the sky, the stars and the foreground:

Around New Moon or with no Moon at all (after Moonset)

When there’s a New Moon or no moon at all (you’re shooting after Moonset) it’s really dark.

In these conditions, a strong solar activity will create bright northern lights. On the other hand, a faint aurora may be difficult to see even if there is no moon visible.

When the scene is really dark your foreground will be quite dark too. So take this into account when creating your composition.

With Moon (phase less than 50%)

A bright moon may wash away the details of a faint aurora and stars, but you can still see the aurora easily.

Since the Aurora is dependent on solar activity and shifting weather patterns, a moon with a phase less than 50% has no effect on the intensity or color of the northern lights.

Depending on the Moonlight conditions, you may have enough light to capture detail in the foreground.

Around Full Moon

When the moon is full and bright, it’s like having a big flashlight in the sky, which can make the northern lights look less bright.

But seeing the big, bright moon and the northern lights together can be really cool, like a special light show. The contrast is not as great but it tends to make the sky appear a dark indigo blue.

If you’re taking pictures, the moon an help by lighting up things on the foreground, making your photos look nicer because you can include part of the landscape in your composition.

5) Terrestrial (earth / land) Weather

It’s important that the sky is clear and doesn’t have clouds covering it up!

How can you check weather

You can download the Windy application on your smartphone and tablet. You can also go to the website on your laptop and desktop computer.

Windy is available on iOS and Android.

6) Solar Weather

Usually there needs to some elevated space weather by way of CME, flare or coronal hole.

What solar activity is best for southern lights?

The brightness of the aurora is determined by the amount of solar activity in the location.

The solar activity is measured with the Kp index, the solar wind speed and intensity, and the interplanetary magnetic field strength and direction.

Even though I have posted about the limitations of Kp (being past activity and driven by Northern hemisphere magnometers), it does give us a starting point. For now, let’s use the Kp index.

The Kp index is based on how the solar wind and Earth’s magnetic field are interacting at the moment.

It helps you guess where and how well you’ll see the northern lights. In other words, it’s like a weather forecast but for the northern / southern lights.

It measures how much the solar wind is shaking Earth’s magnetic field, on a scale from 0 to 9. A low number means not much is happening, but a high number means a big light show might be coming.

• 0 to 4: The northern lights might be quiet and faint, mostly green, and you might need a camera to really see them well.
• 5 to 6: Things get exciting! The lights move more and might show off colors like yellow, pink, or even purple. If you’re lucky, you might see a special kind of northern light called a corona, where the lights swirl directly overhead.
• 7 to 9: This is when the northern lights go all out. They can fill the sky, show rare colors like red, and be seen much further south than usual.

In places like Alaska, Canada or Iceland, a Kp 3 means a good chance of seeing the lights. But to see them in places further south, like NZ, you’d need a Kp 5 or more.

A Kp 5 or more means a solar storm of grade G1 is happening. The higher the Kp number, the stronger the storm. A Kp 9 is a very big deal and means the maximum possible storm (grade G5) is happening.

Nevertheless, the Kp-index gives you an idea of what the auroras might do, but it’s not perfect. It’s always a bit of a guess, so it’s good to check the forecast and hope for clear skies.

We will look into this some next post, with further detail just how you can gauge all this.

7) Solar Cycle

The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun‘s activity measured in terms of variations in the number of observed sunspots on the Sun’s surface. Over the period of a solar cycle, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation from a period of minimum activity to a period of a maximum activity back to a period of minimum activity.

The magnetic field of the Sun flips during each solar cycle, with the flip occurring when the solar cycle is near its maximum. After two solar cycles, the Sun’s magnetic field returns to its original state, completing what is known as a Hale cycle.

This cycle has been observed for centuries by changes in the Sun’s appearance and by terrestrial phenomena such as aurora but was not clearly identified until 1843. Solar activity, driven by both the solar cycle and transient aperiodic processes, governs the environment of interplanetary space by creating space weather and impacting space- and ground-based technologies as well as the Earth’s atmosphere and also possibly climate fluctuations on scales of centuries and longer.

We are currently in cycle 25, which started Dec 2019.

Types of Auroral Observations

Credit : Ian Cooper, Astronomer, Aurora Australis NZ Facebook page.

Airglow

On the back of all this, it is probably worth a quick mention about a non Auroral phenomenon, called airglow. Whereas an aurora is driven by high-energy particles originating from the solar wind, airglow is energized by ordinary, day-to-day solar radiation. Airglow is faint luminescence of earth’s upper atmosphere that is caused by air molecules’ and atoms’ selective absorption of solar ulttraviolet and X-radiation. Unlike auroras, which are episodic and fleeting, airglow constantly shines throughout Earth’s atmosphere, and the result is a tenuous bubble of light that closely encases our entire planet. (Auroras, on the other hand, are usually constrained to Earth’s poles.) Just a tenth as bright as all the stars in the night sky, airglow is far more subdued than auroras, too dim to observe easily except in orbit or on the ground with clear, dark skies or a sensitive camera. But it’s a marker nevertheless of the dynamic region where Earth meets space.

Most of the airglow emanates from the region about 50 to 300 km (31 to 180 miles) above the surface of Earth, with the brightest area concentrated at altitudes around 97 km (60 miles). Unlike aurora, airglow does not exhibit structures such as arcs and is emitted from the entire sky at all latitudes at all times. The nocturnal phenomenon is called nightglow. Dayglow and twilight glow are related terms. Nightglow is very feeble in the visible region of the spectrum; the illumination it gives to a horizontal surface at the ground is only about the same as that from a candle at a height of 91 metres (300 feet). It is possibly about 1,000 times stronger in the infrared region.

This photochemical luminescence (which is also called chemiluminescence) is caused by the chemical reactions of incoming solar radiation with atoms and molecules present in the upper atmosphere. Sunlight supplies the energy needed to raise these materials to excited states, and they in turn produce emissions at particular wavelengths. Atmospheric scientists frequently observe emissions from Sodium (Na), hydroxyl radical (OH), molecular oxygen (O₂), and atomic oxygen (O). Emissions of sodium occur in the sodium layer (some 50 to 65 km [31 to 40 miles] above Earth’s surface), whereas emissions from OH, molecular oxygen, and atomic oxygen are most concentrated at altitudes of 87 km, 95 km, and 90–100 km, respectively.

Observations from Earth’s surface and data from spacecraft and satellites indicate that much of the energy emitted during nightglow comes from recombination processes. In one such process, radiant energy is released when oxygen atoms recombine to form molecular oxygen, O₂, which had originally become dissociated upon absorbing sunlight. In another process, free electrons and ions (notably ionized atomic oxygen) recombine and emit light.

In the daytime and during twilight, the process of  resonance scattering of sunlight by sodium, atomic oxygen, nitrogen, and nitric oxide seems to contribute to airglow. Moreover, interactions between cosmic rays from deep space and neutral atoms and molecules of the upper atmosphere may play a role in both the nocturnal and daytime phenomena in the high latitudes.

So sometimes when out taking photos, it looks like you might have an aurora, despite no space weather indicating an auroral event. When that is the case, it is most probable you have captured airglow instead.

Credit : https://www.britannica.com/science/airglow

Additional credit : https://en.wikipedia.org/wiki/Solar_cycle

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2) Measuring Solar Flare Intensity: GOES (Geostationary Operational Environmental Satellite) X-ray Detector

https://www.swpc.noaa.gov/products/goes-x-ray-flux

It is also possible to view a graph of x-ray radiation intensity at the suns surface recorded by (currently) the GOES 15 satellite. This provides a time-line of solar flare activity, updated in real time. Solar flares can be classified by intensity. C-Class flares are weak, M-Class flares are moderate, and X-class flares are of extreme intensity. Here’s an example of two X-class flares over a period of just three days back in July 2000:

5) Observing the effect at Earth – Magnetometers

https://www.swpc.noaa.gov/products/goes-magnetometer

https://www.sws.bom.gov.au/World_Data_Centre/1/2

http://www.irf.se/Observatory/?link[Magnetometers]=Data/

Finally we have the effect of the impacting solar wind on Earth’s magnetic field. When the disturbance finally arrives there can be quite a shake-up of the Earth’s own magnetic field, and this geomagnetic disturbance can be measured on a device called a magnetometer. Magnetometers measure variations in the intensity and direction of the local magnetic field, a sort of “seismograph” for geomagnetic disturbances.

2) NOAA Ovation Aurora Forecast Model

https://www.swpc.noaa.gov/products/aurora-30-minute-forecast

This map attempts to take all the raw data available and then plots the probability and predicted location of the aurora from that data. The map is reasonably self explanatory. As the red “view line” gets closer to your location, the greater the chance of you seeing something. It’s worth noting however a number of brief auroral outbursts have been viewed when the view line was still plotted further south.

3) GOES-16 (Geostationary Satellite) Magnetometer Tracings and Prediction of Substorms (The “Cloake Effect”)

https://www.swpc.noaa.gov/products/goes-magnetometer

Long time aurora observer and Timaru based photographer Geoff Cloake was first to note an apparent pattern of auroral rays briefly appearing in association with sudden upswings in the GOES magnetometer tracing (the blue line in the tracing below). This effect has subsequently been observed on numerous occasions, and has proven extremely useful in helping some diehard observers to position themselves in a dark location just as a brief auroral substorm makes an appearance.

Credit : 

Dr Stephen Voss, ‘Aurora- The Jargon Explained’, March 2015 v3

Summary

If activity using the k / kP index shows a heightened reading, there are additional graphs, observations and data that can be used to provide greater analysis, that we can use to anticipate any incoming space weather. Subsequently, any upcoming auroral possibility still to eventuate.

These additional graphs, data, observations and readings are much better indicators of the likelihood of seeing (or photographing) auroral activity, as this data comes further out from various satellite & solar monitoring sources. So can give us some forewarning ranging from minutes to days. I’ll explain some of these in the next posts.