Our Friend the Sun

I had the opportunity to listen to a leading Space Weather Expert the other day, a chat with Professor Gordon P Turnbull. While the questions he was asked may seem a little basic I thought it worth reprinting the transcript here:

Can you explain sunspots?

Sunspots are dark spots on the surface of the sun that are cooler and less active than the surrounding areas. They are caused by intense magnetic activity and are associated with solar flares and coronal mass ejections. Sunspots can last for a few days to a few months and their number and size varies over time in a pattern known as the sunspot cycle. The sunspot cycle is roughly 11 years long and during the maximum phase of the cycle, there are more sunspots and more solar activity. Sunspots have been observed and studied for centuries and have been found to have a significant impact on Earth's climate and weather.

What effect do sunspots have on the earth’s ionosphere?

Sunspots can have a significant impact on the Earth's ionosphere, which is the layer of the Earth's atmosphere that is ionized by solar radiation. The ionosphere plays an important role in long-distance radio communication and navigation.

During times of high solar activity, such as during the maximum phase of the sunspot cycle, the ionosphere can become more active and dynamic. This can result in increased ionization and a thicker ionosphere, which can lead to improved radio propagation and increased absorption of radio waves. This can cause changes in the frequency of the radio waves, which can cause distortion and fading of long-distance radio signals. This can be particularly problematic for high-frequency (HF) radio communications.

On the other hand, during times of low solar activity, such as during the minimum phase of the sunspot cycle, the ionosphere can become less active and stable. This can result in decreased ionization and a thinner ionosphere, which can lead to poor radio propagation and increased scattering of radio waves. This can cause increased noise and fading of long-distance radio signals. This can also be particularly problematic for high-frequency (HF) radio communications.

Overall, sunspots can have a significant impact on the Earth's ionosphere and can affect long-distance radio communication and navigation.

Thanks. Can you explain the K and A indexes?

The K and A indices are measures of geomagnetic activity. They are used to quantify the level of disturbance in the Earth's magnetic field caused by solar activity.

The K index is a measure of the short-term variation in the Earth's magnetic field and is based on data from a single magnetic observatory. It is a 3-hourly measurement and ranges from 0 to 9, with higher values indicating greater geomagnetic activity. The K index is based on the deviation

of the Earth's magnetic field from a quiet-day curve and is calculated using the largest deviation in each of the three magnetic field components (H, D and Z) over a 3-hour period.

The A index is a measure of the longer-term variation in the Earth's magnetic field and is based on data from multiple magnetic observatories. It is a daily measurement and ranges from 0 to 400, with higher values indicating greater geomagnetic activity. The A index is based on the average of the K index values over a 3-hour period and is calculated for each of the magnetic field components (H, D and Z) and then combined to give a single value.

Both the K and A indices are used to indicate the level of geomagnetic activity and are used in forecasting and in the study of space weather. They are also used to help operators of power systems, pipelines, and communication systems to protect their equipment and networks from the effects of space weather.

K and A indices are both published by various space weather agencies and can be accessed online, including the National Oceanic and Atmospheric Administration (NOAA) in the United States and the European Space Weather Portal (ESWP) in Europe.

Brilliant. What are solar storms then?

Solar storms, also known as space weather events, are disturbances in the solar wind that can affect the Earth's magnetic field, atmosphere, and climate. They are caused by the sun's activity, such as solar flares and coronal mass ejections (CMEs), which send large amounts of charged particles and electromagnetic radiation towards the Earth.

Solar flares are sudden, intense bursts of electromagnetic radiation that are emitted from the sun's surface. They are caused by the sudden release of magnetic energy stored in the sun's atmosphere.

Coronal mass ejections (CMEs) are large eruptions of plasma and magnetic field from the sun's corona, which is the outermost layer of the sun's atmosphere. They are caused by the sudden and explosive release of magnetic energy stored in the sun's corona.

Both solar flares and CMEs can cause disturbances in the solar wind, which is a stream of charged particles that flow out from the sun in all directions. When these disturbances reach the Earth, they can cause geomagnetic storms, which are disturbances in the Earth's magnetic field.

These solar storms can have a range of effects on the Earth, including:

• Interference with satellite and communication systems

• Power grid disruptions

• auroras (northern and southern lights)

• Increased radiation levels for astronauts and high-altitude aircraft

• Disruption of GPS signals

• Damage to orbiting satellites

Overall, solar storms are disturbances in the solar wind caused by the sun's activity and can have a range of effects on the Earth's magnetic field, atmosphere, and climate.

Quite enlightening I’m sure you’ll agree. If you’ve stuck with reading this article to the end you might be wondering if Professor Turnbull really speaks like that? Well, he doesn’t. In fact, he doesn’t exist at all. The questions are my own and the answers are produced by ChatGPT, Gordon P Turnbull, get it? CHatGPT is an AI chatbot that uses an internet-scraped dataset to answer real-world questions conversationally. There has been no editing of the answers at all.

The data is a couple of years old so don’t ask about the war in Ukraine for example as it will probably describe the siege of Sevastopol in 1855, which we won.

ChatGPT is free to try with a trial account here https://chat.openai.com/

Microsoft is investing heavily in the firm behind this tech and there is a more capable and modern version in development now.

Unsurprisingly, many firms including HMG have banned the use of ChatGPT. It is after all that chatty equivalent of Wikipedia on steroids and everything on the internet is true, isn’t it?

73 Mike, G0KAD (or is it???)