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A conversation with NOAA space scientist Rob Steenburgh


April 7, 2023 -- Activity on the Sun is steadily increasing as we move deeper into Solar Cycle 25. In addition to more sunspots on the Sun, energetic events like solar flares and coronal mass ejections have become more frequent in the past year, and especially in the past month.

NOAA’s Space Weather Prediction Center (SPWC) issues warnings and alerts to help federal partners, public utilities, and business interests mitigate impacts of space weather. We connected with SWPC’s Rob Steenburgh to talk about space weather and what to expect during Solar Cycle 25’s solar maximum.

What is space weather and how does it affect Earth?

Space weather refers to variations in the space environment between the Sun and Earth (and throughout the solar system). Some space weather events, called coronal mass ejections”, start as eruptions from the sun’s surface. These events are common, occurring on average two times a day during the most active period of the 11-year solar cycle. The majority of these eruptions are not directed towards Earth. Those that are Earth-directed can produce colorful aurora, but can also disturb critical infrastructure on Earth.

Which space weather phenomena is most damaging?

For many, the greatest concern is geomagnetic storms driven by coronal mass ejections (CME). They can affect the electrical power grid. The strength and timing of the storm determines how big an effect it has. Because society depends heavily on electric power, this threat to grids is taken very seriously. SWPC works closely with the power industry, federal regulators, emergency managers, and others to help them prepare for geomagnetic storms so they can take action to minimize the impacts. Fortunately, the biggest storms are extremely rare.

High-frequency radio communication (3-30 MHz) can be affected by geomagnetic storms, too, as well as by solar flares and solar radiation storms. A disruption of radio communications can impact a variety of people and businesses, including airlines, disaster response agencies, and amateur radio operators.


Animated gif of a coronal mass ejection on the Sun
NOAA’s GOES East satellite captures a coronal mass ejection on the Sun, seen here in the NE quadrant, March 7, 2023. (Credit NOAA)
(Credit NOAA)

Space weather like radiation storms and ionospheric disturbances can also disrupt satellites' ability to operate and communicate. Increased orbital drag caused by space weather may reduce low-Earth orbit satellites' lifetimes or make a satellite inoperable. In February 2022, space weather is likely the cause of the loss of 38 Starlink satellites after launch.

Finally, astronauts in space can be impacted by space radiation events. This is especially true for astronauts if they’re outside the protective environment of their spacecraft, or outside of the protection of Earth’s magnetic field.

Should I worry about space weather?

No. Your likelihood of directly experiencing impacts from space weather, beyond seeing the aurora, is very low. However, if you like to prepare, please check out our tips.

Where can I find your space weather watches, warnings and alerts?

We post space weather forecast products on SWPC’s website. There, you also can learn about NOAA’s Space Weather Scales.

What is solar maximum and what can we expect?

Solar Cycle 25 began in December 2019 and it is predicted to reach solar maximum — the period when the Sun is most active — in mid 2024. A solar cycle runs 11 years. Solar Cycle 25 is outperforming the prediction, but is still considered average when compared to the past 24 cycles. Increased activity on the Sun means there may be more opportunities to see the aurora.

What tools do SWPC forecasters use to monitor and forecast space weather?

Space weather is generated by the Sun, and that’s where our analysis begins. We use satellites and ground-based telescopes to view activity at various depths in the solar atmosphere. NOAAs GOES-17 and GOES-18 satellites, provide beautiful images of the Sun from 22,000 miles from Earth. The satellites’ wide field of view is revealing aspects of the Sun previously unseen by operational spacecraft. This new data is unlocking new and exciting lines of research.

After focusing on the Sun, our analysis then moves out into interplanetary space.

NOAA’s Deep Space Climate Observatory, also known as the DSCOVR spacecraft, is situated about a million miles from Earth, between Earth and the Sun. It measures the solar wind which is essential for predicting the strength and time of geomagnetic storming on Earth. SWPC forecasters base some warnings on solar wind data we get from DSCOVR along with numerical model outputs and ground magnetometer observations. Solar wind data from DSCOVR is also an essential input to many numerical space weather prediction models.

Additionally, SWPC forecasters use the coronagraph aboard the Solar and Heliospheric Observatory (SOHO), which provides images of CMEs and allows us to characterize the eruption as it hurtles through space. These measurements are fed into a computer model that helps predict the timing of the geomagnetic storm.

SOHO is an old research spacecraft, launched in 1995. Plans are underway for NOAA to launch the Space Weather Follow-On L1 and replace SOHO and DSCOVR. The new spacecraft will carry an operational coronagraph, a significant step forward for space weather forecasting.

What computer models are used in space weather forecasting?

The number of computer models used by SWPC forecasters has exploded in the past decade. We now have 16 forecast models. I’m excited about two of our newest models. The Geoelectric-field model gives utility operators critical information about the impact of changes in the Earth’s magnetic field on the power grid. Similarly, the Whole Atmosphere Model - Ionosphere, Plasmasphere, Electrodynamics (WAM-IPE) model provides guidance to forecasters when issuing alerts for radio and GNSS disturbances. It is also used for orbit prediction and space traffic management.

You mentioned aurora. Does SWPC predict when and where I can see it?

Yes. SWPC’s 30 minute aurora forecast is probably our most popular model! We also estimate the potential extent of the aurora for tonight and tomorrow night on our experimental Aurora Dashboard. When a geomagnetic storm arrives, colorful lights in the sky can occur simultaneously around both the north (Aurora Borealis) and south (Aurora Australis) polar regions. Stronger geomagnetic storms push the aurora toward the equator, making it visible to a larger number of people.

How can I watch the Sun safely?

Never look directly at the Sun without protection. You can monitor the Sun safely with our space-based GOES Solar Ultraviolet Imager7, and from a network of ground based GONG (Global Oscillation Network Group) telescopes. Both platforms provide imagery in near-real time. In April 2024, we will be treated to a total solar eclipse and the opportunity to see the Sun’s corona during an active solar period. If you are lucky enough to be in the path of the solar eclipse, be sure you wear eclipse glasses to filter out harmful rays.

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Aurora in Fairbanks, Alaska, January 1, 2023
Aurora in Fairbanks, Alaska, January 1, 2023 (Credit NOAA)

For questions or comments on this story, please contact Maureen O’Leary, NWS Public Affairs,