Space weather looking good for space exploration

October 7th, 2019, Published in Articles: EngineerIT, Featured: EngineerIT

While NASA is delighted that the next solar cycle is predicted to be the weakest in 200 years, many others who rely on the ionosphere to produce high frequency propagation (HF) will be less enthusiastic, while satellite owners will also be delighted with a lower possible solar impact on their operations.

The last astronauts of the Apollo programme were lucky, they missed some really bad weather en route. This wasn’t a hurricane or heat wave, but space weather – the term for radiation in the solar system, much of which is released by the sun.

In August 1972, right in between the Apollo 16 and Apollo 17 missions, a solar storm occurred sending out dangerous bursts of radiation. On Earth, we’re protected by the magnetic field, but out in space, this would have been hazardous for the astronauts.

The ability to forecast these kinds of events is increasingly important as NASA prepares to send the first woman and the next man to the moon under the Artemis programme. Research now underway may have found a reliable new method to predict this solar activity. The sun’s activity rises and falls in an eleven-year cycle. The forecast for the next solar cycle says it will be the weakest of the last 200 years. The maximum of this next cycle, measured in terms of sunspot number, a standard measure of solar activity level, could be 30 – 50% lower than the most recent one. The results show that the next cycle will start in 2020 and reach its maximum in 2025.

Fig. 1: On 31 August 2012, a long filament of solar material that had been hovering in the sun’s atmosphere, the corona, erupted out into space. This coronal mass ejection — an immense cloud of magnetised particles — travelled at over 1400 km/h. The ability to forecast these kinds of events on the sun is increasingly important as NASA prepares to send humans to the moon under the Artemis programme. [NASA’s Goddard Space Flight Centre].

Sunspots are regions on the Sun with magnetic fields thousands of times stronger than the earth’s. Fewer of them at the point of maximum solar activity means fewer dangerous blasts of radiation.

Both the forecast and the improving ability to make such predictions about space weather are good news for mission planners who can schedule human exploration missions during periods of lower radiation, when possible.

The new research was led by Irina Kitiashvili, a researcher with the Bay Area Environmental Research Institute at NASA’s Ames Research Centre, in California’s Silicon Valley. Observations from two NASA space missions were combined, the Solar and Heliospheric Observatory and the Solar Dynamics Observatory with data collected since 1976 from the ground-based National Solar Observatory.

One challenge for researchers working to predict the sun’s activities is that scientists don’t yet completely understand the inner workings of the sun. Plus, some factors that play out deep inside the sun cannot be measured directly. They must be estimated from measurements of related phenomena on the solar surface, like sunspots.

Kitiashvili’s method differs from other prediction tools in terms of the raw material for its forecast. Previously, researchers used the number of sunspots to represent indirectly the activity of the solar magnetic field. The new approach takes advantage of direct observations of magnetic fields emerging on the surface of the sun, data which has only existed for the last four solar cycles.

Mathematically combining the data from the three sources of sun observations with the estimates of its interior activity generated a forecast designed to be more reliable than using any of those sources alone.

In 2008, the researchers used this method to make their prediction, which was then put to the test as the current solar cycle unfolded over the past decade. It has performed well, with the forecast strength and timing of the solar maximum aligning closely with reality.

New research points to plasma tsunamis to trigger a new solar cycle

New research carried out by scientist, Scott W. McIntosh, Robert J. Leamon, Ricky Egeland, Mausumi Dikpati, Yuhong Fan, and Matthias Rempel at the US National Centre for Atmospheric Research (NCAR) has shown more light on the ability to forecast when one solar cycle ends and a new one starts. In two scientific papers, scientists painted a picture of how solar cycles suddenly die, potentially causing tsunamis of plasma to race through the sun’s interior and triggering the birth of the next sunspot cycle a few weeks later.

While the scientific community has known that solar cycles last approximately eleven years, predicting when a cycle ends and the next cycle starts has been challenging to pin down with any accuracy. They believe that with their new research, this could change.

In one of the studies, which relies on nearly 140 years of solar observations from the ground and space, the scientists can identify “terminator” events that clearly mark the end of a sunspot cycle. With an understanding of what to look for in the run up to these terminators, it is predicted that the current solar cycle (Solar Cycle 24) will end in the first half of 2020, kicking off the growth of Solar Cycle 25 very shortly thereafter.

In a second study, scientists explored the mechanism for how a terminator event could trigger the start of a new sunspot cycle using a sophisticated computer model. The resulting simulations show that “solar tsunamis” could provide the connection and explain the sun’s remarkably rapid transition from one cycle to the next.

“The evidence for terminators has been hidden in the observational record for more than a century, but until now, scientist didn’t know what they were looking for. By combining such a wide variety of observations over so many years, it was possible to piece together these events and provide an entirely new look at how the sun’s interior drives the solar cycle.”

Fig. 2: The computer model simulation shows a solar tsunami which is initiated at the sun’s equator. As the tsunami travels towards the poles, it floats the toroidal magnetic field (white lines) travelling deeper in the solar interior. As these bands are lifted to the surface, they erupt as sunspots on the solar surface [Visualisation by Mausumi Dikpati NCAR].

“In the next year, we should have a unique opportunity to extensively observe a terminator event as it unfolds and then to watch the launch of Sunspot Cycle 25,” McIntosh said. “We believe the results, especially if the terminator arrives when predicted, could revolutionise our understanding of the solar interior and the processes that create sunspots and shape the sunspot cycle.”

If you are planning a trip to the moon, 2024 seems a good time to heed US president Donald Trump’s call to travel to the moon on a NSA mission and stay there? But according to Trump it is only first for women.

Send your comments to engineerit@ee.co.za

Related Articles

  • DC-DC converter market forecast to 2026
  • How to choose the right cloud provider
  • South Africa’s communication landscape is a mixed grill
  • Industrial robots for flexible manufacturing needs
  • Simplifying power efficiency testing