MINOR SOLAR WIND STREAM: An equatorial hole in the sun's atmosphere is facing Earth, and it is spewing a minor stream of solar wind in our direction, Estimated time of arrival: Feb. 15-16. The gaseous material is not expected to cause a geomagnetic storm. Nevertheless, Arctic sky watchers can expect an uptick in polar auroras. Aurora alerts: SMS Text.
SURFING THE JET STREAM REDUCES AVIATION RADIATION: Climate change is revving up the jet stream. The river of air which meanders around the North Pole is quickening, propelling planes across the north Atlantic at record speed. Just this weekend, on Feb. 8th, British Airways Flight 112 rocketed from New York to London in 4 hours 56 minutes, at one point traveling faster than 825 mph.
Why do we care? Because airplanes surfing the jet stream absorb significantly less cosmic radiation.
(Top)The flight path of British Airways 112 and (Bottom) the transatlantic jet stream on Feb. 8, 2020. Credit: FlightRadar24.com
Researchers have long known that air travelers are exposed to cosmic rays. At typical cruising altitudes, passengers absorb 50 to 100 times more radiation than they would at sea level. This has led the International Commission on Radiological Protection (ICRP) to classify pilots and flight attendants as occupational radiation workers.
By shortening flights, the jet stream reduces exposure to cosmic rays. Passengers onboard the record-setting British Airways flight spent an hour less at cruising altitude and, according to our models, absorbed about 30% less radiation. Two Virgin Atlantic flights following close on the heels of the British Airways 747 had similar results.
These conclusions are based on E-RAD, a new model for aviation radiation. Since 2015, we (Spaceweather.com and the students of Earth to Sky Calculus) have been collecting X-ray, gamma-ray, and neutron radiation data onboard airplanes. Our database contains more than 25,000 radiation measurements over 27 countries, 5 continents, and 2 oceans. E-RAD uses these measurements to predict dose rates on flights in regions of the world we have visited, such as the north Atlantic.
We applied E-RAD to British Airways Flight 112 on several dates, comparing dosages on Feb. 8th, when the plane surfed the jet stream, to nearby dates when it didn’t. Surfing the jet stream shaved 6 to 10 uSv (microSeiverts) off the total radiation dose, a reduction equivalent to ~1 dental X-ray.
It’s not all good news, though. The jet stream can cause trouble. An active, fast-moving jet stream is often filled with turbulence, making flights miserable for passengers. Planes dodging the rough air can actually increase their flight times, boosting cosmic ray exposure instead of reducing it.
Oh, and did you want to go home? Passengers returning to New York from London have to cross the Atlantic against the jet stream. Their flights will be slower, increasing exposure-time. Indeed, we calculated the radiation exposure for British Airways Flight 117 on Feb 8th, which flew in the opposite direction, from London to New York. Passengers onboard that aircraft would have received double the dosage–34.4 uSv (London to New York) instead of 17.7 uSv (New York to London).
Climate change research suggests that all of these effects will intensify in the years ahead. A seminal study in 2016 found that, overall, changes in atmospheric dynamics would increase round-trip times between London and New York despite the quickening jet stream. In the end, it seems, you just can’t avoid "rads on a plane."
A sharable version of this story is available here.
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VALENTINE'S GIFTS FROM THE EDGE OF SPACE: Valentine's Day is less than a week away. Nothing says "I love you" like a gift from the edge of space. Everything in the Earth to Sky Store is 10% off from now until Feb. 14th:
Everything in the store has been flown to the stratosphere onboard cosmic ray balloons, which the students of Earth to Sky Calculus launch approximately once a week to monitor atmospheric radiation. All sales support our cosmic ray ballooning program and help launch young scientists into research careers through hands-on STEM education.
At checkout, be sure to enter the coupon code "ILOVESPACE"!
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All sales support hands-on STEM education
A METEOR STORM IN SPACE? Spoiler alert: It's not a meteor storm. Earlier today, coronagraphs onboard the Solar and Heliospheric Observatory (SOHO) were staring at the sun, waiting for the next coronal mass ejection, when a flurry of objects streaked across the field of view. This animation shows what happened:
The starry background was briefly overwhelmed by smears of light, as if a stream of debris had engulfed the spacecraft. In fact, the "meteor storm" may have come from the spacecraft itself.
Ever since SOHO was launched in 1995, coronagraph images have occasionally recorded streaks of light. Mission controllers believe they are bits of insulation flaking off the sun-facing side of the spacecraft, reflecting sunlight as they race out-of-focus in front of the coronagraph's digital camera.
Today's event was more dramatic than most. Indeed, a meteoroid might have been involved. A micrometeoroid strike might have dislodged a spray of insulation, resulting in not one but dozens of luminous streaks. Whatever happened, it didn't harm the spacecraft. SOHO is still operating normally.
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