An interesting research paper by
Communications Medicine finds that geomagnetic activity can spike blood pressure levels.
ION REGION: A co-rotating interaction region (
CIR) is expected to hit Earth on
Aug. 18th, squeezing our magnetic field between fast and slow streams of solar wind. Watch for a sudden jump in solar wind speed, density, and magnetic field (especially
Bz). Minor
G1-class geomagnetic storms and high-latitude auroras are possible if Bz turns south.
CIR impact alerts: SMS Text
Solar activity might be doing more than sparking auroras.
A new study in
Communications Medicine suggests it could be nudging your blood pressure, too.
Researchers in China analyzed more than half a million blood pressure readings taken over six years in the cities of Qingdao and Weihai. They compared those measurements to the
Ap index, a standard measure of geomagnetic activity. The result: Blood pressure rises and falls in rhythm with magnetic unrest.

A sample of the dataset showing the correlation between BP and Ap.
See Fig 1 for more.
Both systolic and diastolic blood pressure showed a bimodal pattern, with peaks in spring and autumn, mirroring the
seasonal ups and downs of geomagnetic activity. In years when geomagnetic activity was strong, blood pressure peaked about one month after the Ap index. During quieter years, the lag stretched to two months. The data revealed matching cycles at 12, 6, and sometimes 3 months -- present in the Ap index but absent from other environmental factors.
"We found that blood pressure and geomagnetic activity share distinct seasonal patterns," says Quanqi Shi, one of the paper's co-authors from Shandong University. "There seems to be a genuine link between the two."
Importantly, the study found no similar multi-month patterns in air temperature or PM2.5, two well-known influences on blood pressure. While temperature correlated more strongly with blood pressure in a straightforward statistical sense, its effect lacked the 6- and 3-monthcycles seen in geomagnetic data.

The authors stop short of saying that geomagnetic activity
causes high blood pressure. Their data cannot prove cause and effect. Still, Shi and his colleagues are exploring how such a link might work.
"One possible mechanism involves the modulation of ultra-low frequency waves, specifically
Schumann resonances (pictured right), which occur within Earth's magnetosphere. The fundamental frequency of Schumann resonances is approximately 7.8 Hz, with harmonics around 14.1, 20.3, 26.4, and 32.5 Hz. These fluctuations may interfere with human brain waves such as alpha (8–12 Hz), beta (12–30 Hz), and gamma (30–100 Hz)," Shi explains.
"The brain could then modulate neuroendocrine activity (for example, by altering the secretion of hormones such as vasopressin), which can gradually influence vascular tone and fluid balance. Such physiological adjustments may take weeks to accumulate, potentially explaining the observed 1-2 month delay."
"This is just a hypothesis," he stresses. "Further targeted studies are needed to confirm and clarify its potential mechanisms."
Want to learn more? The full paper may be found
here.
And today's observations from
Space Weather
BRIGHT FARSIDE CME: On Aug. 21st, a fast-moving CME blew away from the farside of the sun, forming a complete halo around the solar disk. The Solar and Heliospheric Observatory (SOHO) recorded the explosion:

Radio emissions from shock waves inside the CME suggest it was moving at 1,200 km/s (2.7 million mph)--very fast, but not record-setting. If it hit Earth, it would almost certainly spark a strong geomagnetic storm.
However, it will not hit Earth. Instead,
a NASA model predicts it will strike Mars on
Aug. 25th, potentially sparking
global UV auroras around the Red Planet.