Spectrographic determination of boron in steel

• Publisher: Elsevier Science
• Year: 1946
• Tongue: English
• Weight: 142 KB
• Volume: 241
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(46)90488-7

✦ Synopsis

~eonlagnetic storms were reported by"the Cheltenham, Md., magnetic observatory on March 4 to 6, March 9, and March IO to r I ; the last was the most severe, but the disturbance was much less severe than the one that accompanied the original sunspot group.

Daily warnings of radio propagation disturbance were issued by the Bureau on March 5 and 6 and again on March 9, extending to March I2.

There was not an exact 27 day recurrence of the prolonged ionospheric disturbance of February 7 through I I, which was forecast as a possibility for March 6 through 9 in the semiweekly forecasts issued March I and 5-Rather, there was slight to moderate radio propagation disturbance indicated on March 5, with moderate disturbance beginning March Io extending through March I I. Though the times of these disturbances did not show the expected relation with the central meridian passage of the sunspots, the region of the return sunspot group was the most likely source of disturbance visible on the sun.

Summarizing, severe radio and other terrestrial effects were very pronounced during the original passage of the sunspot group in February, and were less pronounced during its return in March.