25 June 2024 - Mission Day: 10434 - DOY: 177
Pick of The Week

Solar Activity Reality Check (February 12, 2004)

Hi-res TIF image (3.4M)

A glance at the sunspot number chart above shows that the number of sunspots continues its slide downwards as we move away from the solar maximum period of peak activity for this 11-year solar cycle. See our POTW from last June titled Sunspot numbers - a slippery slope down. And the numbers will generally continue to decline. Scientists track solar cycles by counting sunspots and this solar cycle reached its peak level in July 2000. Since then, the number of sunspots and general solar activity has gradually declined. Inevitably, the number of sunspots will follow this curve down until the numbers bottom out, sometime around 2006. Scientists also keep track of solar microwave flux, ultraviolet line emission, flare frequencies, and interplanetary disturbance frequencies as ways of measuring the solar and heliospheric cycle.

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Previous Picks of the Week

SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.

If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to steele.hill@gsfc.nasa.gov.


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Last modification: July 27, 2020

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