<p>The observation is not of an exact &quot;period&quot; but more generally that 3-5 sunspot cycles with lower activity tend to be followed by 3-5 with stronger activity. Since a cycle is roughly 11 years, there appears to be a cycle of about 8×11 = 88 years.  This is the Gleissberg cycle.</p>
<p>But the length of each cycle is different, so it doesn't have an exact period.  And even though there are several hundred years of sunspot data, there haven't been enough Gleissberg cycles to confidently give an &quot;average&quot;.</p>
<p>So you are left where you started.  The Gleissberg cycle is variable and &quot;about 88 years&quot; or &quot;in the range 80-100 years&quot;</p>

CC BY-SA 4.0
2024-05-06T17:51:58.030Z
2024-05-06T17:51:58.030Z
James K
<p>What is the most commonly used length for the <strong>Gleissberg Cycle</strong> of sunspots? I have reviewed academic literature on the subject and the lengths used are all over the place. Specifically, anywhere in the 80-100 years range. If I had to guess, I would say 88 years since that is the length that Gleissberg himself used.</p>

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2024-05-03T21:11:04.810Z
It seems likely that it doesn't have an exact period,  some cycles last longer than others.
James K
<observational-astronomy><the-sun><stellar-astrophysics><sunspots>
Most established length of Gleissberg Cycle
Daniel J Rice
# Most established length of Gleissberg Cycle

(Asked by: username_0 on 2024-05-03)

What is the most commonly used length for the **Gleissberg Cycle** of sunspots? I have reviewed academic literature on the subject and the lengths used are all over the place. Specifically, anywhere in the 80-100 years range. If I had to guess, I would say 88 years since that is the length that Gleissberg himself used.

**Tags:** observational-astronomy, the-sun, stellar-astrophysics, sunspots

> **Comments:**
> **username_1**: It seems likely that it doesn't have an exact period,  some cycles last longer than others.  

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## 1 answers

### Answer by username_1 on 2024-05-06. Score: 3

The observation is not of an exact "period" but more generally that 3-5 sunspot cycles with lower activity tend to be followed by 3-5 with stronger activity. Since a cycle is roughly 11 years, there appears to be a cycle of about 8×11 = 88 years. This is the Gleissberg cycle.

But the length of each cycle is different, so it doesn't have an exact period. And even though there are several hundred years of sunspot data, there haven't been enough Gleissberg cycles to confidently give an "average".

So you are left where you started. The Gleissberg cycle is variable and "about 88 years" or "in the range 80-100 years"


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