In which we are informed that that the Maunder Minimum was ‘an incident’, warming is due to ‘climate change’, and solar cycle 25 may not start until 2020.
Some fear that we could be heading to another Little Ice Age, but scientists say that’s unlikely, reports CBC News.
The sun is quiet … very quiet. In February, for the first time since August 2008, the sun went an entire month without any sunspots.
What does this mean for Earth?
In February, for the first time since August 2008, the sun went an entire month without any sunspots.
Sunspots are cooler regions of the sun. How many appear on the sun’s surface depends on what cycle the sun is in. Every 11 years our star goes through a maximum, followed by a minimum, also of 11 years (the entire cycle is 22 years).
Over the past three decades, the sun has been consistently dropping in activity. Maximum has been quieter than is typical; minimum has been particularly quiet. And this has caused some to make the false assumption that, as a result, Earth is going to cool.
It all stems from an incident that took place between 1645 and 1715, called the Maunder Minimum, where sunspots all but disappeared. This coincided with the “Little Ice Age” that stretched from 1500 to 1850 in the northern hemisphere. In England, the Thames River froze over; Viking settlers abandoned Greenland.
As a result, there have been strong suggestions that the Maunder Minimum caused the Little Ice Age, but some scientists warn that there were other contributors, such as increased volcanic activity.
On average, the sun produces 180 sunspots a cycle. The greatest ever was 285 in solar cycle 19; for solar cycle 24, so far it’s been 116.
So, with the decrease in solar activity, are we heading into another Maunder Minimum?
“No Maunder Minimum. Certainly no Little Ice Age,” said David Hathaway, an astrophysicist who once headed NASA’s solar physics branch at the Marshall Space Flight Center. “The next cycle looks like it’s going to be very much like this one.”
He explains that, while the sun does dim during a minimum, it’s only by a tenth of a per cent, which translates into a tenth of a degree Celsius. And with the warming by about 1C that we’ve seen due to climate change — and the warming that is to come — it’s unlikely that we’ll notice.
The sunspot cycle is also called the Schwabe cycle. At the moment we are at the end of cycle 24, heading toward 25. And scientists predict that this quiet trend is going to persist.
“There’s been this steady decline,” Hathaway said. “I’m fairly confident looking at our own predictions and predictions of others, that cycle 25 is going to be another small cycle.”
But it’s believed that the sun goes through many different cycles. Aside from the Schwabe, there is also one called the Gleissberg Cycle, where solar activity decreases roughly every 90 years.
And Hathaway said data over the past two centuries suggests that what the sun is now going through may be part of this cycle.
“We’ve now seen three or four of these modulations where we have small cycles, then they get bigger and then they get smaller again,” he said. “We’re at that bottom phase, where we haven’t seen cycles this small in 100 years.”
Full report here.
via Tallbloke’s Talkshop
March 11, 2019 at 05:12AM