Tag: sun

Signs of a sunspot ramp down

1:39 pm

The monthly update by NOAA of the solar cycle is out, showing the sunspot activity for the Sun in October, As I do every month, I am posting it here, with annotations to give it context.

Despite the appearance last month of the largest sunspot in almost a quarter century, the number of sunspots in October dropped significantly, bringing overall activity back to levels seen in 2012, prior to the second peak in the solar maximum. If things go as expected (not something I would bet much money on), the overall ramp down of sunspot activity should now continue over the next few years. There will obviously be jumps periodically, but the general output of sunspots should steadily decline.

I also want to reiterate what I noted last month, that the 2009 prediction of the solar scientist community is looking better and better with time. Other than over-estimating the total activity somewhat while missing the dip between the two peaks, their overall curve, indicated by the red line, is reasonably close to what has actually happened.

October 2014 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

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Largest sunspot in a quarter century spews flares

8:31 pm

The largest sunspot seen in about a quarter century produced another powerful X-class flare today, the sixth in less than a week.

This was the sixth X-class solar flare from NOAA 2192, a record for the number of X-class flares generated by a single group so far this solar cycle. It was also the fourth X-class flare since last Friday, continuing a period of intense flaring activity. This sunspot group has grown again a bit, and maintains its magnetic complexity. A degradation of the HF radio-communication was observed over South-America, the Caribbean, and West-Africa.

The last sentence is referring to some radio communications blackouts that have occurred in these areas because of the flares. For more information about the sunspot itself, go here.

And in case you hadn’t noticed, as predicted by many doomsday fear-mongers in the science community, our technological civilization was destroyed by these flares and we are now all dead.

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Solar minimum to limit interplanetary manned flights?

9:45 am

A new study suggests that the increased cosmic radiation reaching the inner solar system because of the Sun’s weak sunspot activity will increase the exposure to dangerous radiation levels for interplanetary astronauts, thus limiting mission lengths to about one year.

The new research finds that, during periods of low solar activity, a 30-year-old astronaut can spend roughly one year in space—just enough time to get to Mars and back—before the constant bombardment by cosmic rays pushes the risk of radiation-induced cancer above current exposure limits.

If the sun’s activity continues to weaken as many scientists predict, the number of days humans could spend in deep space before reaching their exposure limit could decrease by about 20 percent, making future crewed space flight more dangerous, according to the new study accepted for publication in Space Weather, a journal of the American Geophysical Union.

The numbers were worse for women, whose exposure would become dangerous in only 300 days, according to the study.

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A reviving solar maximum

12:32 pm

Last week NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in September. As I do every month, I am posting it here, below the fold, with annotations to give it context.

As much as I am always willing to point out the errors and foibles of scientists when they get something wrong or overstate their conclusions, I also believe it right to give credit when credit is due. I have been saying for several years now that the prediction of the solar scientist community, indicated by the red curve in the graph below the fold, had seriously overstated the Sun’s sunspot production during this solar maximum.

Well, it now appears that, as the solar cycle continues to run its course, that their May 2009 prediction is becoming increasingly correct.
» Read more

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The first of two coronal mass ejectors from a solar flare has arrived.

11:14 pm

An alert has been issued so that the electrical grids can been properly prepared to avoid damage by the impact of these two coronal mass ejections (CME) against the Earth’s magnetic field.

The first of the two CMEs predicted to arrive today made its appearance right on time. G1 ((Minor) geomagnetic storming is expected to begin within the next few hours with a maximum projected level of G2 (Moderate) storms for September 12th. A G3 (Strong) Geomagnetic Storm Watch is still in effect for September 13th due to the combined influence of this CME and the one projected to arrive late on the 12th. G1 (Minor) storming is likely to continue into September 14th. In addition, the S1 (Minor) solar radiation storm that is in progress as a result of the eruption on September 10th is expected to persist for the next few days with a possible slight increase with the arrival of the CMEs. Keep in mind that the forecast periods listed are in Universal Time so aurora watchers in the northern U.S. should be looking for possible activity tonight through Saturday night.

While there has been a lot of fear-mongering about these two CMEs, I expect that the only consequences we will see from both, the biggest to hit the Earth during this solar maximum, will be the possibility that the northern lights might be visible in places farther south than normal.

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The solar maximum lingers on

1:09 pm

On Monday NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in August. As I do every month, I am posting it here, below the fold, with annotations to give it context.

The sunspot activity of the Sun in August hovered at the same levels seen in July. Though the month had seen periods of little activity, these were interspersed with many violent flaring sunspots, including one that only yesterday unleashed a powerful X-class flare that is expected to send a coronal mass ejection directly at the Earth and should impact the Earth’s magnetic field on September 12. Expect spectacular auroras!
» Read more

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The lingering weak solar maximum

4:36 pm

On Monday NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in July. As I do every month, I am posting it here, below the fold, with annotations to give it context.

For the first time in four months the decline in sunspots ceased, though the sunspot count hardly rose either. Instead the numbers stayed almost the same in July as they were in June. This was during a month that began with lots of sunspots, and yet saw the first blank sun in almost three years. In fact, the Sun’s activity in July was a roller coaster, as noted by the Solar Influences Data Analysis Center (SIDC) of the Royal Observatory of Belgium.
» Read more

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The first blank Sun since 2011

1:03 am

No sunspots on July 17, 2014

For the first time since August 14, 2011, the Sun showed no sunspots on its surface today. It started the day, July 17, 2014, with one small sunspot, but that spot apparently decayed away by the end of the day, as indicated by the fact that the sunspot number for the day was listed as zero, the first time that has happened since the solar maximum ramp up began in 2011.

This is strong evidence that the ramp down to solar minimum is beginning.

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Communications to be lost with the Stereo spacecraft

9:53 am

Communications with the two solar-observing Stereo spacecraft will be cut off for more than a year, far longer than originally expected, as their orbits move them behind the Sun.

Unexpectedly high temperatures in the high gain antenna feed horns on both STEREO spacecraft will require corrective action in the coming months that will severely limit science operations. The high temperatures are being caused by the small angle between Earth and the Sun as seen from each spacecraft. In other words, pointing the antenna at Earth is putting too much solar heat on the antenna feed horn. To bring down the feed horn temperature, and preserve the spacecraft for years to come, the antennas will be pointed off at an angle from both Earth and the Sun, so that less heat will fall on the feed horns. Communication will still be possible using one of the antenna side lobes, but the telemetry rate will be extremely low. What instrument operations can be supported while the antennas are off-pointed is still being studied.

The spacecrafts’ orbit allows them to observe the back side of the Sun not visible from Earth. Though engineers had expected to lose communications for a period of time when the Sun moved between the spacecraft and the Earth, the blacked out time period has turned out to be much longer than planned. The shutdown will begin later this year with communications not resuming until January 2016.

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Is the Sun’s strange double-peaked solar maximum finally ending?

11:42 am

Last week NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in April. As I do every month, I am posting it here, with annotations to give it context.

May Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

For the third month in a row the Sun continued its drop in sunspots, with the total finally slipping below the 2009 prediction for this moment in the solar cycle. If this decline continues through to solar minimum, the shape of the solar maximum will essentially have been established, double-peaked with the second peak stronger than the first, something that solar scientists have never seen before.

At the moment I await word from the scientists that the Sun has completed the flip of its magnetic field polarity in the southern hemisphere. This flip has already occurred in the northern hemisphere, and when the south follows, the maximum will be officially over and we will officiallybegin the ramp down to solar minimum.

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