Solar, Space, and Geomagnetic Weather, Part 2

by Stephanie Osborn

“Interstellar Woman of Mystery,” rocket scientist and novelist

But wait! There’s more!

At Solar Max, the coronal holes move away from the Sun’s poles and group in with the sunspots, spewing high-speed solar particles out into the plane of the solar system.

At the end of every 11-year cycle, the magnetic orientation of the spots…flips. The end that was North becomes South, and the end that was South becomes North. It takes a whole ‘nother cycle to get back to the way it started out. So that’s a second solar cycle, the 22-year cycle.

In addition there are longer cycles that we are still working on figuring out, because they’re hundreds of years long, and it’s hard to get data that goes far enough back to chart those.

Now, sunspots look dark not because they’re cold, but because they’re just a bit cooler than the surrounding plasma of the photosphere (which is the visible “surface” of the Sun). If the photosphere is about 5,800°K (~10,500°F), then the sunspots are about 3,000-4,500°K (4,900-7,600°F). Still plenty hot enough to fry your turkey, but still several thousand degrees cooler than their surroundings. They can be teeny-tiny (relatively speaking, of course) or they can be huge things (80,000km/50,000mi – not too shabby when you consider the Earth is about 13,000km/8,000mi diameter) big enough to be seen by the naked eye (but don’t do that – we like having eyesight.)

So you might reasonably expect that during a solar max the Sun would be cooler, and send less energy out into space, right? Well, at first glance you might think so, but that isn’t really how it works. Remember, a sunspot is a big magnetic snarl. And the plasma around it follows the lines in that snarl. So we get all those great big loops – prominences and flares and things like that. Occasionally, like a snarl in your hair, the lines break – but unlike your hair, they reattach, producing really spectacular flares.

And then there are the CMEs. Coronal Mass Ejections.

I’m never quite sure how to best anthropomorphise a CME. Are they solar belches, or sneezes? Suffice it to say that all of that magnetic field mess around the sunspot group causes some sort of explosion. (No, we don’t know why. We do know it’s really, really complicated.) And it is like a giant nuclear bomb, blowing a big bubble of plasma away from the Sun at high speeds.

So between the coronal holes increasing both the speed and density of the solar wind, and these CMEs exploding into the solar system, the most active time for the Sun is in fact solar max, and that is when it’s pumping more energy into the solar system, not less.

-Stephanie Osborn

The Dragon Has Docked – no I never believed it was possible.

Its a fact. I would have bet any reasonable sum against this ever occurring. It is, in my humble opinion, the most significant thing to happen this decade. Yes, a lot more significant than 3D movies, wars in the Middle East, or the color of our president. All of those things were guaranteed to occur at some point, they simply chose to occur now. That this can be said of almost anything, short of the coming of Jesus on a cloud of Glory. Most points of history are simply things which are destined to occur at some time, so the timing isn’t particularly significant.

Of course, should the world end by any means, that is significant. However, commercial space flight is huge. It is a concept well developed in science fiction, but previously unknown in human history. True commercial exploration is the first step to commercialization of space, the purchase of the moon, human travel to the stars. We always had to assume that the bickering of nations would lead to ever greater space programs, but it became clear in the last decades that governments preferred to buy votes at home, not inspire people to great endeavors.

I hope, I pray, that this changes everything. I know the Earth is doomed, whether by the hand of God or a fiery missile from Oort. This planet will die someday. Will we die with it? Will we journey on into the cosmos? Maybe, just maybe, mankind will survive. This is that first step.

27CDB6E-AE6D-11cf-96B8-444553540000 width=400 height=292>

Solar, Space, and Geomagnetic Weather

by Stephanie Osborn

A lot of my friends and fans over on Facebook have become followers of my solar and aurora alerts there, and it has been suggested that I make this a regular part of my blog, so I thought I’d explain what it is and why it’s important.

All three – solar weather, space weather, and geomagnetic weather – are interconnected. This is because the Sun has a magnetic field that extends far past the Earth, and so the Earth’s magnetic field interacts with it. “Space Weather” is essentially a term for the conditions of space in the general vicinity of Earth, but not necessarily inside the Earths magnetic field.

We are also sitting inside the atmosphere of the Sun, the corona. It generates a wind, usually coming out from the Sun and spiraling away – yeah, the “solar wind.” Granted, the corona isn’t very dense, but it’s dense enough to create some effects, and we’re working on using it to our benefit, like in solar sails and such, which can use the solar wind as much as light pressure (different blog post) to maneuver around the Solar System like the spaceborne clipper ships of old.

But when the Sun gets…agitated, we’ll say…it can get a lot denser. Coronal holes move from the poles down to lower latitudes, and the Sun’s face develops an astronomical case of acne. This usually occurs around the time of solar maximum.

Whoa. Waitaminit. What’s “solar maximum”?

Our Sun has cycles that it goes through. Some are short and some are long. These cycles are related to its magnetic field and to sunspots. In fact, many variable star astronomers such as myself consider that the Sun is at least a borderline variable star because of this; some consider it outright variable. We’ll leave that to a later discussion. For now, let’s just look at those cycles and why they exist.

The Sun is a gigantic ball of plasma, a gas of ionized particules like protons and electrons. It spins on an axis. These two facts, when combined, create an electic current. An electric current, in turn, generates a magnetic field. This is why the Sun has a magnetic field, and it looks like a bar magnet – a “dipole.” (Remember elementary school when you put a piece of paper on a bar magnet and sprinkled iron filings on it? It made a cool bunch of lines that arced from one end of the magnet to the other, and then fanned out at the very ends. That’s what I’m talking about.) The polar areas normally have “coronal holes,” because of the open-ended lines. The plasma flows out, away from the Sun, at high speeds (200-600km/s, or 447,000mph).

But since the Sun isn’t solid like a bar magnet, the plasma doesn’t all have to spin around the axis at the same speed – and it doesn’t. The poles don’t spin at the same rate as the equator, and the deeper layers don’t spin at the same rate as the surface.

So let’s think about those lines of iron filings again. Our bar magnet has gone and gotten itself all twisted up because it isn’t solid, so the lines of iron filings get all twisted up, too. Now, scientists are still working on this, but the best we can figure out now is that sunspots are places where “snarls” form in the magnetic lines, and break through to the surface. (In the last couple of years we’ve learned how to look “deeper” into the Sun to see these snarls below the visible surface. Remember that. It’ll come into play later on, when we start talking about the Sun as a variable star.) This means that sunspots have magnetic fields, sometimes very complicated. There are almost always at least two – one is a north magnetic pole, the other a south pole. (When there is just one, it is usually funny-shaped and one end will be North and the opposite end South. And sometimes there’s a whole cluster, which gets really complicated.) And most all of the spots on the Sun will have the same N/S orientation.

It turns out that every 11 years, there is a peak in the number of sunspots, and a minimum in the number of sunspots. We aren’t quite sure why, because we don’t have all the theory worked out yet. But we’ve all heard of Solar Maximum and Solar Minimum, and that’s what those terms mean. Solar Max is when we have the most spots, and Solar Min is when we have the least.

 -Stephanie Osborn

Solar Maximum – 2012

Look, I’m just better at modeling curves than anyone who apparently ever worked for NASA. I can’t explain how bad the Solar Modeling people have gotten. Year after year they revise down their estimates…without reaching the bottom I predicted near 5 years ago. Oddly enough, instead of proving me an idiot, the sun has gone and made 2012 its maximum. Sure, i could still be wrong. Lets have a huge May sunspot number and keep going till 2014.  Or start petering out after Christmas like I predicted more than 5 years ago.

Now, I didn’t predict a Dalton minimum. I said it was possible given the evidence, but my prediction is just for a very low sunspot number. I don’t see that the peak of the cycle has strayed a bit from 2012, so dead on where it was predicted in 2001. If the cycle does an extended minimum a second time, as we saw in 2009… then maybe I’d be convinced that we had started a Dalton minimum.  Right now I just think it is plausible. I think it is equally probably that 2023 will be a cycle with a reasonable sunspot number in the upper 80’s to low 90’s and a couple of x class storms to write home about.

The funny thing is, if you do a model progression on the sun, it is a lot like the weather. It tends to do the same thing over and over again, but with changes each time. The changes aren’t unpredictable, but they don’t pattern well to computers. They pattern fairly well to the human eye. Can’t explain why the computers don’t see the patterns and the humans do, but it does seem to be the case that the human observers are putting out much better predictions than the models. Yeah, I think we can extend that observation to a lot of other “scientific” fields as well.

Big Changes

Well, i hadn’t really assumed that working for a living would give me a lot of free time. More significantly, under the new security arrangements, I have to be very careful about things I might talk about. Yes, I’m back to being a rocket scientist. However, this rocket is national security. Oddly enough, my hobby work is Homeland security. Yeah, I get to do Top Secret work for fun.

Since both of these topics would have been a lot of fun to blog about, I may need to re-consider my basic blog topics.  Religion? Politics? Books? I know, I’ve been a second rate news accumulator for the Science and anti-global warming folks for years. Not sure what I’m going to do for a blog now.

Feel free to comment away. I’ll take any suggestions to heart.