In my post from yesterday, I highlighted a paragraph from a NASA press release which touched on one of the final findings of the soon to be ended Ulysses spacecraft mission to study the sun:
“Ulysses ends its career after revealing that the magnetic field emanating from the sun’s poles is much weaker than previously observed. This could mean the upcoming solar maximum period will be less intense than in recent history. “
A few months ago, I had plotted the Average Geomagnetic Planetary Index (Ap) which is a measure of the solar magnetic field strength but also daily index determined from running averages of eight Ap index values. Call it a common yardstick (or meterstick) for solar magnetic activity.
Click for a larger image
I had noted that there was a curious step function in 2005, almost as if something had “switched off”.
Today, since it is fathers day, and I get to do whatever I want, I chose to revisit this graph. Later I plan to take my children to launch model rockets, but for now, here are some interesting new things I’ve found.
First, I’ve updated the original Ap graph to June 2008 as you can see below.
Click for a larger image
Source data, NOAA Space Weather Prediction Center:
http://www.swpc.noaa.gov/ftpdir/weekly/RecentIndices.txt
As you can see, the Ap Index has continued along at the low level (slightly above zero) that was established during the drop in October 2005. As of June 2008, we now have 32 months of the Ap hovering around a value just slightly above zero, with occasional blips of noise.
Since it is provided in the same dataset, I decided to also plot the smoothed Ap Index. I had noted to myself back in February that the smoothed Ap Index had dropped to minus 1.0. I figured it was just an artifact of the smoothing algorithm, but today that number remains there, and there doesn’t appear to be any change even though we’ve had a bit of noise in March that put the Ap Index back up to 10 for that month.
I also plotted my own 24 month smoothing window plot, shown in magenta.
Click for a larger image
I find it curious that the smoothed value provided by SWPC remains at -1. I figure if it is a software error, they would have noted and fixed it by now, and if they haven’t then perhaps they are standing by the number. Odd. One possibility may be that they are using a 12 month fixed window, instead of a moving window month to month. If so, then why show the -1.0 data values? Put nulls — in the dataset.
UPDATE: Astute reader Jorma Kaskiseiväs points out something I missed. The explanation is in the header for the dataset file, a short note: # Missing data: -1″. I was looking in the companion readme file for an explanation. Thanks for pointing this out. Surprising though that SWPC does not use a running average. Easy to do as I’ve shown.
While I was searching for something that could explain this, I came across this plot from NOAA’s NGDC which was used to illustrate solar storm frequency related to sunspots:
Click for original source image, a larger plot is here via FTP link.
But what I found was most interesting was the data file they provided, which had the number of days in a year where the Ap Index exceeded 40. You can view that data file yourself here via FTP link. The accompanying readme file for the data is also available here.
What is most striking is that since 1932, there have not been ANY years prior to 2007 that have zero data. The closest was 1996:
1996 0 0 0 0 0 0 0 0 0 1 0 0 1
———————————————————–
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTAL
———————————————————–
2005 3 0 2 1 3 2 2 2 3 0 0 0 18
2006 0 0 1 2 0 0 0 1 0 0 0 1 5
2007 0 0 0 0 0 0 0 0 0 0 0 0 0
2008 0 0 0 0 0 0
Now we have almost two years.
Here is my plot of the above dataset:
Click for a larger image
I also decided to plot the 10.7 centimeter band solar radio flux, also a metric of solar activity. It is in the same SWPC dataset file as the Ap Index, in columns 8 and 9. Oddly the smoothed 10.7 CM flux value provided by SWPC also has dropped precipitously and stayed there. I also provided my own 24 month wind smoothed value which is plotted in magenta.
Click for a larger image
Like the smoothed Ap Index, it has also stayed that way a few months. NOTE: The data past Dec 2007 on the blue line from SWPC is not valid. The smoothed 24 month window is.
Either way it appears we continue to slide into a deeper than normal solar minima, one not seen in decades. Given the signs, I think we are about to embark upon a grand experiment, over which we have no control.
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I still don’t buy it.
The only thing that racks up real numbers is the impact of ethanol and bad harvests. The other stuff doesn’t add up to a hill of beans, and some of it I just outright dispute (if you want tainted food, just go back before refrigeration and germ theory).
I’d be interested in actual numbers on the grain issue though.
Higher elevation farming microcosms allow an interesting review of produce changes that manage to stay on top of temperature changes. Instead of domestic cows, sheep rise to the top when it gets cold. Instead of row crops, winter wheat becomes King. Instead of slow growing crops (melons), cool season crops (peas) get planted. Instead of crops that produce above ground food (tomatoes), crops that produce below ground food (potatoes) are planted. There will be pockets of producers that will once again be able to ship out of the area. These small communities will likely be hit less severely than areas that have grown rapidly as a result of a warmer, sunnier climate while still being surrounded by lush vegetation.
I’m trying to find some relationship between the sun and temperature on earth. I can see that the sun activity is going down, and so is the recent temperature data. But solar activity seems to move in a sine function, so it’s hard to see the link between long term solar activity (sine function) and temperature (with an up trend). I’d like someone to show me this link, otherwise the information on the sun that keeps being posted will seem a little useless. Thanks.
David:
http://icecap.us/index.php/go/about-climate-change
I have a geological question.
If the earth either warms or cools signicantly (>1 degrees C or so) very rapidly (in geologic time), would earthquakes happen more frequently as the earth’s crust warms up and expands or as the earth cools down and contracts?
REPLY: Ah, the bait question, soon to be answered.
[…] So what does a defeated budget mean? What does it tell us about our town? If last November’s election is any indication, it means nothing about the future makeup of the Town Council — West Hartford voted solidly for the same people — and the same party — despite the ‘07 referendum. And it likely doesn’t mean much about what the budget will ultimately look like … the odds that this council will produce a budget that does not reflect a tax increase are slimmer than the odds of the sun burning out. […]
Leif:
Could you provide input on the rotation differences along sun latitudes? When magnetic ropes get all coiled up and burst to the surface is it because the different rotation speeds cause these magnetic ropes to coil up, especially if the magnetic ropes cross latitudes that are rotating as different speeds? Or do they coil up on their own even if the sun rotated at the same relative speed at each latitude? And if the coils are the result of different rotation speeds, what were to happen if the different speeds occasionally and predictably were in synch with each other (like windshield wipers on a school bus)? Is there data on rotation speeds, or more to the point, differentials, over time?
[…] we see. There are sunspot affects, and now more NOAA data showing that the Sun’s magnetic field is doing its part as well. A few months ago, I had plotted the Average Geomagnetic Planetary Index […]
[…] http://wattsupwiththat.wordpress.com/2008/06/15/more-signs-of-the-sun-slowing-down/ […]
[…] Excerpt: It appears we continue to slide into a deeper than normal solar minima, one not seen in decades. Given the signs, I think we are about to embark upon a grand experiment, over which we have no control […] I had noted that there was a curios step function in 2005, almost as if something had “switched off” […] As you can see, the Ap Index has continued along at the low level (slightly above zero) that was established during the drop in October 2005. As of June 2008, we now have 32 months of the Ap hovering around a value just slightly above zero, with occasional blips of noise. […] What is most striking is that since 1932, there have not been ANY years prior to 2007 that have zero data. […] (Whatsupwiththat…) […]