The Sun's 'Quiet Period' Explained 167
Arvisp writes with this excerpt from the BBC:
"Solar physicists may have discovered why the Sun recently experienced a prolonged period of weak activity. The most recent so-called 'solar minimum' occurred in December 2008. Its drawn-out nature extended the total length of the last solar cycle — the repeating cycle of the Sun's activity — to 12.6 years, making it the longest in almost 200 years. The new research suggests that the longer-than-expected period of weak activity may have been linked to changes in the way a hot soup of charged particles called plasma circulated in the Sun."
hot soup? (Score:5, Informative)
This is slashdot, not preschool. You can use your big-boy words with us.
Re:Finally... (Score:5, Informative)
In the 70s it wasn't clear which effect was winning, cooling due to aerosal particles (soot) in the atmosphere or warming due to carbon dioxide and other greenhouse gases. It turns out that warming was winning which became clear in the late 70s and 80s. There was no consensus at any time saying that global cooling would be a problem long term. However, this debate did get mixed together with the discovery of the orbital cycles which cause the ice ages which predict another one thousands of years from now . So you got some popular science articles warning about global cooling and a new ice age.
Funny? No, more like Tragically stupid (Score:1, Informative)
Grow up. Trolling doesn't add to the discussion. just because you're a scientifically illerate fool who puts your politics before science doesn't mean
A) that AGW doesn't exist
B) that scientists don't know how the sun works and haven't already accounted for it's energy variations
C) that people who disagree with you are doing so for political reasons
D) that anyone has ever tried to blame everything on global warming
E) that weather is climate and climate is weather
F) that your back yard is representative of the real world
Hint: at the bottom of that solar minimum we were STILL WARMING, though we did detetct a slowing of the warming trend that can be directly connected to the lowering activity. a slowing, not a cessation of warming, not a reversal.
Re:Cycle my ass ... (Score:5, Informative)
Give me a break. The solar activity cycle has been documented and studied since the early '60's (if not prior). We use it to design appropriately rad-hardened components in the spacecraft industry. We analyze required mission lifetimes and chart solar activity for the projected lifespan of the spacecraft as variations in solar activity affect everything from solar cell degradation to magnetic drag induced on your spacecraft. Hell, I can eve give you a citation. Go find yourself a copy of Fundamentals of Space Systems ed. II by Vincent L. Pisacane. Crack it open to Chapter II: The Space Environment. Read pages 50 through 60. It's all laid out in the basics there. If you want more detailed info. go crack into a journal of astrophysics sometime....
So put away the hatred of science and go back to doing whatever it is you do.
Of course, if you were being sarcastic and/or satirical, I completely failed to pick up on it due to a lack of sarcasm tags around your post.
Re:are we really surprised? (Score:5, Informative)
The sun is 4.6 BILLION years old and we are concerned with a couple of years difference in the Solar Cycle? How many of our empirical evidence cycles have we measured in this sort of accuracy? The whole cycle measures within 2.3e-8% of its lifespan and we are surprised that we haven't got the accuracy narrowed down? What other natural phenomenon have we measured to this accuracy cause I would really like to see the ruler that was used...
What got your panties in a twist? Just because something might vary over 4.8 Billion years has nothing to do with the fact that based on our current set of measurements this period was a bit longer. Hell, it doesn't matter if we measured only ONE other cycle, we could STILL make the observation "Hey, this cycle is longer than the last one".
However since you did ask. Sunspots were what we first used as a 'ruler'. Discovered in 800 BC, drawn later, and eventually the cycle was first showin in 1843 using data going back to 1755. We now know sunspot data (from historical observations not always available to the first discoverers of the cycle) going back to 1610.
And it's not like it's a 'slight' cycle either. These things vary by 150+ appearances per day during the peak, down to a dozen or fewer during the minimum.
Take a look at this picture: http://solarscience.msfc.nasa.gov/images/Zurich_Color_Small.jpg [nasa.gov]
You don't exactly have to be a statistical wizard to see a pattern in that data.
Re:This is why I hate most science reporting (Score:5, Informative)
Plasma flowing poleward at the solar surface and returning equatorward near the base of the convection zone, called the meridional circulation, constitutes the Sun's conveyor-belt. Just as the Earth's great oceanic conveyor-belt carries thermal signatures that determine El Nino events, the Sun's conveyor-belt determines timing, amplitude and shape of a solar cycle in flux-transport type dynamos. In cycle 23, the Sun's surface poleward meridional flow extended all the way to the pole, while in cycle 22 it switched to equatorward near 60. Simulations from a flux-transport dynamo model including these observed differences in meridional circulation show that the transport of dynamo-generated magnetic flux via the longer conveyor-belt, with slower return-flow in cycle 23 compared to that in cycle 22, may have caused the longer duration of cycle 23.
Re:This is why I hate most science reporting (Score:3, Informative)
I totally agree with you, this is too insubstantial even for science reporting.
The article is at adsabs, but it's on subscription only:
http://adsabs.harvard.edu/abs/2010GeoRL..3714107D [harvard.edu]
Maybe someone with a subscription to "Geophysical Research Letters" could voice an opinion?
Re:Solar Cooling! Man is at it again! (Score:4, Informative)
Trying for "funny" is dangerous to your karma. If you succeed, people get a good laugh but your karma's the same. If you fail, you're going to be modded troll, flamebait, overrated, or offtopic and your karma will suffer. Even if your joke just isn't funny.
The moral? Shy away from humor unless you don't care about karma or you're sure you joke will make somebody spew coffee out of their nose. And sorry, but your joke just didn't cut it.
Re:Climate change (Score:2, Informative)
Yeah, the sunspots themselves are cooler, but total solar irradiance is lower during a solar minimum, and higher during solar maximum [wikipedia.org]. So while I am not saying for a fact that you don't know what the hell you're talking about and are stupid for still thinking it's just the sun... Wait that's exactly what I'm saying.
Re:Good thing (Score:3, Informative)
yet another troll. as was pointed out above, this solar cycle was a minimum of activity (i.e. less solar energy incoming on earth) and during this same period, the temperature still went up. not that climate change is actually about such short spans of time, but your jumped to conclusion isn't even supported anecdotally by this evidence.
Re:Finally... (Score:1, Informative)
They changed it to be "climate change" some time ago so no matter if the globe "cools" or "warms", some people can equally claim the sky is falling and push through their unrelated political agendas.
It's nice to hear from Slashdot's "partisan dumbass" constituency, but that has nothing to do with the history of the term.
"Global warming" was first used, AFAIK, by Wally Broecker in 1975, but for most of the 1970s and 1980s, most papers on the subject didn't use the term. "Climate change" was sometimes used, and note that the "CC" in the abbreviation IPCC (founded in 1988) refers to "climate change".
"Global warming" entered the public vocabulary mostly in 1988 after James Hansen's testimony to Congress. Scientists continued to talk about "climate change" among themselves, but increasingly used "global warming" when speaking to the public, as that's what was being used in newspapers.
After increased concern about thermohaline circulation collapse (which can cause localized cooling in response to overall warming), public confusion between weather and climate (a cold winter doesn't mean the globe isn't warming), and realization that the public was ignoring important non-temperature impacts (such as precipitation changes), scientists reverted back to "climate change" when speaking to the public. But, again, amongst themselves they have pretty much always used the term "climate change".
Re:Inactivity? (Score:3, Informative)
Funny how things go full circle. Once (some of) our ancestors consulted the Oracle [wikipedia.org] and worshipped the Sun [wikipedia.org]. Now we ... gee, I dunno.