Sunspot AR1476 may have some surprises for us in the coming days, and I hope it isn’t a Carrington type event. It has already launched two CME’s yesterday.
From NASA’s Spaceweather.com: A pair of solar eruptions on May 7th hurled coronal masss ejections (CMEs) toward Earth. Forecast tracks prepared by analysts at the Goddard Space Weather Lab suggests that clouds with arrive in succession on May 9th at 13:40 UT and May 10th at 07:54 UT (+/- 7 hours). The double impact could spark moderate geomagnetic storms. High-latitude sky watchers should be alert for auroras.
With a least four dark cores larger than Earth, AR1476 sprawls more than 100,000 km from end to end, and makes an easy target for backyard solar telescopes. Amateur astronomer Alan Friedman sends this picture of the behemoth from his backyard in Buffalo, NY:
“AR1476 is firecrackler,” says Friedman.
Indeed, the active region is crackling with impulsive M-class solar flares. Based on the sunspot’s complex ‘beta-gamma’ magnetic field, NOAA forecasters estimate a 75% chance of more M-flares during the next 24 hours. There is also a 10% chance of powerful X-flares.
“This one is going to be fun as it turns to face us!” predicts Friedman. He might be right.
Here’s the current SDO image:
And a close up of AR1476:
Keep up with the latest at the WUWT Solar Reference Page
On solarham.com, the farside view indicates a series of previously numbered sunspots are coming around again. They’ll be renumbered, but they might be on their way out. Seems SN is on its way back down, and SFI will follow back down. That doesn’t mean 1476 won’t be very interesting. It’s just tiring how the media test run more scary stories.
http://www.wired.com/wiredscience/tag/carrington-event/
However, if we can’t get some backup transformers for power plant generators, we’ll be in a very tough spot if a serious flare destroys them.
http://bigpictureone.wordpress.com/tag/carrington-event/
There is a serious threat we should deal with, but it has more to do with famine and disease than burning alive as in that ridiculous movie “Knowing”.
http://en.wikipedia.org/wiki/Knowing_(film)
Nah. Basic rule with astronomical events like comets or sunspots: The dramatic events will be a complete surprise. The announced and pre-panicked events will be fizzles.
Can anyone tell me how a Carrington event would impact HVDC interties? It seems to me that they do not have the vulnerabilities that HVAC interties have. Should we be building all new interties as HVDC?
Need to get the SCT daytime polar aligned to get some shots of this plus the practice will be beneficial for the May 21 annular solar eclipse and the June 5 Venus transit. Would need to be very lucky to catch a CME event at the same time but you never know.
There will be a ANNULAR SOLAR ECLIPSE on the 20-21st of May this month and a partial eclipse visible to much of the US, Canada, Russia and China.
It should be Spectacular to see, but even more so if the sun becomes active with large flares around this date IMO.
See here for a list of places that it will be visible to; http://astro.ukho.gov.uk/eclipse/0132012/
“An annular eclipse occurs when the Sun and Moon are exactly in line, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or annulus, surrounding the outline of the Moon”. ~wikipedia
Kinda looks like the Hawaiian Islands. Is this a common occurrence?
Yeah, I noticed that large sunspot group just appearing on the limb couple days ago. Looked like a biggie.
Sun magnetic activity may be relatively low, but nothing like a Maunder Min, when sunspots virtually disappeared for decades.
I keep hearing about the devastation to be caused by a Carrington event, especially to the big grid transformers. Large CME’s are observed in advance by satellites and only travel at a maximum speed of 3200 km/s which would give us many hours of warning. I would think the grid operators would have plans to unplug the transformers for such an event. Am I missing something?
Donald Mitchell says:
May 8, 2012 at 12:44 pm
Can anyone tell me how a Carrington event would impact HVDC interties? It seems to me that they do not have the vulnerabilities that HVAC interties have. Should we be building all new interties as HVDC?
I am unfamiliar with the term “interties”. Is that some sort of transformer? Or is that British for inverter?
Nevertheless, it is possible to rebuild (rewind) a transformer in short order. Any shop that can handle large industrial motors should be able to deal with it on an emergency basis. Systems with properly co-ordinated circuit breakers should experience minimal damage.
Transmission of electricity via DC is not terribly efficient until you get in the 500kv + range. So there is not a lot of them (transmission lines) around. If you had to replace/rewind every distribution transformer in the United States for example it would take at least 2 years. There will not be anywhere near that level of damage even with a direct hit.
RobR says:
May 8, 2012 at 2:20 pm
I keep hearing about the devastation to be caused by a Carrington event, especially to the big grid transformers. Large CME’s are observed in advance by satellites and only travel at a maximum speed of 3200 km/s which would give us many hours of warning. I would think the grid operators would have plans to unplug the transformers for such an event. Am I missing something?
You are making the assumption that at working level where they have been told to ‘maintain supply, that they will actually start disconnecting their main transformers when there seem to be no problems and the game is just starting. I would think that the layers of bureaucracy in the power companies would lead to a level of inertia that means approval hedged around with caveats, would arrive around a day after the CME.
I would envisage that some of these systems are not designed to be disconnected and isolated with ease. Perhaps someone should ask the power companies how fast they could disconnect and isolate their systems given a few hours warning.
Rob – the grid is a delicately balanced generation vs load system. Taking transformers out of service requires a arbitrary load reduction (aka blackout). All anyone can do is preposition transformers at key positions and have crews on standby. Always remember, with electrical grids – power delivered must always equal power demand… If it doesn’t the grid collapses. Transformers are the gateway into and out of the system. GK
These fire crackers may be doing more than we know or suspect.
http://www.vukcevic.talktalk.net/TMC.htm
note correlation, spectral power distribution and then very odd percentage disparity between the incoming TSI and what is happening some 3000km below the Earth’s surface. Our planet has many amazing secrets.
“but soft, what light through yonder window breaks
it is the east and AR 1476 is the sun’
with apologies to the bard
It has the comma-shape. Likely the residents of the Sun are under a solar tornado-watch.
Meanwhile, here in New Hampshire, it’s cold and the clouds don’t seem to want to burn off. I plod across my muddy garden, stroke the white bristles on my chin, gaze sagely at the sky, and mutter, “It’s them durn cosmic rays.”
Hopefully a big sunspot will shoo away the cosmic rays for a bit, and the clouds will dry up. Sunshine is scarce. When it comes, it comes with north winds and frost. (After a hot spell in March had folk hopeful, and talking about a long and warm summer, moods have turned towards grumpiness, and those who planted early have paid the price.)
A garden is a better indicator of what is happening than weather records. The temperatures up in Concord, New Hampshire are messed up by hot spells in both March and April which make both months appear warm. A three day hot spell, with temperatures 20 degrees above normal, can make a whole month look warm, in the averages, but it takes only a single calm night, less than ten degrees below normal, to make a frost that can kill even cabbages, when they are tender seedlings.
There is a funny thing that happens to northern plants when they are exposed to cold. Perhaps a biologist can explain it. You see it in hardy plants that refuse to wither when exposed to frost, such as checkerberries, certain ground-hugging brambles, certain tough grasses, the early shoots of plants such as goldenrod, and the first shoots of swamp maple. When it is very cold they give up on green chlorophyll, and make some sort of purple stuff. We’ve been hit by enough hard frosts, after early growth, to have a lot of plants using the tactic, whatever it is, that turns them purple. I’ve even seen some ordinary grass with a purple tint, in early May.
In other words, there is some very real cold in this air this spring. It doesn’t show up in the averages, which make both March and April look above normal up here. However the plants know about it.
Therefore I’m rooting for more sunspots, and fewer cosmic rays. Let the clouds burn off, and the sun shine down.
I cannot share it, but you can skim through some or get your wallet out 🙂
http://www.nap.edu/catalog.php?record_id=12507#description
Check that. It is free to read online.
http://www.nap.edu/catalog.php?record_id=12507#description
How frustrating. Last time this group was chucking stuff our way, I checked the Aurora site and saw the Aurora Australis would have been readily visible from Auckland—like, right overhead!
The weather had other ideas with dense horizon-to-horizon cloud and heavy rain.
This time—it’s an exact repeat of last time. Weeks of cloudless skies day and night, and now horizon-to-horizon dense cloud … with heavy rain.
*Expletive deleted*
About the “World Climate Widget”. It seems stuck at 25/93 (and 0.11°, 392 and March 2012). I’m tempted to see if I can create my own. WUWT?
Sparks says:
May 8, 2012 at 1:11 pm
I saw an annular eclipse (no need to shout) once (Plymouth NH, 1995 or so). It wasn’t spectacular. The quality of the light after the Sun was 9% covered or so was very odd, and very hard to describe. Shadows were sharper, but weird too. Looking at the Sun was painful, thanks to dilated pupils. The most interesting thing to me was the start of annularity through my telescope. When I was a kid I liked to watch the movement of the minute hand on a large clock my grandparents had. With care, I could see the movement of the hour hand. The start of annularity was the first time I saw movement of a 29 day clock “element.”
Don’t expect to see solar flares. I doesn’t take much light from the Sun’s “surface” to outshine ejected plasma into invisibility.
I haven’t seen a total solar eclipse. I really should fix that someday. They’re a completely different event.
Oh – my brother and found that one of the best places to watch a partial solar eclipse from is in a maple tree. The deep notches in the leaves make thousands of pinhole cameras projecting images of the Sun in varying brightness and size on the leaves below.
Yes; Oh noes! We’re going to go ‘dark’ and there is not ‘thing one’ we can do about it!
/sarc
(As if we have not learned something from past events, and we have … the public, however, it seems has this ‘static’ view of the situation no matter how much one lone, sole, poster
attempts to add some sanity to the mix.)
.
Hoser says:
“However, if we can’t get some backup transformers for power plant generators, we’ll be in a very tough spot if a serious flare destroys them.”
Once again, the doom and gloom surrounding a Carrington-like Event is peddled. The statement above is wildly exaggerated and has been discussed at WUWT recently via U.S. DHS concerns about the same – http://wattsupwiththat.com/2012/02/14/homeland-security-takes-on-the-carrington-event/ .
“There is a serious threat we should deal with, but it has more to do with famine and disease than burning alive as in that ridiculous movie ‘Knowing’.”
The movie was never marketed as non-fiction and was (I thought anyway) a sci-fi thriller intended purely for entertainment. But… how would a Carrington-like Event lead to “famine and disease” when its namesake did not?
I find that as soon as a spot like this appears and is publicised widely, then that ussually puts the kiss of death on it and little happens mostly!
Oh my God, run and hide in the storm cellar! You remember the last time a solar storm sucked up Dorothy and sent her to Oz, don’cha?
I said it before, and I’ll say it again. Solar storms are just another tool the alarmists use to scare people so government can loot more of our money.
G. Karst says:
May 8, 2012 at 2:47 pm
But come on, you would have hours to spin down the turbines and unhook the system. Yeah, you may have to black out the system for hours or even a day but this whole end of the grid thing. I have to believe, there are sane people in charge with contingency plans. I just can’t buy the catastrophe thing.
Ian W says:
May 8, 2012 at 2:44 pm
I would envisage that some of these systems are not designed to be disconnected and isolated with ease.
“envisage” what you want, but these folks are in to make a profit and losing there customers for a long period of time is as they say counter productive.
proof read, proof read and still write there instead of their. oh well.
I certainly never suggested any catastrophe! I was merely explaining the difficulty of transformer outages. Of course there are contingency plans – they are called “load shedding” schemes and there exists an orderly sequence of emergency blackouts. It is a tough trigger to pull based solely on predicted effects. Past prediction effects, which failed to materialize, will probably increase reluctance. It would be career ending and a very expensive hit for the economy…if wrong.
A grid collapse can be of a very short duration and re-energized and orderly re-loaded. It all depends on the exact equipment damaged. Just like any black-out that has ever happened before. Some sections come back quickly – others must wait for parts and repair. It is just another part, of the human condition. GK
Caleb,
Temperature drives the NO3 cycle usually making the aerial parts of growing plants enzyme nitrate reductase LESS active in cooler night (than daytime). Your cold snap counts as a driver to diminish that enzyme protein expression. Thus it is temperature & not light/dark cycle dominating the N03 flux from roots into shoots. Although night temps of 30*C (86*F) let a plant keep feeding at night it is nitrate reductase getting NO3 that controls rate plant uses Nitrogen.
Plant vacuole is where NO3 sequestered & not immediately available until sequestration has to be overcome by osmotic changes to translocate it (leaf stoma closed also stalls sequestrated NO3) . Ions selected for transport rely on cation induced conformational changes in plant cell membrane structures (or sometimes ion carriers). Polyvalent cations alter membrane groups to change the surface selection of what is permiabile (cations bind to ion carrier reactive sites & modify the ion carrier’s enzyme protein). So, a cold snap depresses Nitrogen getting diffused in aerial plant parts contributing to green color loss & also other cations begin cold weather functional shifts.
The purple is a shift to mobilization of Iron cation reactions instead of Calcium’s usual influence at the plant’s membranes (Calcium ion deficiency distorts new growth). Tomato seedling stems are often purple and tissue analysis shows low Phosphorus. Those seedlings roots don’t supply adequate Nitrogen needed to bring much Phosphorus to seedling. Then the normal Phosphorus inhibitory competition of Iron is not going on (too much Phosphorus excessively holds Iron unavailable ).
Once an untimely cold snap fosters polyvalent Iron jumping into play the plant tissue’s Phenyl propanoid pathway takes cells molecules of chalcone flavone, converts that to dihydroflavonol, then 3,4 diol, then 3 hydroxyanthocyanidin and finally into one of the 30 different known anthocyanins (molecule we see as purple in plant). Those cold crisis induced purple anthocyanins are a cellular protective molecule against oxygen radicals the a stressed plant is putting out; plant varieties have unique stress limits.
RobR says:
May 8, 2012 at 2:20 pm
I keep hearing about the devastation to be caused by a Carrington event, especially to the big grid transformers. Large CME’s are observed in advance by satellites and only travel at a maximum speed of 3200 km/s which would give us many hours of warning. I would think the grid operators would have plans to unplug the transformers for such an event. Am I missing something?
Big plugs!
I know its “not nice” of me..
but:-)
gee i would love the mobile phone sats to go down a while
the Twitterers would go into panic mode, and all the kids who cant live without it glued to ears or fingers..
too fun!
Thank-you for the most excellent explanation of cold’s effect on plants. Like Man, plants have been dealing with cold temps for a long time. The extreme measures taken by plants to survive cold must take a heavy toll on eventual plant yield and growth, even if temperatures warm immediately after. GK
robr says:
May 8, 2012 at 9:05 pm
There is the little issue of implementing, what, a global power grid shutdown? While there is advance knowledge of a CME heading this way, there are several cases where it misses Earth. People have enough trouble handling evacuations for Cat 5 hurricanes and the disruption they cause, I doubt there’d be much tolerance for blown solar storm forecasts.
OTOH, the partial grid failure in Canada in 1989 or so happened in 90 seconds.
From a discussion with someone at ISO New England after a talk on the problems, I see it as more of a concern than I had before (note the 90 seconds), but also that grid operators take it more seriously than I thought they did.
Still, Carrington events are very rare. I confidently predict this sunspot will pass with nothing more than a chance of mid latitude aurorae.
Back in the mid 1980s, as a teen in southern Ohio, I saw the Aurora Borealis. That was at about 39N — is there any place that I could look to try to figure out what caused it to be visible that far south?
(We tried calling one of the local TV stations to see if they knew. During their 11pm broadcast, they mentioned that some people in Kentucky had phoned in a UFO report.)
The US has the capability to make power transformers. Look at http://www.geindustrial.com/publibrary/checkout/Power-Xfmr?TNR=Brochures|Power-Xfmr|generic
Brian J. Baker says:
The US has the capability to make power transformers.
Just wondering how they would make them if there’s no power?
Ric Werme says:
May 8, 2012 at 5:42 pm
I saw a total solar eclipse years ago in Cork, Ireland. It was very exciting! we had clear skies, it was bright and sunny then the moon began crossing the path of the sun and it went dark, I remember the shadows too, it was a very eerie experience.
RE: gringojay says:
May 8, 2012 at 11:10 pm
Wow! And thanks! All I knew was that plants turn purple when chilled. Now I can study the chemestry.
I forgot about tomato plants turning purple, when you put them in the garden too early. I’ve seen that many times.
I suppose it varies from plant to plant, but is “turning-purple” a survival skill, or merely a sign of stress? Can plants recover, or should they be dug out and replaced by greener seedlings?
It may pay to know about such things, if the “quiet sun” makes gardening in the north a high risk venture.
Thanks again.
Got a pretty good pic of the spots yesterday through an 8″ SCT. Is it possible to upload it? Tried to cpoy and paste but that does not work. Not much change from those photos posted above.
Ric Werme says:
May 9, 2012 at 7:28 am
” I confidently predict this sunspot will pass with nothing more than a chance of mid latitude aurorae.”
============
The odds are in your favor, but must you tempt Sol like this 🙂
Anything yet? Wondering about that Russian airliner demo in Indo.
Caleb,
Cold snap stress essentially let’s too many Iron ions behave “badly” resulting in hydroxls cleaving off from normal plant compounds. Then those loose hydroxyls can oxidize internal plant cell molecules. If the stressing is excessive (for that plant variety) the hydroxyls can even “break” DNA strands. It is a byproduct of broken DNA that, as a “new” molecule, is capable of instigating cascades that can actually cause the stress challenged cell to die. The plant cell’s response of making anthocyanins is it’s way of trying to divert that cell’s move toward death. The anthocyanin protects by instigating the hydrolizing of that “broken” DNA metabolite & thus alter that dangerous byproduct into a tweaked metabolite which lets the cell survive.
Saving cold stressed plants is hit or miss, so can only suggest a strategy to try. If rush to remedial feed them really high Phosphorus then the Iron will become excessively held making for weak cell walls; and force feeding high Nitrogen provokes thin cell walls which opens plant to a insect/viral/fungal attack.
Epsom salts has Magnesium that facilitates Calcium ion uptake by plant & may ideally best help you to resurrect a cold stressed plant. Calcium is what promotes NEW cell division, cell elongation & sustains normal membrane permiability. In fact the % plant tissue concentration of Calcium ideally increases as a plant matures; while it acts to reduce competitions between Sodium & Potassium, as well as reducing conflict between Magnesium & Potassium.
Calcium increases the uptake of Potassium & then it will be the Potassium that gives you a stronger plant that might go on to thrive. Cold stressed plants more readily recirculate downward the 20% of Potassium stored in the xylem upstream when plant organic acid anions travel down the phloem carrying along Potassium. Those organic acid anions efflux at the root which favors other cations uptake than Potassium, so aerial part of plant not getting strong.
3 tablespoons dry Epsom salt mixed into 1 quart (1 Lt) water makes a basic stock & when ready to use add 1 fluid teaspoon (5 mL) of the Epsom salt stock to a gallon (4Lt) of water to make a safe dilution. Any too high % of dissolved solids makes it difficult for plant to absorb minerals. (Even normal plants weekly benefit from 1 tablespoon Epsom salts/gallon water feeding; while sprayed on fruit buds helps holds them on plant.)
Eggshells (or just sea shells) can give you the Calcium to use. Soak 50 gr. shells in 1 Lt 5% white vinegar for 24 hours, gently simmer (nonreactive vessel) for 1 hour, filter out solids, & to the liquid part add water to bring the volume back up to what started with. That is calcium acetate with a content of 15 – 16.7 grams Calcium per Lt. A good rate of Calcium to add to the watering solution (such as the diluted Epsom salt stock) at time of use is 400 – 1,600 mg. per gallon (100 – 400 mg/Lt).
Attaining a uniform soil moisture frequently with lots of water flushes mineral salts build up, facilitates Calcium dissolving & getting to needy leaves (if soil was previously loaded with ammoniacal NH4 Nitrogen that competes with Calcium uptake). Soon you will be want to supply trace minerals (like seaweed/kelp powder at 1 oz. per 30 gallon water, or alfalfa pellets at 50 lb. per 5 gallon fermented) & then when plant seems stabilized low total dissolved solids of N-P-K fertilization.
edit my own post for accuracy:
It is hydroxyl radicals oxidizing a nucleotide acid base that forms a metabolite capable of breaking DNA double strand & protective anthocyanins hydrolyze that metabolite into another form that is not going to break DNA.
The idea is that there is so much more electric circuitry now, and we are so dependent on it, that the impact would be magnified.
@Caleb:
Purple stuff:
http://en.wikipedia.org/wiki/Anthocyanin
good antioxidant.
@DC Intertie topic:
http://en.wikipedia.org/wiki/Pacific_DC_Intertie
High voltage. Specialized semiconductors. I’d expect it to fry the semiconductors in a Carrington Event.
@Vukcevic:
Nice, very nice…
@Robr:
The belief is that the automated disconnects will protect the system. During the Quebec outage that was largely true, though some areas did have damage, it was managed.
Don’t expect anyone to shut stuff down prior to some kinds of transients starting to cause issues. In major events, things will start to shut down prior to the worst of it.
Also remember that one side of the planet is facing away from the CME when it hits… Effects will likely not be equal globally.
@TonyG:
There are thousands of very large diesel generators all over the place. I’ve rented a few to power a building to bring up a data center when PG&E was running late. If that’s not enough, every train engine is a diesel electric generator, as are many navy ships. In a real emergency, folks can make power.
@All:
A little thing to worry about:
Even if the grid does not go down, think the noise and spikes on the wires might fry a lot of the electronic ballasts on things like CFL and LED light bulbs?
I have a small stock of good old incandescent bulbs “just in case”…. MUCH more resistant to crap on the wires…
E.M.Smith says:
“Don’t expect anyone to shut stuff down prior to some kinds of transients starting to cause issues. In major events, things will start to shut down prior to the worst of it.”
Yes, expect utilities to coordinate with ISO/RTO, state, (and possibly) federal officials on a controlled (yet likely limited) take down of the electric grids. In fact, discussions have already occurred for the more recent CMEs.
“Even if the grid does not go down, think the noise and spikes on the wires might fry a lot of the electronic ballasts on things like CFL and LED bulbs?”
No, the ballasts on these lighting systems will not be fried. Geomagnetically-induced current (GIC) impacts are largely focused on extra high voltage systems (i.e., transmission above 230 kV) that traverse extended distances. The handful of centimeters associated with the circuitry of a distribution system CFL or LED bulb are de minimus and irrelevant to GICs. And any “noise and spikes” on the [high voltage] lines would be attenuated (intentionally and unintentionally) long before it reached the distribution system’s secondaries that actually supply electricity to the consumers.
Here’s a relatively reasonable presentation of GICs and their impact on the electric grid, although it has a bit of an alarmist edge because it presumes that response actions will not accommodate special conditions (e.g., waiving environmental contaminant requirements for oil-filled equipment) associated with a regional or national emergency – http://www.fas.org/irp/eprint/geomag.pdf
vukcevic says:
May 8, 2012 at 2:52 pm
These fire crackers may be doing more than we know or suspect.
http://www.vukcevic.talktalk.net/TMC.htm
note correlation, spectral power distribution and then very odd percentage disparity between the incoming TSI and what is happening some 3000km below the Earth’s surface. Our planet has many amazing secrets.
;———————-
Regarding the correlation between TSI and change in B_z, I would argue you probably should be looking upwards toward the electromagnetic tides in ionosphere instead of downwards toward the center of the Earth.
I view the Earth’s magnetic poles moving independently and the Earth’s magnetic field having a obiquity or tilt different from the rotational tilt of the Earth at the surface as surface effects.
Also, the spectral power distribution is a function of frequency – as the name implies. Your power spectrum has time in years as the independent variable.
gringojay says:
May 9, 2012 at 5:51 pm
—
Thank you for information on calcium – and dosage of epsom salts, I’d just yesterday brought out the bucket of it but hadn’t got around to watering..
Brian J. Baker says:
May 9, 2012 at 10:04 am
That link didn’t survive WordPress’s conversion well, this link may do better.
Curiously, enough, the link displays a brochure from Prolec GE, apparently a GE owned business with world headquarters in Monterrey, Mexico.
So apparently Mexico has the capability to make power transformers.
Good find though, the brochure describes transformers that a large generation facility would need.
G.Karst & Global Cooling Watchers,
Cold snap to plants causes transcription factor DAM (dormancy associated MADS-box group) gene to undergo chromatin alteration. The plant accrues more numbers of these transcriptors depending on cold duration (particular DAM groups play out differently). DAM action is quite readily induced in meristem growth tips, less so in leaves in buds impact usually needs longer duration of cold to activate.
Induction of DAM seems to upregulate the phenyl propanoid pathway which, via certain steps, is integral to making mono-lignal molecules. These go on to polymerize as lignan to lay up on a cell wall for bulk & also participate in differentiation of xylem cell in the plant’s circulatory system. So, a non-cold tolerant plant will basicly get sclerotic if just those early pathway steps go on (think how mature annual plants get more woody as cold comes),
Anthocyanins are a divergent phenylpropanoid pathway step that temporarily diminishes phenylypropane resources from lignan production. In plants which turn purple, due to cold induced DAM transcriptors, there’s been a push upregulating steps all the way to make precursors into anthocyanins. This redirection of molecular resources stalls the cold stressed plant’s rush to become sclerotic & give it time to try to survive stress. The sweet potato’s purple is an anthocyanin & that tuber is not woody.
gringojay:
I appreciate your descriptions of the cold weather responses. My plant physiology experience reached merely to photosynthesis in high school and Scientific American, as things were still being nailed down.
I’d call your contributions in depth responses, but they’d really do better as the introduction to chapters of a plant physiology textbook. Still, useful information for the “extreme gardener.”
I have a question about the other end of the season. Simply put, “What makes maple trees turn red in the fall?” The more detailed question/observation is that some perfect season resulted a tree between my neighbor and me becoming so red in 2001 it saturated the film – see http://wermenh.com/images/autumn_tree.jpg
It’s never done as well since then, possibly due to issues like black spot mold, dry Augusts, and few frosts in September. I do remember a Science News article that referred to the leaves going out of their way to make protective anthocyanins, instead of the line I always heard growing up that the color was always there, but chlorophyll was blocking it.
So, the real question is “What conditions lead to glorious fall foliage seasons and how can I predict them?”
Today, AR1476 has the Earth directly in its sights. 75% chance of an M class event and 20% for an X class in the next 24hrs. Time will tell.
http://www.swpc.noaa.gov/alerts/warnings_timeline.html
Ric Werme,
As leaf chlorophyll degrades the tree strives to retake nitrogen, but without chlorophyll working the light striking leaf can incite damage. There are minerals the tree also tries to pull back in & those ions on the move can instigate radicals the anthocyanin antioxidant treats. A red colored leaf is poorly picked up by insect photoreceptors & thus red leaves help mask those still resource holding leaves that have lost chlorophyll & are becoming colored insect photoreceptor attractive yellow.
Your pictured tree just had a great season. It grew with so many resources it could dedicate energy to anthocyanin production and maximized internal recycling. Stand alone trees apparently make more anthocyanins because need the “camo”/screen more due to being so exposed. Sorry can’t parse the factors for fall splendor.