A Forbush decrease is a rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection (CME). It occurs due to the magnetic field of the plasma solar wind sweeping some of the galactic cosmic rays away from Earth.
Well we have that going on in a dramatic way right now, it’s been going on since late yesterday. See the Oulu neutron monitor (a proxy for cosmic rays) graph:
That’s a screencap, you can monitor it live on the WUWT solar page here.
The term Forbush decrease was named after the American physicist Scott E. Forbush, who studied cosmic rays in the 1930s and 1940s.
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It’s all for Bush?
(Sorry, couldn’t resist)
What we really need is to observe cloud cover change over oceanic regions where aerosols from land are mostly absent.
Vuk,
http://sciencebits.com/calorimeter
I have a different view.
Assuming this Forbush decrease leads to less cloud cover. But it doesn’t stop evaporation does it? If anything, less cloud cover should lead to more evaporation.
So now we have lots of H2O in the atmosphere which hasn’t condensed into clouds.
The effects of this solar flare will subside in a few days. Then what? I would expect a sudden increase in cloud cover due to the extra water molecules in the atmosphere leading to some extreme weather by the end of the month.
Get your snow shovels ready in the Northern Hemisphere while I’ll get ready for some more floods here in Queensland.
I wouldn’t expect a rise in temp because of all the coincident melting snow and evaporation, but maybe a slight rise in sea surface temp and humidity.
jorgekafkazar says:
February 19, 2011 at 12:36 pm
Max Hugoson says: “…What category of science does this come under if Svensmark’s “prediction” comes through?”
“data?”
If the predicted events occur then Svensmark will have PREDICTED data points from the combination of a set of PHYSICAL HYPOTHESES and INITIAL CONDITIONS which CONFIRM (to some degree, of course) the physical hypotheses. So, you now have data points that have been predicted and that serve to confirm hypotheses. For the first time in climate science, beyond the CO2 hypotheses from the 19th century, you have A GENUINE CONFIRMATION OF A GENUINE PREDICTION. The data points count as both prediction and confirmation.
IMHO, If this sort of this thing (cosmic-ray-reduction) has any effect at all on cloud-cover, this short-lived anomaly will not be able to be detected. The values will bounce back up just as quickly as they dropped, and any effect will be lost in the noise.
Anecdotal evidence. Here in a remote corner of Indonesia, the clouds vanished a few days ago, the rains (it’s the wet season) have suddenly stopped, and it’s much hotter exercising outside. Humidity has dropped, dramatically, and the surf has gotten dangerous (don’t ask me how that fits, it’s not windy either). The difference from the last month is absolutely remarkable. Note, this is one single personal observation and it is not outside normal weather variation. But go Svensmark!
Anyone else anywhere else?
steven mosher said on February 19, 2011 at 1:34 pm
You guys realize that the cloud data (amount of cloud cover) DEPENDS upon radiative transfer equations. That is, the raw sensor inputs are ‘transformed’ by a physics model of radiative transfer. the same physics that gets used in GCMs.
Makes for an interesting epistemological quandry.
UNQUOTE
Steve – does the fact that a certain accepted law of physics is used in a certain computer program prove that the output of that program will be the revealed truth?
OR does
CORRECT LAW of PHYSICS + A LOT of GARBAGE still EQUAL GARBAGE OUT?
particularly if the inputs are manipulated in ways that do not, completely, mimic reality?
PandR says:
February 19, 2011 at 6:28 pm
It’s worse than anectodal, it’s drawing a long bow whilst clutching at straws.
Tropical cyclones to the south and south west of you would explain most of your observations.
But fear not, your wet season will be back with a vengeance soon 🙂
don’t forget though, the GCR background is not constant – it varies depending on our location in the galaxy and increases as we pass through the galactic plane and decreases as we move away from it. And even at the speed of light these effects have a lag – so don’t just expect to see a drop in cloud formation overnight
PandR says:
February 19, 2011 at 6:28 pm
Anecdotal evidence. Here in a remote corner of Indonesia, the clouds vanished a few days ago, the rains (it’s the wet season) have suddenly stopped, and it’s much hotter exercising outside. Humidity has dropped, dramatically, and the surf has gotten dangerous (don’t ask me how that fits, it’s not windy either). The difference from the last month is absolutely remarkable. Note, this is one single personal observation and it is not outside normal weather variation. But go Svensmark!
Anyone else anywhere else?
======================================
Just another anecdote, but here in Oklahoma we had blizzards each of the two first weeks of February. IIRC we had a new statewide record low of -31 around the 9th. Then this week (starting with a high of 70F on Sunday, the 13th), we ended up with a new record high temp (81F or thereabouts) on the 16th – just one week after the new record low was logged!
According to the graphs I have saved off of Spaceweather.com, the first M-level solar flares were on 2-8-11 and 2-9-11 after a long period of low levels. Then we had those X-level flares. Some of those emissions take about 3 days to reach Earth, right? Just sayin’….
While we’re on the subject of anecdotal evidence, suddenly the skies in Kamloops BC have turned clear and it was a beautiful sunny day today albeit cold with my jeep thermometer reading 12 F when I left for work this morning. After despairing of seeing any auroras with seemingly endless overcast days, finally it’s clear enough that I can head outside now and see the effects of the recent CME’s on the earth’s atmosphere which I assume will be visible at a latitude of 50 N.
I know, the clearing of the skies is probably pure coincidence, but it feels like Gaia is trying to tell the people of the world to ignore CO2 and look for the cosmic influences on climate which dwarf anything that we’re capable of now. Another shot of Jagermeister and I’ll be adequately prepared for winter stargazing.
Boris,
Ms Gaia is right as always. Hoist that shot of Jagermeister, and carry on.
You da man!
I predict a corresponding decrease in volcanic plumes coming. Confusing the whole deal.
Can someone explain this to me?
The neutrons as said is a proxy. What is their origin? The Sun? Secondary radiation due to direct nuclear hits by primary cosmic particles?They have a relatively short half life, but in spite of time compression most of them might have decayed into protons and electrons (mainly) during their travel from some distant cataclysm. So hardly they have a direct cosmic origin?
Neutrons don’t cause much ionisation either? Heavy ionized particles – mainly alpha particles but also protons have a high Linear Energy Transfer – LET, leaving heavy traces of ionisation and secondary radiation that might trigger precipitation in water vapour, that is supposed to be the mechanism of cloud formation.
AusieDan
So you accept Radiative transfer equations?
OK, looks like folks are being anecdotal… so….
Here on the Loony Left Coast of California we’ve had more or less steady rain for days. I’m sick of it. So today it’s just stopped. We’ll see what tomorrow brings, but it’s been a while since I’ve stepped out the front door and not had rain on my head. I like it 😉
FWIW, I’d also expect that a day or three after the Forbush even ends, we get a boat load of rain again…
Oh, and a couple of days ago the fire alarm at school ‘went off’ without anyone activating it. The fire trucks got sent home with a “not us”… there were also a few more computer problems than usual. Looks to me it was just about the start day of the event.
Brian H
and
aaron
I started looking into the climate events less than two years ago, and found important correlation as shown here:
http://www.vukcevic.talktalk.net/GeoMagField.gif
Considering that the cosmic rays impact is greatest at the magnetic poles, and it is modulated by the strength of geomagnetic field, in far greater measure than the sunspot cycles (100:1 magnetic field strength ratio), than the Svensmark’s hypothesis would be an appropriate solution to my correlation.
However a closer look at the polar areas shows that albedo in the winter doesn’t matter much, and clouds, as vapour is GH gas, would actually work in opposite direction to the Sv’s idea. In the summer months ice covered area has greater albedo than clouds, so clouds effect is only albedo-efficient over the ice/snow free areas.
Albedo effect is greatest in the tropical ad subtropical areas, but there the neutron count impacts drop to about 30% of the polar, e.g. 1500+ against 4700.
Other factor to be taken into account is that the day’s cloud albedo is countered by the night’s clouds GH gas effect.
Calculations of the cloudiness change of + – 1.5% – 2% are well within the margin of error.
Sceptics’ task is to look for a viable correlation and mechanism, rather than keep fingers crossed, and with a bit of luck Svensmark’s effect would eventually solve everything.
It would be a great boost for my other geomagnetic correlations
http://www.vukcevic.talktalk.net/NFC1.htm
http://www.vukcevic.talktalk.net/LFC20.htm
but I am not optimistic, just a realist.
DirkH says:
February 19, 2011 at 4:39 pm
Nellie.
And for all the reports from the South Pacific in this thread. Thanks!
(I couldn’t resist either)
Correction to the above: equatorial high count 1500+ /min, polar high count 4700 x 100/hour or 7600/ min, hence equatorial count is only 20% (not 30%) of the polar count.
Current count:
http://neutronm.bartol.udel.edu/~pyle/TheThPlot.gif
I would like to read what Piers Corbyn has to say on the matter along with a forecast. Observations of the real world are so much better than computer models. Is this is the real CLOUD experiment?
Here’s some nice backround on Forbush:
—–
E.M.Smith says:
February 20, 2011 at 3:02 am
“OK, looks like folks are being anecdotal… so….Here on the Loony Left Coast of California we’ve had more or less steady rain for days. I’m sick of it. So today it’s just stopped. ”
Well, anecdotally on the other side of the mountains the precipitation just showed up, and we will get dumped on here in Michigan. An anecdotal observation would be that cosmic rays cause water to tend to precipitate immediately, on costal areas like the U.K., west coast U.S., Pakistan, Australia, to name a few recent flood zones. During Forbush decreases, or during a solar maximum, the water stays aloft and precipitation is evenly distributed. At solar min, cooling is caused by drying of the atmosphere causing reduced greenhouse effect, as well as several other effects (TSI, AO, ozone, ???).
Forbush has not done much for Europe:
http://www.sat24.com/