Trace radioactivity from Japan likely over the Western U.S. today

By: Dr. Jeff Masters , 2:11 PM GMT on March 18, 2011

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Traces of radioactive substances emitted by Japan's damaged Fukushima nuclear power plant will likely arrive over the Western U.S. today, carried by the prevailing west to east winds that have blown over the Pacific Ocean during the past week. Rainfall is expected over California this weekend, and it is likely that the rain will wash radioactive particles out of the air to the surface in quantities that will be detectable at several locations. I want to strongly emphasize that the radioactivity from Japan arriving over the U.S. over the next few days poses absolutely no threat to human health, and is present in only miniscule quantities. The radioactive plumes from Japan have had seven days to dilute over a 5000+ mile journey, and have been subject to deposition to the ocean due to gravity and rainfall along the way. Natural radiation is present in our environment every day, and the extra radiation from the Fukushima nuclear plant will cause much less than a 1% increase this background radiation. Radioactive particles from the Chernobyl disaster in 1986 were detected in North America ten days after that event, and caused no harmful effects. The radiation from Japan over U.S. during the next week should be at levels even lower than the Chernobyl fallout.


Figure 1. Backward trajectories for the air arriving at the surface (red line) and 300 meters altitude (blue line) in San Francisco, California on Saturday, March 19, at 11am PDT. According to the latest run of the GFS model, the air arriving in San Franciso tomorrow will have originated near the surface in northern Japan last Saturday, when radioactive emissions from the Fukushima nuclear plant began. The radioactive particles arriving in California will be in trace quantities, and will have no harmful effects on human health. Images created using NOAA's HYSPLIT trajectory model.

Radioactive plumes emitted from Japan's troubled Fukushima nuclear power plant continue to move offshore to the east over the Pacific Ocean today, thanks to predominantly west winds blowing at 5 - 15 mph. These winds are being driven by the clockwise flow of air around a surface high pressure system centered just southeast of Tokyo. As this high pressure system moves northeastwards, parallel to the Japanese coast, today through Saturday, winds will gradually shift to the southwest, keeping the radiation from the Fukushima plant blowing out to sea. As the winds shift to southwesterly, the sinking air over Japan will be replaced by rising air, and radioactive emissions will begin being lifted high in the atmosphere. Since there is less friction aloft, and the high speed winds of jet stream increase as the air moves higher in the atmosphere, this radiation will undergo long-range transport. Latest trajectory runs using NOAA's HYSPLIT model (Figures 2 - 4) show that radioactivity emitted today could wind up over Alaska after five days, and radioactive particles emitted on Saturday could make it to California by late next week. I've made trajectory plots for the next three days assuming two possible release altitudes--a surface-based release near 10 meters, which should be the predominant altitude in the current situation, and a higher release altitude of 300 meters, which might occur if there is an explosion and major fire. However, the 5-day trek to Hawaii and California is 4000 - 5000 miles, and a tremendous amount of dispersion and dilution of the radioactive plume will occur. Given the current levels of radiation being emitted, any radioactivity reaching Hawaii or the U.S. may be difficult to detect, and will not be a threat to human health. Keep in mind also that the most dangerous radionuclide to human health in the radioactive plume--Iodine-131--has a half life of eight days, so will be reduced by at least 30% after 5 days of travel time.

Of much greater concern is the possibility of dangerous level of radiation over Japan. The next period of onshore winds that will blow radioactivity inland over Japan may occur beginning on Saturday night (U.S. time), continuing through Sunday, according to the latest run of the GFS model. The latest HYSPLIT trajectories show winds on Sunday may carry radiation from the disaster site southwards over Tokyo. A low pressure system is expected to bring considerable rain to Japan on Sunday, and this rain is likely to remove most of the radioactivity from the air where rain and radioactivity are both present. The winds associated with this low are difficult to predict at this time, since the winds will be light and variable.


Figure 2. Five-day forecast movement of plumes of radioactive air emitted at 10 meters altitude (red line) and 300 meters (blue line) at 18 UTC (2pm EDT) Friday, March 18, 2011 from the Fukushima Daiichi nuclear plant. The plumes get caught in a southwesterly flow of air in advance of an approaching low pressure system. The plume emitted near the surface (red line) stays trapped near the surface for 4 days then lifted to 4 km, but the plume emitted at 300 meters is lifted to 5 km altitude after 2 1/2 days by the rising air associated with the approaching low pressure system. Images created using NOAA's HYSPLIT trajectory model.


Figure 3. Five-day forecast movement of plumes of radioactive air emitted at 10 meters altitude (red line) and 300 meters (blue line) at 18 UTC (2pm EDT) Saturday, March 19, 2011 from the Fukushima Daiichi nuclear plant. The plumes get caught in a southwesterly flow of air in advance of an approaching low pressure system and lifted to 4 - 5 km altitude. The plumes are predicted to move over California and Mexico at high altitude. Images created using NOAA's HYSPLIT trajectory model.


Figure 4. One-day forecast movement of plumes of radioactive air emitted at 10 meters altitude (red line) and 100 meters (blue line) at 18 UTC (2pm EDT) Sunday, March 20, 2011 from the Fukushima Daiichi nuclear plant. The plumes get caught northerly winds, and the two lower altitude plumes move over Tokyo by 6 UTC on Monday, March 21. This is a low confidence forecast, as winds are expected to be light and somewhat variable on Sunday over Japan. Images created using NOAA's HYSPLIT trajectory model.

Resources
Seven-day weather forecast for Sendai near the Fukushima nuclear plant

The Austrian Weather Service is running trajectory models for Japan.

Current radar loops from the Japan Meteorological Agency

Jeff Masters

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Beautiful weather in West Palm, but no rain.

Member Since: September 10, 2007 Posts: 0 Comments: 11005
thank you, Watching...

now, do we all agree my hippo is NOT barney?
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you're welcome, Amy.

Kozo is on uTube too. (wandered off to watch)

almost as good as watching Maru the cat (thank you Aqua for that link) to release the stress of bad news.
Member Since: August 4, 2005 Posts: 26 Comments: 1190
Quoting alfabob:


Since alpha has the highest amount of energy, just in what terms can it be defined as weak? The isotopes in MOX can undergo about 9 alpha decays and 4 beta before coming stable. Your telling me that's not dangerous?


Gamma has the strongest penetration, would that not make it the strongest form of radiation?
Member Since: August 24, 2010 Posts: 19 Comments: 4357
thank you, MaryEsther

:)
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Quoting 1911maker:
Keeper... Thanks

I supect he might not trust the Gov, espeicaly the EPA. but I will let my wife make that call


Does he know the EPA was started under the Nixon administration? LOL
Member Since: July 17, 2009 Posts: 69 Comments: 25442
Quoting PalmBeachWeather:
Barney is only a figment of our imagination


No, this is Figment.

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Well, I gotta head out :o(.... got some stuff to take care of tonight...

Will look in later if time allows.

have fun, ya'll....
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Keeper... Thanks

I supect he might not trust the Gov, espeicaly the EPA. but I will let my wife make that call
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alfabob....I think I need a Bud Light......99% sure
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Baha- hey no problem. RainmanWeather's gonna be around for a long time. We'll be glad to always be your #1 weather equipment source.

:)

laterz
Member Since: August 13, 2005 Posts: 163 Comments: 25773

For the latest from MIT regarding the reactors in Japan...here is the link.

MIT NSE Nuclear Information Hub

Probably should prepare a favorite beverage because it is a fairly long read.

From the website itself...

********

Information about the incident at the Fukushima Nuclear Plants in Japan hosted by http://web.mit.edu/nse/

Maintained by the students of the Department of Nuclear Science and Engineering at MIT

********

Note: Latest updates are from today.


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Quoting 1911maker:
My wife has asked me to request the apparent impossible…..

Can any one supply any links to climate change information sights that do not immediately “scream” either LEFT or RIGHT?

She would like to have some reference points for one of her co-workers who is skeptical that the human animal is causing change, but is trying to keep an open mind.

He would honestly like to learn more, but he is conservative and the only way he might keep an open mind is if the sights provided do not proclaim to be progressive.

A climate change sight that is RIGHT leaning, and asserts that change is happening would be ideal.

A sight that only deals with climate change would be the best candidate if it is balanced.

If you have a link, and do not want to get flamed, please send it via mail.



Link
Member Since: July 15, 2006 Posts: 169 Comments: 53296
So amy is actually KOZO?
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alfabob......Thinking doesn't count
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Dr. Masters has shown us Hysplit. Does anybody know of a site that has the Hysplit results combined with the percent of radioactive isotopes remaining from the time they originated. That would be important for the plume that is expected to wrap around and come at Japan from the south east later.

One thing we learn from this is that in the event of a disaster it isn't enough for the plant to maintain integrity. The plant stood up to a very large earthquake and a tsunami only to be done in by, ironically, a lack of electricity.

While access and power are not available from the landward side of the plants I find it strange that the necessary equipment couldn't have been moved in from the sea side of the plant on barges. This goes for relief too. The old navy LSTs look like a good idea about now. (Guess I should have looked at patrap's link first)
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\
Quoting DARPAsockpuppet:


Hello Skeletor
evening
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting WatchingThisOne:
There are unconfirmed reports that the vending machines in the break room at Fukushima 1 are working again.

Still waiting on news regarding the pumps and such. I sure hope they can get something helpful going soon. The silence concerns me a bit.

I sure hope so Watching.We need to get these pumps working fast
Member Since: Posts: Comments:
There are unconfirmed reports that the vending machines in the break room at Fukushima 1 are working again.

Still waiting on news regarding the pumps and such. I sure hope they can get something helpful going soon. The silence concerns me a bit.
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Back to a little weather....Me and my ex were stationed at Eielson AFB years ago.. He was a USAF weatherman...I looked at the temp about 2:00 pm today...It was minus 11 degrees...As they say in Alaska......Summer's coming?
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thank you, aqua...

:)
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baaaa-rny
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My head hurts.....I thought it was Barney all of this time
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Quoting DARPAsockpuppet:
Mark the last 10 posts under W.G.A.S.

hello puppet
Member Since: July 15, 2006 Posts: 169 Comments: 53296
This is hurting my face.....

Thanks for the Coke info, aquaK...

BTW, did not get a chance to get that wx station ordered in time [i.e. before I made my trip last month]. I'm hoping I can do something about that before we start the season again. I'd like to have it set up by the first week in May so I can have a month to get things running properly. But we shall see....
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Barney is a dinosaur. He drinks diet coke.

Amy is a purple hippo. If I had to guess? Thai tea.
Member Since: August 13, 2005 Posts: 163 Comments: 25773
My wife has asked me to request the apparent impossible…..

Can any one supply any links to climate change information sights that do not immediately “scream” either LEFT or RIGHT?

She would like to have some reference points for one of her co-workers who is skeptical that the human animal is causing change, but is trying to keep an open mind.

He would honestly like to learn more, but he is conservative and the only way he might keep an open mind is if the sights provided do not proclaim to be progressive.

A climate change sight that is RIGHT leaning, and asserts that change is happening would be ideal.

A sight that only deals with climate change would be the best candidate if it is balanced.

If you have a link, and do not want to get flamed, please send it via mail.
Member Since: Posts: Comments:
Two purple big things ? and not one a Barney?
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Quoting PalmBeachWeather:
So tell me this.......If that is not Barney...

What is the difference between "Coke Zero & Diet Coke"???


coke zero has no sugar, no caffiene.

diet coke has no sugar, but it has lotsa caffiene.

So: Diet Coke for breakfast, Coke Zero before bed.
Member Since: August 13, 2005 Posts: 163 Comments: 25773
So tell me this.......If that is not Barney...

What is the difference between "Coke Zero & Diet Coke"???
Member Since: Posts: Comments:
Quoting PalmBeachWeather:
So that is "NOT" Barney.Sure looks like a Barney


Yes it does. Looks like Barney the Hippo.
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you guys don't get out much, do you?
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So that is "NOT" Barney.Sure looks like a Barney
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my avatar is not Barney....

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Google "Barney and Friends". I just read the Wiki on the show.
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kewl, nice to be right :o)

BTW, what happened with our south ATL AOI???
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So just what the heck is "Barney" ?
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Barney is only a figment of our imagination
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Now I am confused. Purple Rain.(Prince)
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I thought Barney was a purple dinasaur.... didn't know that was supposed to be Barney in ur pic, NRAamy...
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Me and you and a dog named Boo....Sorry, showing my age
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barney is a dino...

my purple hippo is not....
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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