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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Quoting tkeith:
ovah by da Huey P.


Ovah by my mama an'dem...LOL
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Quoting ILwthrfan:
Thx Floodman and Skyepony!

Reason I asked was there was an earlier article mentioning Iceland's volcano 'Baroarbunga' which recorded a swarm of 3.0-4.0 mag. earthquakes a couple of months ago. It was speculated that it could go off dwarfing the Eyjafjallajokull. When I say dwarf I don't mean to cause hysteria. It was just said that Volcano is more explosive than its cousin to the southwest, which could compose of a larger ash cloud than what was experience last year.


Also...George Carlin was the Man! Have all his Stand-ups on DVR.


You;re welcome, man! As for George, I saw him at Wash U in St Louis a couple of times and once at the Fox Theater; hioghly intelligent, incredibly irreverent and and dead on the money...
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Quoting Grothar:


My Grandpa must have known your Grandpa!


I am a grandma and gentlewoman, and it is a GREAT philosophy to live by , ....even in not so polite company.. :)
Member Since: September 16, 2010 Posts: 0 Comments: 1496
Yas indeed,,he be over bye da Huey P.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
Hey JFV, could you PLLLLLEEEEEEEAAAAAASSSSSEEEEE stop asking if radiation will reach the East Coast? They're not showing significant radiation potentially reaching the WEST COAST much less the East Coast, GOOD LORD!
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Quoting Floodman:


No, cher...you kno', from da parrish: where y'at?

Help him out here, Pat
ovah by da Huey P.
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Quoting Dodabear:


Flood, there is no polite company anymore. It died years ago.


Doda, I am in the company of the exceptions...several of you guys here are good, easy, genteel folks...the rest of you are freaking barbarians
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328. Skyepony (Mod)
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Quoting Skyepony:
nrt~ I even tried using the page address in your page translator & it won't translate for me..


You had it as German, it is French
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Doing fine Flood, lying a little low since I tried to copy an article off Yahoo and ended up posting half of yahoo on the blog the other day. Article was about company that is scaling up ten acre bio-fuel plant that uses a bacterium that requires only CO2, water and sunlight to manufacture either ethanol or diesel, depends on which genetic code they splice in.Start looking for land around coal fired power plants that no one wants. That's my tip for the year.They think they will be commercial within two years.Let's pray no pun intended the big power companies get what they deserve.And we can tell the middle east to kiss where the sun don't shine,God willing of course.
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Quoting tkeith:
Big Easy...


No, cher...you kno', from da parrish: where y'at?

Help him out here, Pat
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324. Skyepony (Mod)
Thanks ya'll..
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Quoting Floodman:


I've been here a while and it's just easier to put someone on the list...a simple **POOF!** and they're gone (until someone quotes a "cute" post)...

My grandad told me once that a gentleman never mentions politics or religion in polite company; a shame more people don't subscribe to that philosophy (including, at times, myself)


Flood, there is no polite company anymore. It died years ago.
Member Since: Posts: Comments:
Thx Floodman and Skyepony!

Reason I asked was there was an earlier article mentioning Iceland's volcano 'Baroarbunga' which recorded a swarm of 3.0-4.0 mag. earthquakes a couple of months ago. It was speculated that it could go off dwarfing the Eyjafjallajokull. When I say dwarf I don't mean to cause hysteria. It was just said that Volcano is more explosive than its cousin to the southwest, which could compose of a larger ash cloud than what was experience last year.


Also...George Carlin was the Man! Have all his Stand-ups on DVR.
Member Since: Posts: Comments:
321. Skyepony (Mod)
nrt~ I even tried using the page address in your page translator & it won't translate for me..
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Quoting Floodman:


No worries...who says you shouldn't ignore people? LOL

Where yat, t'Keith?
Big Easy...
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319. DEKRE
Quoting Skyepony:
Can anyone translate?

18 mars 2011


The simulation results by IASB-BIRA on 15 and 16 March are now completely obsolete since the situation changes hourly.
In Europe, the International Meteorological Organisation is asking the Central Institute for Meteorology and Geodynamics (Austria) to support the International Atomic Energy Agency in the calculation of the plume dispersion.
More information as well as the regularily updated results can be found at http://www.zamg.ac.at/aktuell/index.php?seite=1&a rtikel=ZAMG_2011-03-15GMT08:26, the website of this Austrian institute.
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Quoting Levi32:


Easterly shear is often beneficial, especially to tropical waves. The reason is that convection tends to form on the convergent side of the tropical wave, the eastern side. If easterly wind shear is pushing thunderstorms off to the west of the axis, more keep forming east of the axis, allowing the tropical wave to maintain a healthy signature at the surface and a full envelope of convection, which would not exist under westerly wind shear. This is an important mechanism for Cape Verde storm development. Some of the biggest Cape Verde hurricanes started out with tropical waves under easterly shear. There's a very specific satellite signature of storms that develop under those conditions.


Thanks for that Levi... Local News Meterologists usually don't have the time to explain such science...
Member Since: August 2, 2010 Posts: 21 Comments: 9874
Quoting tkeith:
page fixed...thanks Flood :)


No worries...who says you shouldn't ignore people? LOL

Where yat, t'Keith?
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Quoting Skyepony:
Can anyone translate?

18 mars 2011 - Les résultats de simulation publiés
par l'IASB-BIRA ces 15 et 16 mars sont maintenant complètement
obsolètes, car la situation change d'heure en heure.
En Europe, l'Orgnaisation Météorologique Mondiale (OMM)
a demandé à l'Institut Central pour la Météorologie et la Géodynamique
(Autriche) de soutenir l'Agence Internationale de l'Energie Atomique
(AIEA) en réalisant des calculs de dispersion du panache. Plus
d'informations, ainsi que les résultats régulièrement mis à jour de
résultats de simulation, peuvent être trouvés sur le site web de cet Institut autrichien.



March 18, 2011 - The simulation results published
IASB-BIRA these 15 and 16 March are now completely
obsolete, as the situation changes from hour to hour.
In Europe, Orgnaisation Meteorological Organization (WMO)
asked the Central Institute for Meteorology and Geodynamics
(Austria) to support the International Agency for Atomic Energy
(IAEA) by performing calculations of plume dispersion. More
information, and the results regularly updated
simulation results can be found on the website of this Austrian Institute.
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Quoting Floodman:


If you "ignore" him the blog returns to normal...LOL
page fixed...thanks Flood :)
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Quoting washingtonian115:
Some people in Florida will even be feeling this next artic blast coming up.No it won't be considerably chilly like it was in January/February but it will surley be milder.
10 day local forecast doesn't reflect an artic blast. Guess you have access to data I don't have.
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Quoting Grothar:


My Grandpa must have known your Grandpa!


You know, if the rumours about how my grandad got around are true, my grandad could have been your grandad...

Regardless, he was a great guy and taught me many things, like

Never trust a man who doesn't curse
Always drink to excess, tomorrow may never come

and most importantly:

Always let grandma have the last word
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311. Skyepony (Mod)
nrt~ That's the page that the link goes to translated. I was looking for that comment translated.
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I guess I am going to have to log out. I have no buttons and am only reading part of the text. And I have clicked compatibilty several times. I think the unwanted troll has infected us with a virus.
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Quoting sunlinepr:


Can you explain my ignorance, I thought Easterly wind shear would inhibit the formation and development of waves coming out of Africa into the Atl and then the Caribbean?? That's a local belief repeated by Weather "meteorologists" ...


Easterly shear is often beneficial, especially to tropical waves. The reason is that convection tends to form on the convergent side of the tropical wave, the eastern side. If easterly wind shear is pushing thunderstorms off to the west of the axis, more keep forming east of the axis, allowing the tropical wave to maintain a healthy signature at the surface and a full envelope of convection, which would not exist under westerly wind shear. This is an important mechanism for Cape Verde storm development. Some of the biggest Cape Verde hurricanes started out with tropical waves under easterly shear. There's a very specific satellite signature of storms that develop under those conditions.

That said, of course easterly shear that's too strong(>15 knots) can be detrimental.
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Member Since: August 2, 2010 Posts: 21 Comments: 9874
Quoting washingtonian115:
Oh great now that video messed up the blog....


If you "ignore" him the blog returns to normal...LOL
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306. Skyepony (Mod)
New run.. Looks bad for the locals around the 20th..

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Oh great now that video messed up the blog....
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Quoting Skyepony:
Can anyone translate?

18 mars 2011 - Les résultats de simulation publiés
par l'IASB-BIRA ces 15 et 16 mars sont maintenant complètement
obsolètes, car la situation change d'heure en heure.
En Europe, l'Orgnaisation Météorologique Mondiale (OMM)
a demandé à l'Institut Central pour la Météorologie et la Géodynamique
(Autriche) de soutenir l'Agence Internationale de l'Energie Atomique
(AIEA) en réalisant des calculs de dispersion du panache. Plus
d'informations, ainsi que les résultats régulièrement mis à jour de
résultats de simulation, peuvent être trouvés sur le site web de cet Institut autrichien.



Link for translated webpage.
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Quoting all4hurricanes:
I noticed hurricane gave USA a break for 2 year after 05 then again after 08, I think USA will get hammered, and for some reason I don't think a hurricane will hit New England even though they're years overdue
Great points, and to add to it Goergia and Alabama are due as well...
Goergia hasn't seen any major storms in more than 25 years...
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Quoting hurricanejunky:


I used to have a handful of people on my iggy list but took them off. The reason I don't maintain an iggy list is because then I can't click the ! or - buttons on their posts which contributes to remedying the problem.
Quoting Floodman:


I've been here a while and it's just easier to put someone on the list...a simple **POOF!** and they're gone (until someone quotes a "cute" post)...

My grandad told me once that a gentleman never mentions politics or religion in polite company; a shame more people don't subscribe to that philosophy (including, at times, myself)
The ! and - button seems to be the best darn buttonms ever inveted on this site.Floodman:When company or family friends come over we don't dare talk about who we voted for or what we belive in....In a way it seems rude...
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Quoting gordydunnot:
Floodman there you go with your scientific approach again. Can't we just believe everything would be fine with that plutonium experiment and move right along.


What, injecting 10mg of plutonium into that smarmy, unfunny Boonsri Dickinson person's forehead? Yeah, I guess you're right...I take things too seriously sometimes...LOL

What's up, gordy?
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295. Skyepony (Mod)
Can anyone translate?

18 mars 2011 - Les résultats de simulation publiés
par l'IASB-BIRA ces 15 et 16 mars sont maintenant complètement
obsolètes, car la situation change d'heure en heure.
En Europe, l'Orgnaisation Météorologique Mondiale (OMM)
a demandé à l'Institut Central pour la Météorologie et la Géodynamique
(Autriche) de soutenir l'Agence Internationale de l'Energie Atomique
(AIEA) en réalisant des calculs de dispersion du panache. Plus
d'informations, ainsi que les résultats régulièrement mis à jour de
résultats de simulation, peuvent être trouvés sur le site web de cet Institut autrichien.

Member Since: Posts: Comments:
Floodman there you go with your scientific approach again. Can't we just believe everything would be fine with that plutonium experiment and move right along.
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Quoting CybrTeddy:


I 'could' see June being somewhat active with a few invests and a named storm but I don't think June will be anything like what we experienced last year with Hurricane Alex in June.. a near-major hurricane with a 946 mb pressure in June was ridiculous.
I'd say 3 invest the most.Maybe a 40-50 mph tropical storm is reasonable.But then again I have seen some strong tropical storms in june.Like Berry,Arleane,Alberto......The thing is though is that they all formed in the gulf.And the gulf was or slightly above average.Just like this year.
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Quoting washingtonian115:
I don't have anyone on my ignore list......a matter of fact I don't have one.DirtyDog however was close to being put on.Buuuut he wasn't.I just simply skip over the post.


I've been here a while and it's just easier to put someone on the list...a simple **POOF!** and they're gone (until someone quotes a "cute" post)...

My grandad told me once that a gentleman never mentions politics or religion in polite company; a shame more people don't subscribe to that philosophy (including, at times, myself)
Member Since: Posts: Comments:
Quoting washingtonian115:
I don't have anyone on my ignore list......a matter of fact I don't have one.DirtyDog however was close to being put on.Buuuut he wasn't.I just simply skip over the post.


I used to have a handful of people on my iggy list but took them off. The reason I don't maintain an iggy list is because then I can't click the ! or - buttons on their posts which contributes to remedying the problem.
Member Since: Posts: Comments:
Since the oceans heat with summer, it is a given that we will probably have quite a number of storms. But even after they form, it is sometimes difficult to predict where they are going to impact land. This is March and as much as we like to watch the weather, it does not help when people make asinine comments about the tropical season. I don't even pretend to predict because I am not a meteorologist. Until one forms, everyone should "hold their water" so to speak.
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Quoting Floodman:


The way things are going in here today, I'd panic too...I amnestied a couple of people from my ist and see what happened...they went back on pretty quick, but yikes!
I don't have anyone on my ignore list......a matter of fact I don't have one.DirtyDog however was close to being put on.Buuuut he wasn't.I just simply skip over the post.
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Quoting HurricaneDean07:
what about June being active Teddy?
The 2011 SST's are looking sickly in the caribbean

2008 is really the only SST map that matches to this date...


The Wind Shear is very low near Florida, and throughout the southern subtropical Region...

Shear Tendency:


I 'could' see June being somewhat active with a few invests and a named storm but I don't think June will be anything like what we experienced last year with Hurricane Alex in June.. a near-major hurricane with a 946 mb pressure in June was ridiculous.
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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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