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 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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Member Since: August 2, 2010 Posts: 21 Comments: 9656
Quoting VFJ:
anybody see drak lately?


No, I think he had a premonition! LOL!
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Quoting kwgirl:
LOL and I panicked when I didn't see my ignore or hide buttons.


The way things are going in here today, I'd panic too...I amnestied a couple of people from my list and see what happened...they went back on pretty quick, but yikes!
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Quoting hydrus:
Large system off of the Philippines..
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Large system off of the Philippines..
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SMDH.If you all ignore "HIM" and keep "HIM" out of your post he will go away.
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Quoting 1911maker:
Comic......

Plutonium is 1000x less toxic than Botox (and other science facts)

http://www.smartplanet.com/technology/blog/scienc e-scope/plutonium-is-1000x-less-toxic-than-botox-a nd-other-science-facts/6535/
Link

Please do not blame me, some one asked for humor. :)


Let's inject 10mg of plutonium into her forehead and see what happens...
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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:
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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
I feel like the U.S is in danger this year as well.I will do a blog with my full thoughts however in May.
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Status and History day by day, of the Nuclear Reactors at the Fukushima Daiichi Power Plant
None of the six reactors at the plant have operated since the earthquake. But explosions have damaged four of the buildings, and fuel in the reactors and spent fuel stored in the buildings is in danger of melting and releasing radioactive materials.

Link

Reactor 1
Outer building is damaged and it is presumed that there was a partial meltdown. Small amounts of radioactivity have been vented. Reactor has 400 fuel assemblies, the spent fuel pool has 292.

Reactor 2
Partial meltdown is presumed to have occurred. The containment vessel may have been breached and some radioactivity has vented. Reactor has 548 fuel assemblies, the spent fuel pool has 587.

Reactor 3
The reactor used uranium and plutonium, which may produce more toxic radioactivity. The spent fuel pool may have become uncovered. Reactor has 548 fuel assemblies, the spent fuel pool has 514.

Reactor 4
Spent fuel rods in a water pool may have become exposed to air, emitting radioactive gases. An explosion and fire have damaged the building. No fuel assemblies in reactor; 548 were removed for maintenance and are part of 1,479 in spent fuel pools.

Reactor 5
The reactor is shut down and the building is not damaged. But there is concern that spent fuel in the building may become exposed to air. Reactor has 548 fuel assemblies, the spent fuel pool has 826.

Reactor 6
The reactor is shut down and the building is not damaged. But there is concern that spent fuel in the building may become exposed to air. Reactor has 764 fuel assemblies, and there are 1,136 in spent fuel pools.
Member Since: August 2, 2010 Posts: 21 Comments: 9656
Quoting Floodman:


Well, I have to admit I was one of them at first blush; as more information became available the depth of the situation became a bit more clear.

The tsunami footage is more than I can bear to watch...someone posted a "Godzilla attacks nuclear plant" photoshop job the other day and I have to tell you, it was a little closer to the mark than the poster intended, I'm afraid.

That having been said, I see FloridaHeat is back as a faux JFV; interesting...I wonder who he/she is, really?


Hard to say...maybe the real JFV under a new handle? Any over/unders on how long it'll take for a permaban on good ol' VFJ? LOL!
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Quoting hurricanejunky:


Yo Flood! Top O' The Day to you...I am starting to get depressive overdose of Japan coverage. It seems like something of this magnitude can't be covered on television. The scope and depth of this tragedy is mind boggling. It's hard to watch alot of the tsunami video because it's that bad. We can only hope nothing like this chain of events happens in the U.S. Not surprised about the severity of the nuclear situation. Where are all the geniuses that accused everyone of overreacting or hyperventilating about it? Egg on their face, eh?


Well, I have to admit I was one of them at first blush; as more information became available the depth of the situation became a bit more clear.

The tsunami footage is more than I can bear to watch...someone posted a "Godzilla attacks nuclear plant" photoshop job the other day and I have to tell you, it was a little closer to the mark than the poster intended, I'm afraid.

That having been said, I see FloridaHeat is back as a faux JFV; interesting...I wonder who he/she is, really?
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Quoting hurricanejunky:
Holy batnuts...Jackhole is back...
LOL and I panicked when I didn't see my ignore or hide buttons.
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6.42am Japan acknowledged the nuclear crisis was worse than it previously stated overnight, raising the accident level to five - "an accident with wider consequences" - on the International Nuclear Event Scale (INES). The world's worst nuclear disaster, at Chernobyl in 1986, rated a seven. The New York Times is keeping account of the status of each the nuclear reactors.
Member Since: August 2, 2010 Posts: 21 Comments: 9656
Quoting hurricanejunky:


Your E-Harmony match report came back...Glenn Beck is your soul mate...have a great weekend!


I don't care who you are, that was funny.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting MagicFan:
This blog is going banana's today. I really hope we get a Tropical Cyclone in May so people have something to track.


ya think, YES;)
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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.
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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
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Don't be fooled by this nice weather now.Becuase by tomorrow it will be a just a recent memorie.The GFS is forecasting snow in the east next week.March Madness still continues...
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Quoting 1911maker:
Kwgirl, thanks for help, some other folks sent mail also. The issue is the sytem will not let me delete the "not photo" and it will also not let me select another as my avatar.

I supect I need admin on this one.

Thanks all for help, even if I am not "saved" quite yet............
Try clicking on the red x. I tried it on yours and it let me. Strange. I also have to quote someone twice before I can get it to stay on the post.
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into Madagascar

Member Since: August 2, 2010 Posts: 21 Comments: 9656
I know everyone is star strucked but does anybody want to talk about the nice/above average weather in the east.And about the upcoming hurricane season.
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Gotta love how so many, but yet so few like to still perch your chest out after getting your butts kicked in the last election! Then you wonder why your not tolerated by the majority and your way of thinking!
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JFV, are you gonna behave this time? What am I saying????
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and move on...
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Member Since: August 2, 2010 Posts: 21 Comments: 9656
Quoting cat5hurricane:
LOL
Play the tragedy music.I'm not even gunna....
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OMG!!!!!
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Kwgirl, thanks for help, some other folks sent mail also. The issue is the sytem will not let me delete the "not photo" and it will also not let me select another as my avatar.

I supect I need admin on this one.

Thanks all for help, even if I am not "saved" quite yet............
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Quoting Levi32:


Tropical waves do not form in the Caribbean. They form over Africa, and are actually aided by wind shear, not hindered.

But yes, wind shear is well below normal in the tropical Atlantic.



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" ...
Member Since: August 2, 2010 Posts: 21 Comments: 9656
Quoting Floodman:



Muahahahaha!


Yo Flood! Top O' The Day to you...I am starting to get depressive overdose of Japan coverage. It seems like something of this magnitude can't be covered on television. The scope and depth of this tragedy is mind boggling. It's hard to watch alot of the tsunami video because it's that bad. We can only hope nothing like this chain of events happens in the U.S. Not surprised about the severity of the nuclear situation. Where are all the geniuses that accused everyone of overreacting or hyperventilating about it? Egg on their face, eh?
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Quoting hurricanejunky:


I didn't think it would be an insult to him...oh well...maybe I'm wrong?
It was more of a look out post.As in if you make a wrong move then you'll be banned with him.I know some bloggers that were banned with the person they were arguing with.
Quoting CybrTeddy:


The higher than normal SST's and well below average wind shear tells me we have a higher than normal chance of a TS in May, and an active July.
An active July is certainly in the cards.A matter of fact I wouldn't at all be surprised if a major hurricane formed in July.And also in the last two nutreal years a major hurricane has formed in that month.
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Well did I get lost trying to research how to change your avatar. Click on your picture, or non-picture. It will take you to a screen and near the bottom right hand side should be a button to edit picture. then you can upload another picture you want for your avatar. You should have something saved on your computer you want to upload to WU.
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Even though 2011 is not as warm as 2010 was.The sst profile is similar to that of 2005's.And you all should look at the ominous Gulf stream,and the eddie in the gulf.The ingridents are coming together.But the question is....will the storms this season take advantadge of them.Hopefully not.Let's continue to cross our fingers.
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Quoting hurricanejunky:


Your E-Harmony match report came back...Glenn Beck is your soul mate...have a great weekend!



Muahahahaha!
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        Does anyone know where I can find a blog that discusses religion,Agw,science,politics,nuclear science,and last but not least tropical weather that has less bickering than this one?



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Quoting washingtonian115:
I like weather jokes,and celeberty jokes. This certainly spells trouble this up coming season.I wonder how the 2011 hurricane map will look like once november comes...


The higher than normal SST's and well below average wind shear tells me we have a higher than normal chance of a TS in May, and an active July.
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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.