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 Grothar:


The Merry Mailman, now get to bed.


"He says they had no choice... says the NVA killed their old honcho when he said no, and I say all the rice is theirs. "

This one. What movie?
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting caneswatch:


What movie is it????????


The Merry Mailman, now get to bed.
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Well, I'm out for the night guys....always sleep better after a-lot-of-laughter....and beware the Supermoon...:)
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Quoting Grothar:


When it gets down to Saudi Arabia and Iran, it will be a terrible situation. This whole scenes reminds me of a Dr. Zhivago scenario. You think you are on the winning side and the tide turns and you are caught in the middle.


The question is: Are we capable of fighting in so many war fronts? Do we have the resourses? What about our internal problems?
Member Since: August 2, 2010 Posts: 21 Comments: 9693
Quoting Grothar:



We posted it at the same time.


What movie is it????????
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting caneswatch:
C'mon Grothar, so I can go to bed LOL


Nite, Canes!
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Quoting caneswatch:


Does it look like i'm fat to you LOL? And I posted a quote.



We posted it at the same time.
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C'mon Grothar, so I can go to bed LOL
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting pottery:

To say the least....
I dont like the set-up. The entire area is super-volatile right now. With a lot of energy at stake. Also shifts in ideology. Bad mix.


Very scary in many ways. We know with whom we are dealing with. But they have no changed the rules in the middle of the game. What or who, will replace them.
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Quoting Grothar:
Canes, did you fall asleep? Let us know if we were right. EYES is going to run out of movies soon. Put down your twinkie and start typing.


Does it look like i'm fat to you LOL? And I posted a quote.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
West Pacific Floaters Satellite View at Noaa has Sendai animations

Link
Member Since: August 2, 2010 Posts: 21 Comments: 9693
Quoting Grothar:


Libya is a very complicated country as you know. For him to have held control over those different tribes for so long is something to be considered. You know the old saying, pot "Whether the glass hits the stone or the stone hits the glass, it will still be bad for the glass" It will be interesting to watch.

To say the least....
I dont like the set-up. The entire area is super-volatile right now. With a lot of energy at stake. Also shifts in ideology. Bad mix.
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Quoting EYEStoSEA:


Brando at his best...along with "Streetcar Named Desire"



Stellllllllllllllllllla!!!!
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Canes, did you fall asleep? Let us know if we were right. EYES is going to run out of movies soon. Put down your twinkie and start typing.
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Quoting Grothar:


This isn't one of your Terminator movies, is it? We only do classics.


T2 is a classic.

"He says they had no choice... says the NVA killed their old honcho when he said no, and I say all the rice is theirs. "
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting Grothar:


If you remember the Wild One??????????????????


Brando at his best...along with "Streetcar Named Desire"
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Quoting EYEStoSEA:
Easy Rider..The Wild One...


If you remember the Wild One??????????????????
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Quoting sunlinepr:


That's the strongest hand to beat...
Dictatorship has full power, and is being supported by China...


When it gets down to Saudi Arabia and Iran, it will be a terrible situation. This whole scenes reminds me of a Dr. Zhivago scenario. You think you are on the winning side and the tide turns and you are caught in the middle.
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Easy Rider..The Wild One...
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Quoting caneswatch:
"Say, that's a nice bike."


This isn't one of your Terminator movies, is it? We only do classics.
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Quoting Grothar:


What movie was that line from?


What, you don't know? Neither do I.
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"Say, that's a nice bike."
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting GeoffreyWPB:


Heat


Getting a little slow there, Geoff. I answered him as soon as he posted and posted two political blogs in between. LOL
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Quoting DontAnnoyMe:


Well then, you can safely upgrade your avocado appliances to stainless.


What movie was that line from?
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Quoting Grothar:


II haven't left fingerprints since 1962.


Well then, you can safely upgrade your avocado appliances to stainless.
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Quoting pottery:

Gadaffi has not been in power for 4 decades because he is stupid....
he has been able to survive, and thrive, in the face of many actions in the past.
Going to be interesting to see who gets the best of who.


Libya is a very complicated country as you know. For him to have held control over those different tribes for so long is something to be considered. You know the old saying, pot "Whether the glass hits the stone or the stone hits the glass, it will still be bad for the glass" It will be interesting to watch.
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Quoting Grothar:


Interesting. Wonder why we don't see anything in Iran. After all, that was the first demonstration. People seem to forget what happened last year.


That's the strongest hand to beat...
Dictatorship has full power, and is being supported by China...
Member Since: August 2, 2010 Posts: 21 Comments: 9693
Quoting Grothar:



Heat, you weren't born then either. LOL


Released: 1995, Born: 1992. OWNED.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting caneswatch:
"A guy told me one time, 'Don't let yourself get attached to anything you are not willing to walk out on in 30 seconds flat if you feel the heat around the corner.'"


Heat
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Member Since: August 2, 2010 Posts: 21 Comments: 9693
Quoting caneswatch:
"A guy told me one time, 'Don't let yourself get attached to anything you are not willing to walk out on in 30 seconds flat if you feel the heat around the corner.'"

I feel sorry for that guy. And for you, if you follow that advice.
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Quoting caneswatch:
"A guy told me one time, 'Don't let yourself get attached to anything you are not willing to walk out on in 30 seconds flat if you feel the heat around the corner.'"



Heat, you weren't born then either. LOL
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Quoting Grothar:


Going to be a sticky wicket, for sure.

Gadaffi has not been in power for 4 decades because he is stupid....
he has been able to survive, and thrive, in the face of many actions in the past.
Going to be interesting to see who gets the best of who.
Member Since: Posts: Comments:
"A guy told me one time, 'Don't let yourself get attached to anything you are not willing to walk out on in 30 seconds flat if you feel the heat around the corner.'"
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting DontAnnoyMe:


Gro, you're too old to be using a computer.


I'm too old to be breathing, so what's your point? I haven't left fingerprints since 1962.
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Quoting Grothar:


I am still using IE8. Everytime I update to a new version, it changes my settings. I am still having trouble. I was told to unplug the modem for 20 seconds and it should clear the problem. It seems to have worked. I can post now, aren't you happy?


Gro, you're too old to be using a computer.
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Quoting sunlinepr:
Middle East Protests: A Country-by-Country Look
The latest reports from Times correspondents along with social media updates on the protest movements shaking countries across the Middle East and northern Africa.

Link


Interesting. Wonder why we don't see anything in Iran. After all, that was the first demonstration. People seem to forget what happened last year.
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Quoting GeoffreyWPB:


I see air support. No troops on the ground. Those wanting to get into power in Libya, al-Qaeda and the Taliban. We don't know who to trust.


Going to be a sticky wicket, for sure.
Member Since: Posts: Comments:
Middle East Protests: A Country-by-Country Look
The latest reports from Times correspondents along with social media updates on the protest movements shaking countries across the Middle East and northern Africa.

Link
Member Since: August 2, 2010 Posts: 21 Comments: 9693
Quoting pottery:

True. And based on the rationale for Libya, Yemen and Saudi could qualify. Among a lot of other places...


What surprised me was that Lebanon brought it up for a vote first. I think there was a little power play involved. I think it may have been a good move on the part of the administration to allow the region to make the first move on this one. Getting to be a very complicated situation. One must plan this carefully.
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Quoting Grothar:


How do you rememember that, you weren't even born. Scarface


Just because I wasn't born then doesn't mean I haven't seen it LOL
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Quoting caneswatch:


It was VI, where the Emperor was striking Luke with Sith Lightning. Now, another quote. Grothar, if you don't get this one......

"In this country, you gotta make the money first. Then when you get the money, you get the power. Then when you get the power, then you get the women. "


How do you rememember that, you weren't even born. Scarface
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Quoting DontAnnoyMe:


See post 577. New site, same problem. IE9 should prevent it, but you need Vista or W7 to run it.


I am still using IE8. Everytime I update to a new version, it changes my settings. I am still having trouble. I was told to unplug the modem for 20 seconds and it should clear the problem. It seems to have worked. I can post now, aren't you happy?
Member Since: Posts: Comments:
Quoting Grothar:


Star Wars V or VI dont remember


It was VI, where the Emperor was striking Luke with Sith Lightning. Now, another quote. Grothar, if you don't get this one......

"In this country, you gotta make the money first. Then when you get the money, you get the power. Then when you get the power, then you get the women. "
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting Grothar:
Things don't look good in Libya. Could be a lot of action there soon. I hope it doesn't get too out of hand. Could be a terrible situation lasting a long time.

True. And based on the rationale for Libya, Yemen and Saudi could qualify. Among a lot of other places...
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Quoting Grothar:
Things don't look good in Libya. Could be a lot of action there soon. I hope it doesn't get too out of hand. Could be a terrible situation lasting a long time.


I see air support. No troops on the ground. Those wanting to get into power in Libya, al-Qaeda and the Taliban. We don't know who to trust.
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Quoting BahaHurican:
Oh, wait. It looks like it was something freaky on the last page.

However, I thought the blog changes were supposed to get rid of that effect.... hmmm....


See post 577. New site, same problem. IE9 should prevent it, but you need Vista or W7 to run it.
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Quoting BahaHurican:
Oh, wait. It looks like it was something freaky on the last page.

However, I thought the blog changes were supposed to get rid of that effect.... hmmm....

So what's the latest on our tempeste tropical in the Reunion sector?



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Quoting EYEStoSEA:
Blazing Saddles, Cat Balou, How The West Was Won, Butch and Sundance......


Butch and Sundance, You get a C+
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Quoting GeoffreyWPB:


Return of the Jedi.


Gooooooood LOL
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting pottery:

Three blind mice ?


Leave it to you, pot. LOL
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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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