Rain in Japan threatens to contaminate ground with radioactivity
A low pressure system is located over Japan near Tokyo today, and the counterclockwise flow of air around this low is bringing easterly winds over the stricken Fukushima Daiichi nuclear plant, which lies to the north-northeast of Tokyo. These easterly winds are blowing radioactivity inland over Japan. As the low tracks northeastward along the coast of Japan today, winds at the Fukushima Daiichi nuclear plant will gradually shift to northeast and then northwest, which will move radiation towards Tokyo for several hours, which may be long enough for some radiation to reach the city. NOAA's HYSPLIT trajectory model shows that for a release of radioactivity at 50 meters altitude beginning at 21 GMT on Monday (when an explosion at the #2 reactor was recorded), with repeat releases simulated to occur every 2 hours thereafter, the plumes will stay to the north of Tokyo (Figure 1.) However, a more detailed dispersion model being run by the Austrian weather service shows that the plumes may affect much of the Tokyo area today. Both models predict that by 18 GMT today (2pm EDT), the threat to Tokyo will be over, with more westerly winds blowing the radioactive cloud out to sea.
Figure 1. Forecast movement of a plume of radioactive plume of air emitted at 50 meters altitude at 21 UTC Monday, March 14, 2011 from the Fukushima Daiichi nuclear plant. Radioactivity is similated to be released every 2 hours thereafter, going out 24 hours. Images created using NOAA's HYSPLIT trajectory model.
As the low pressure system moves through Japan today, it will bring rain. Current radar loops from the Japan Meteorological Agency show a wide area of rain approaching Tokyo and the Fukushima nuclear plant. Rain is very efficient at removing radioactive particles from the air, and there is the threat of surface and ground water contamination where significant concentrations of radioactive material get rained out. By Wednesday, most of the rain will be gone, and predominately northwesterly winds will build in behind the departing low pressure system. This flow regime will stay in place for the remainder of the week, keeping radioactive emissions from the nuclear plant away from Tokyo, and headed out to sea at low altitudes near the surface.
Ground level releases of radioactivity are typically not able to be transported long distances in significant quantities, since much of the material settles to the ground a few kilometers from the source. If there is a major explosion with hot gases that shoots radioactivity several kilometers high, that would increase the chances for long range transport, since now the ground is farther away, and the particles that start settling out will stay in the air longer before encountering the ground. Additionally, winds are stronger away from ground, due to reduced friction and presence of the jet stream aloft. These stronger winds will transport radioactivity greater distances.
Figure 2. Seven-day forecast movement of a plume of radioactive plume of air emitted at 8am EDT (12 UTC) today at 50 meters altitude from the Fukushima Daiichi nuclear plant. Flow of air in the warm and cold conveyor belts of the low pressure system affecting Japan are expected to loft radioactivity to 4 - 5 km altitude, where it will be transported thousands of miles over the coming week. Images created using NOAA's HYSPLIT trajectory model.
One case where a ground level release might get lofted to high altitudes is when the source region is located near an approaching low pressure system (extratropical cyclone), as is the case today. On the cold side of the approaching warm front, where the Fukushima nuclear plant is located today, lies a broad band of ascending air called the "cold conveyor belt." This conveyor belt can loft surface air to an altitude of several kilometers in a day, as seen in the trajectory plot in Figure 2. In addition, the "warm sector" of a low pressure system in front of the approaching cold front features a ribbon of ascending air about 100 - 200 km wide called a "warm conveyor belt", which is also capable of lofting surface air several kilometers high in a day. However, there is often considerable precipitation in both of these conveyor belts, which will tend to remove large quantities of radiation before it can be transported long distances. There will be some radiation from Japan lofted to high altitudes today by the low pressure system affecting the region, and if the radiation manages to escape being rained out, it could potentially be transported thousands of miles over the next week. A run of the HYSPLIT model following the path of a radioactive cloud emitted at 12 UTC (8am EDT) this morning shows the radioactivity being lofted 4 - 5 km in altitude and being transported over Alaska over the coming week. After a week of transport, this cloud will be considerably diluted, and I strongly doubt the radioactivity would be harmful to human health if rain or snow were to carry it to the ground over Alaska or Canada, assuming that the radiation levels currently being advertised at ground level in Japan are correct.
Jeff Masters
Reader Comments
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WTO- good video- esp about the colander vs bowl explanation on the used fuel core water pools. I found his weak laughter at the end, imitating a fireman holding a hose, to be a bit disconcerting- ahhh...a benefit of old age "go ahead and destroy your earth, I really don't care, cause I already had my fun" ...such nonchalance
foxx- a snorky good morning to you too
Feel better soon.
---->Going to watch video.
Aqua -- bumpy night here too, hope you're feeling better, suppose snot is preferable over Hair balls
again appreciation for the information posted here -- this is been technically the best pit stop for getting updates, tech talk & explanations - I am very grateful for this community comradeship & pooling of information
that's messed up...
Wow. The high-tech solutions just keep on coming...
What's most disconcerting is that none of the plans to date--water cannon, helicopter water drop, firefighters with a snorkel truck--are intended as anything more than stopgap measures. You know, a way to keep the dam from collapsing while a more permanent solution is devised. A team of U.S.-based nuclear experts are on the way; it's hoped that all these great minds can get together and find a way to stop all the units from going into an eventual meltdown, to decommission them, to cool them off and clean them up.
But what's really bothersome to me is that after all these years of using nuclear power, apparently nobody ever thought to draw up contingency plans. What will we do if the coolant pumps fail? What will we do if there are cascading failures affecting all six reactors? So now we're in a situation where three reactors have exploded and/or burned to various degrees, and the best we can come up with is water cannon, helicopter water drops, or firefighters with a snorkel truck.
--"There's no chance of a 30' tsunami overtopping the berm and flooding the generators."
--"There's no chance of a 9.0 quake striking that close."
--"There's no chance of even two reactors acting up simultaneously."
Hello, CFLWX, are you new to the blog?
Kinda like DeepwaterHorizon, eh? Junkshot? TopHat?
Watch me pull a rabbit out my hat- -
hope ya'll enjoyed all them useless neon lights.
yvw - if you look at post 690 you can see one of the holes in the wall of no. 4 that Prof. Hippel was talking about.
Link for origonal size.
you had best tell us your old screen name or you will get tore apart right now...not a threat but the tropics aren't exactly at the top of our menu of interest right now
With the Japanese Whaling Season canceled, they have quite a few water cannons available for use.
It's a troubling situation over there. Events over the past few days show that even the slightest mishap or slowing causes big problems in a hurry.
I haven't heard reported what the actual goal is here? To eventually cool the reactors enough to go in and make repairs?
I'm thinking the same thing. I recognize your avatar, I just don't recall whom it was related to, though.
If I remember correctly, the handle was similar to yours and that handle predicted doom for Florida from every thunderstorm.
AH, yes, I remember now. That person who made me consider changing my entire handle to avoid being in any way related to them. That person whose blog is banned by WunderBlogAdmin.
You know, I had the same thought! :)
respect for DocMasters and the bloggers here, is my biggest concern
and if CFLWX won't give his previous handle (yet admits he had one) then he is as good as BANNED in my book
ya'll are really sweet, y'know that, right?
That would make a good song title.
Yes, and I can see all the obstacles in your way.
I can think of a lot worse songs...
"La Cucaracha"
"Macarena"
"The song that never ends"
Shall I go on?
No, I think that will do. How is everyone today?
I'm doing well this morning. Going on vacation this afternoon, so I'm in a fantabulous mood for the morning.
How about you?
Have a good time. It is good to get away sometimes. Will you check in from time to time?
Yep, have to keep an eye on the wx anyway while I'm there. (going to NOLA to be in the St. Patrick's day parade, and see some of my wife's family)
They should now be allowed to retire for life no matter how old they are.
Water hoses sound like a good idea until they can figure out some way to contain this.
Today is my first official day 'over the hill.'
I have taken the blood pressure medication the doctor prescribed.
Was thinking of that commercial, 'had Dad only taken his pill he would have saved us all a lot of grief!'
Anyway, bring in the heavy equipment imo.
The more the better.
That sounds cool. Have a lot of fun while you're there.
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