Trace radioactivity from Japan likely over the Western U.S. today
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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I'm watching CNN.
Now this is my kind of report !!!
The fire is suspected to have begun from a kitchen and immediately engulfed the series of thatched huts where the displaced Brus were sheltered. Soon after the fire broke out, fire fighters from all adjoining subdivisions rushed to the spot but could not do much in absence of adequate water and the entire camp was reduced to ashes. "The fire went beyond control immediately as the entire area is dry and windy. Worst is there is no water source near the camp to help the fire fighters. The fire service vehicles had to rush back to far off places for water and then return to the camp, which ultimately could not help douse the devastating flames", said Amitabha Kar, DG fire service. Sources from Gachhirampara-Naishingpara said the main task for the fire service, policemen and security forces is now concentrated on recovering the bodies that could still have been buried in the burning debris. "It was virtually hell fire of Biblical proportion. The flames kept on devouring huts after huts, acrid smoke billowed up and then covered the area. And then there was stench of burnt human flesh. It was a nightmare coming true even as fire service, police, camp inmates and locals stood helpless in absence of water", said Rjendra Reang, a local over telephone. He said minimum 500 huts were completely reduced to ashes.
"Besides humans, chicken and pigs could not escape the hell fire. Deaths could have been many more had not the youths had already gone for jhum (shifting) cultivation", he added. "But so many deaths in a fire incident in the region is unheard of", he added. Senior official from Agartala have left for Kanchanpur. The Brus (Reangs) had fled Mizoram on October 15, 1997 night following fierce communal riots between the Brus and Lushais (Mizos) in adjoining North Tripura. They were sheltered in six camps in Kanchanpur subdivision since then. Several tripartite talks with active involvement of the Central government failed to ensure repatriation of the Brus to their homeland as Aizwal was overtly reluctant to take them back. At a point of time there were about 45,000 displaced Brus in the six camps. At present there are about 34,000 Brus in the six camps. There was no exact official figure of Bru inmates in Gachhirampara-Naishingpara camp which caught fire on Saturday.
Only MAG 5+ displayed
HYSPLIT set at 0,30,300 meters
direct link to graphic
A simple line graph from a query off the RADNET site. A network of radiation monitoring instruments scattered across the US. This one is from the San Jose, CA site and begins on Correction: March 9th and ends with todays date.
The measurement units are in Counts Per Minute (CPM). In simple terms, same as the number of clicks on a geiger counter.
There is no simple way to convert CPM to Sieverts. It must be calculated isotope by isotope. If you dont know which isotopes, it can't be done.
Still on the simple theme, at the same rate of emission or decay, an isotope that emits more and higher energy gammas will give a higher rem/hr or Sv/hr.
So the CPM data from the RADNET site is sorted by Gamma Energy Ranges 2 through 10
Commonly accepted guidelines from folks smarter than me:
2-6, not unusual to see between 500 and 5000 and are typically transient atmospheric phenom, but can be from local radioactive elements. Local as "drifting in on the wind or rain". (?)
7-10 are typically cosmic in nature and high levels are generated from GRB's (Gamma Ray Bursts).
Doc M's current blog subject is "Trace radioactivity from Japan likely over the Western U.S. today". And that appears to be born out by the line graph. A spike in the CPM's on the 17th across Gamma Energy Ranges 2-6, followed by CPM levels remaining elevated. No day to day up/down variation as displayed prior to the 17th.
"Trace" would seem to be an accurate description-at least for San Jose! A few more of these for different locations would be required. Comparing the trend lines pre and post event is a simple approach to radiation monitoring but it may help a little.
Good. I saw Obama speak on the matter yesterday. He said this isn't a negotiable matter, and the U.S. and others will use force if Qadaiffi doesn't stop this nonsense. I think he's actually handling this well.
Obama is going to speak on this in a few minutes.
The trace amounts were found in Tokyo and the other prefectures on Friday, the first day since the government ordered nationwide daily sampling due to the nuclear crisis at the Fukushima Dai-ichi nuclear plant, the Ministry of Education, Culture, Sports, Science and Technology said.
A ministry statement said the amounts found did not exceed government safety limits. But tests on water, which for decades were only done once a year, usually show no iodine.
In any event seeing all this war-cheering saddens me, as war is the most horrific of all human endeavors, even when it is necessary.
A Department of Peace is desperately needed in these turbulent times. Please, no more war!
Records for Tokyo bear little of interest.
Last 3 days:
24 hours:
5-28 uR/hr considered "normal". So maybe a little high between the the 16th and 17th.
A US Map for Isotopes Cs 137 and Co 60 - Same units.
Accuracy/Veracity is unknown.
Link
And Denver's readings may simply be due to mineral content of the area? ( <--- WAG, not my area of expertise.)
The EPA website states there are filters in place at each RADNET site, presumably to "catch" particles which may be examined. (?)
Thanks for the good comments, bl.
:)
And atmo.
:)
Maybe just altitude catching cosmic gamma rays- add: at Denver?
Japanese Earthquake Update (19 March 2011 12:00 UTC) - Corrected
Contamination in Food Products around Fukushima
(Please note correction posted 19 March at 15:30 UTC in bold in text below. Apologies for the inconvenience.)
The Japanese Ministry of Health, Labour and Welfare has confirmed the presence of radioactive iodine contamination in food products measured in the Fukushima Prefecture, the area around the Fukushima Daiichi nuclear power plant. According to the latest data, the food products were measured from 16-18 March and indicated the presence of radioactive iodine. To date, no other radioactive isotopes have been shown to increase in the analysis of food products around Fukushima.
Though radioactive iodine has a short half-life of about 8 days and decays naturally within a matter of weeks, there is a short-term risk to human health if radioactive iodine in food is absorbed into the human body. If ingested, it can accumulate in and cause damage to the thyroid. Children and young people are particularly at risk of thyroid damage due to the ingestion of radioactive iodine.
Japanese authorities have implemented two critical measures to counter the contamination of food products by radioactive iodine. First, on 16 March, Japan's Nuclear Safety Commission recommended local authorities to instruct evacuees leaving the 20-kilometre area to ingest stable (not radioactive) iodine. As an established method of prevention, the ingestion of stable iodine can help to prevent the accumulation of radioactive iodine in the thyroid. Stable iodine pills and syrup (for children) have been made available at evacuation centres. Second, the Ministry of Health, Labour and Welfare has requested an investigation into the possible stop of sales of food products from the Fukushima Prefecture.
The IAEA has passed this information to the Food and Agricultural Organization of the United Nations (FAO) and the World Health Organization (WHO) and will continue to report on this development.
According to materials on its website, the FAO is prepared to respond upon request from the Government of Japan in the following areas:
* - assessing radioactive contamination of the agricultural environment, especially foods
* - providing technical advice and determining appropriate medium- and long-term measures for agriculture -- including soil, land, forests, crops, fisheries, animal health and welfare and food safety
* - facilitating international trade of foods, including agricultural produce
The IAEA continues to gather information on this development and will report further as events warrant.
Hmm, altitude...after all of the atmosphere above Denver, could there really be that much difference from 1 mile up and sea level? (*shrug* I dunno. Gamma absorption is not something well studied by myself, nor presented in my met curriculum, IIRC.)
LOL
From this site appears Denver is just naturally higher.
Maybe the particles from Japan are more concentrated at a higher atmospheric level. Who knows? Certainly not me, so I think I'll stop guessing.
:)
Good Saturday to you and everyone.
Rather than blocking cosmic rays, the moon itself is a powerful source of radiation, measurements show.
Irene Klotz
By Irene Klotz
Thu Dec 17, 2009 04:04 AM ET
Future lunar explorers counting on the moon to shield themselves from galactic cosmic rays might want to think about Plan B.
In a surprising discovery, scientists have found that the moon itself is a source of potentially deadly radiation.
Measurements taken by NASA's Lunar Reconnaissance Orbiter show that the number of high energy particles streaming in from space did not tail off closer to the moon's surface, as would be expected with the body of the moon blocking half the sky.
Rather, the cosmic rays created a secondary -- and potentially more dangerous -- shower by blasting particles in the lunar soil which then become radioactive.
"The moon is a source of radiation," said Boston University researcher Harlan Spence, the lead scientist for LRO's cosmic ray telescope. "This was a bit unexpected."
While the moon blocks galactic cosmic rays to some extent, the hazards posed by the secondary radiation showers counter the shielding effects, Spence said at a press conference at the American Geophysical Union meeting in San Francisco this week.
Overall, future lunar travelers face a radiation dose 30 percent to 40 percent higher than originally expected, Spence said.
Galactic cosmic rays, believed to be caused by supernova explosions, are fast-moving electrically charged electrons and atomic nuclei. They are found throughout the solar system, though their numbers are particularly high at the present time due to an unusually quiet period of solar activity.
The lack of solar magnetic fields and reduced solar wind pressure means cosmic rays have been able to more easily penetrate the inner solar system.
"We are in a period when the radiation risks are elevated, but still tolerable," Spence said, adding that the levels were about what an X-ray technician or uranium miner might normally experience in a year.
The sun cycles through periods of high and low magnetic activity about every 11 years. The next period of maximum activity, characterized by increasing number of sunspots and other disruptions of the sun's surface, is expected in 2013.
LRO found about twice as many of the highest energy cosmic rays -- those that could punch through the telescope itself -- as expected. NASA plans to use the information to design shelters and operating procedures for future human excursions to the moon.
LRO is about halfway through a one-year primary mission to scout for landing spots, find potential resources and characterize radiation and other hazards.
"The work being done in heliophysics areas is important to keeping astronauts safe," said Michael Wargo, who oversees NASA's lunar research programs. "One of the holy grails would be to be able to predict the sun's activities and give an 'all clear' on how many days astronauts could be on (spacewalks)."
Oh, and, hi nrt.
:)
Thanks, nrt.
Thanks, Pat.
All this=way beyond my brain.
"Its a Marvelous time for a Moondance"...
Hiya BFOTR
phascinating
Do you realise how many mad people we've had mascarading as world leaders?
Link
Link
my understanding is that the holes were drilled to vent hydrogen gas - not to relieve pressure. we certainly don't need any more hydrogen explosions there.
That's nuts
well I hope he's wrong
And in the meantime the French Airforce has been in action.
I wonder if they shot it down? Would not surprize me.
No way to down one of those from the ground, using a rifle....
yea, idk what took it down, but it sounded like gun fire in the background
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