Worried about Japanese nuclear fallout?
EDITOR’S NOTE: I have added an explanation on now to interpret the charts in a comment at the bottom of the post.
MECHANICSVILLE, Va. — I woke up with the news of the explosion at the Fukushima Daiichi nuclear plant in Okuma, Fukushima Prefecture, Japan, and cooling troubles at the nearby Fukushima Daini nuclear plant in Tomioka (also in Fukushima Prefecture).
Live feed from NHK
Archived video of first reactor explosion
So far there has only been small-scale releases of radioactive materials—not as much as had been released in the Three Mile Island incident 1979.
According to Tokyo Electric Power Co. (TEPCO), which operates the plant, the explosion at Fukushima Daiichi reactor No. 1 was a hydrogen explosion which destroyed an outer wall and collapsed the roof of the building that housed the reactor. While the reactor’s containment shell remains intact, there remains a risk of a complete meltdown—and even greater disaster.
For those of you worried about the potential for radioactive fallout reaching your homes in North America, I offer this service (until something better comes along or the crisis ends): I will generate and post surface and upper-level weather maps for you to see the pressure and wind fields across the North Pacific Ocean. These will be posted without comment, so it is up to you to find someone who can help you make sense of them.
The maps are based on surface and upper-air data downloaded from publicly available sources and generated using the weather visualization program Digital Atmosphere using its default algorithms.
Three maps will be plotted for each time: surface pressure and wind vectors, 850-mb pressure heights and wind vectors, and 500-mb pressure heights and wind vectors. The 850-mb maps capture circulation in the lower troposphere (the lowest layer of the atmosphere and the one in which almost everything we call weather occurs) and the 500-mb maps capture circulation in the middle troposphere.
All times are in Zulu—aka Greenwich Mean Time. Eastern Standard Time is five hours behind Zulu Time. (Eastern Daylight Time is four hours behind Zulu Time.)
Surface pressure and winds; Mar. 19, 2011; 1450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1150Z, Mar. 19, 2011.
850-mb pressure heights and winds; Mar. 19, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 19, 2011.
500-mb pressure heights and winds; Mar. 19, 2011; 1150Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 19, 2011.
Surface pressure and winds; Mar. 19, 2011; 0250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0250Z, Mar. 19, 2011.
850-mb pressure heights and winds; Mar. 18, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 18, 2011.
500-mb pressure heights and winds; Mar. 18, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 18, 2011.
Surface pressure and winds; Mar. 18, 2011; 2250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2250Z, Mar. 18, 2011.
Surface pressure and winds; Mar. 18, 2011; 1450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1450Z, Mar. 18, 2011.
Surface pressure and winds; Mar. 18, 2011; 1150Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1150Z, Mar. 18, 2011.
850-mb pressure heights and winds; Mar. 18, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 18, 2011.
500-mb pressure heights and winds; Mar. 18, 2011; 1150Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 18, 2011.
Surface pressure and winds; Mar. 17, 2011; 2350Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2350Z, Mar. 17, 2011.
850-mb pressure heights and winds; Mar. 17, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 17, 2011.
500-mb pressure heights and winds; Mar. 17, 2011; 2350Z
Surface pressure and winds; Mar. 17, 2011; 1450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1450Z, Mar. 17, 2011.
850-mb pressure heights and winds; Mar. 17, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 17, 2011.
500-mb pressure heights and winds; Mar. 17, 2011; 1150Z
Surface pressure and winds; Mar. 17, 2011; 0350Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0350Z, Mar. 17, 2011.
850-mb pressure heights and winds; Mar. 16, 2011; 2350Z
500-mb pressure heights and winds; Mar. 16, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 16, 2011.
Surface pressure and winds; Mar. 16, 2011; 2150Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1150Z, Mar. 16, 2011.
Surface pressure and winds; Mar. 16, 2011; 1150Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1150Z, Mar. 16, 2011.
850-mb pressure heights and winds; Mar. 16, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 16, 2011.
500-mb pressure heights and winds; Mar. 16, 2011; 1150Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 16, 2011.
Surface pressure and winds; Mar. 16, 2011; 0450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0450Z, Mar. 16, 2011.
Surface pressure and winds; Mar. 16, 2011; 0250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0250Z, Mar. 16, 2011.
Surface pressure and winds; Mar. 16, 2011; 0050Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0050Z, Mar. 16, 2011.
850-mb pressure heights and winds; Mar. 15, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 15, 2011.
500-mb pressure heights and winds; Mar. 15, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 15, 2011.
Surface pressure and winds; Mar. 15, 2011; 2250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2250Z, Mar. 15, 2011.
Surface pressure and winds; Mar. 15, 2011; 1450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1450Z, Mar. 15, 2011.
Surface pressure and winds; Mar. 15, 2011; 1250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1250Z, Mar. 15, 2011.
850-mb pressure heights and winds; Mar. 15, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 15, 2011.
500-mb pressure heights and winds; Mar. 15, 2011; 1150Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 15, 2011.
Surface pressure and winds; Mar. 15, 2011; 0250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0250Z, Mar. 15, 2011.
Surface pressure and winds; Mar. 14, 2011; 2350Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2350Z, Mar. 14, 2011.
850-mb pressure heights and winds; Mar. 14, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 14, 2011.
500-mb pressure heights and winds; Mar. 14, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 14, 2011.
Surface pressure and winds; Mar. 14, 2011; 2250Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2250Z, Mar., 14 2011.
Surface pressure and winds; Mar. 14, 2011; 0450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1150Z, Mar. 14, 2011.
850-mb pressure heights and winds; Mar. 13, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 14, 2011.
500-mb pressure heights and winds; Mar. 13, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 14, 2011.
Surface pressure and winds; Mar. 14, 2011; 0450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0450Z, Mar. 14, 2011.
Surface pressure and winds; Mar. 14, 2011; 0150Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 0150Z, Mar. 14, 2011.
850-mb pressure heights and winds; Mar. 13, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 13, 2011.
500-mb pressure heights and winds; Mar. 13, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 13, 2011.
Surface pressure and winds; Mar. 13, 2011; 2050Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2050Z, Mar. 13, 2011.
Surface pressure and winds; Mar. 13, 2011; 1650Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1650Z, Mar. 13, 2011.
Surface pressure and winds; Mar. 13, 2011; 1450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1450Z, Mar. 13, 2011.
850-mb pressure heights and winds; Mar. 13, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 13, 2011.
500-mb pressure heights and winds; Mar. 13, 2011; 1150Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 13, 2011.
Surface pressure and winds; Mar. 12, 2011; 2350Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 2350Z, Mar. 12, 2011.
850-mb pressure heights and winds; Mar. 12, 2011; 2350Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 12, 2011.
500-mb pressure heights and winds; Mar. 12, 2011; 2350Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 2350Z, Mar. 12, 2011.
Surface pressure and winds; Mar. 12, 2011; 1750Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1750Z, Mar. 12, 2011.
Surface pressure and winds; Mar. 12, 2011; 1450Z
Northern Pacific surface pressure (in millibars) and winds (speeds in knots) at 1450Z, Mar. 12, 2011.
850-mb pressure heights and winds; Mar. 12, 2011; 1150Z
Northern Pacific 850-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 12, 2011.
500-mb pressure heights and winds; Mar. 12, 2011; 1150Z
Northern Pacific 500-mb pressure heights (in meters) and winds (speeds in knots) at 1150Z, Mar. 12, 2011.
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Here’s a guide to interpreting these charts.
On each, I’ve plotted two types of data: pressure and wind speed and direction.
Pressure values are shown with isopleths — lines connecting points of equal value. On the surface maps, they show sea-level pressure (like the barometric pressure you get in your daily weather forecast). Pressure values are given in millibars (mb) using a two-digit shorthand. The two-digit numbers that begin with 9- through 7- would actually be 99x, 98x, or 97x mb of pressure. (Average sea level pressure is 1013 mb.) Two-digit numbers that begin with 0- through say 4- have 10 as a prefix, so pressures would actually be 100x through 104x mb of pressure.
On the upper-level (850 mb and 500 mb) charts, they show the elevation of the relevant pressure value in meters. On these charts, the 850-level usually lies somewhere between 1,200 meters and 1,600 meters in elevation. The 500-mb level usually lies between 5,100 meters and 5,900 meters.
Wind blows from areas of high pressure to low pressure. On a flat, non-rotating Earth, the wind direction would be perpendicular to the pressure isopleths. In the real world, rotation of the earth and friction against its surface causes an apparent deflection in the wind direction: to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This apparent deflection — the Coriolis effect — is what causes clockwise circulation around high-pressure cells in the Northern Hemisphere (counter-clockwise circulation in the Southern Hemisphere) and counter-clockwise circulation around low-pressure cells in the Northern Hemisphere (clockwise circulation in the Southern Hemisphere).
That’s the theory of wind, but other factors can influence wind direction locally, thus the wind barbs are needed. Think of the wind barbs as arrows indicating wind speed and direction. The direction of the “fletching” — the feather-like bits — of the arrows indicate the direction the wind is coming from. The length and number of the feathers indicates the wind speed. More information on how to interpret the wind barbs can be found here: http://www.hpc.ncep.noaa.gov/dailywxmap/wxsymbols.html and here: http://www.hpc.ncep.noaa.gov/dailywxmap/plottedwx.html#dd
It’s not unusual for winds to blow in one direction at the surface and a different direction aloft. Likewise, wind speeds tend to increase with elevation because the effect of friction with the Earth’s surface decreases with height.
Radioactive isotopes tend to be heavy, so if the stuff is not blasted high into the atmosphere, airborne contamination is likely to stay in East Asia. Ocean currents may carry isotopes across the North Pacific, however, so effects on aquatic life will depend on how much is spread, how far its spread, and where it eventually settles. If there’s an explosion — such as at Chernobyl — isotopes can be blown sky-high (literally) and can be transported thousands of miles by air currents.
Forget what some of the government- and industry-approved talking heads tell you: in a worst-case scenario, radioactive fallout can reach North America. Here’s a link to some modeling from the Austria’s weather service: http://www.zamg.ac.at/aktuell/index.php?seite=1&artikel=ZAMG_2011-03-15GMT08:26
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