Weather patterns tracked by the SJSU Department of Meteorology and Climate Science
By Pat Lopes Harris, Media Relations Director
Although all data from government sources show that harmful radiation won’t reach California, the nuclear emergency in Japan raises interesting academic questions about weather patterns.
Alison Bridger, chair of the Department of Meteorology and Climate Science, created the image to the right to answer these questions visually. The diagrams show what will happen to material emitted today.
If your computer has a Shockwave player, you can view a terrific version of nearly the same information on a world map. Click on the image to the right to go directly to Professor Bridger’s website.
Here are her notes on the diagrams, which “show forecast trajectories of air parcels emitted from the location of Fukushima, Japan. The best way to picture a trajectory is to imagine a party balloon released over Fukushima and allowed to drift with the winds. Using forecast winds from weather forecast models, we can predict the path of the balloon and thus create what we call a trajectory.
“For the figures to the right, we pretend a balloon is released over Fukushima every 12 hours, and create a new trajectory every 12 hours. The different trajectories are shown in different colors. The top figure shows the horizontal drift of the balloons, generally eastward and southward. The lower figure shows the vertical motions of the parcels. So for example, a blue line on the lower plot shows the vertical motion of the parcel over the next few days, and the blue line on the upper figure shows the horizontal motion over that same time period.
“Today (March 18), high pressure is dominating the weather over northern Japan. Trajectories show that balloons released now will stay at low levels, and will remain close to the Japanese mainland. Storms predicted to pass on March 20 and March 22 will provide more lift, shooting the balloons higher into the atmosphere (up to 5000 meters, roughly three miles, according to the lower figure). These balloons would also move further eastward over the Pacific (towards the Aleutians, according to the upper figure).” #