Comments
The respite from exposure to radioactive material from Japan's quake-ravaged nuclear reactors brought about by favourable sea-ward winds may not last long, according to the latest trajectory model runs by India Meteorological Department (IMD).
The winds are northwesterly-to-westerly over the island nation blowing into the sea but this is likely to be reversed as early as from Friday (March 18), according to the IMD model runs based on the US National Oceanographic and Atmospheric Administration's (NOAA) HYSPLIT trajectory model.
WIND DIRECTION
The model uses the GFS (global forecasting system) model's wind pattern to track the movement of a hypothetical release of a substance into the atmosphere.
The Director-General of IMD, Dr Ajit Tyagi, informed Business Line late on Thursday night that the winds will change to southwesterly, which would make them blow back to the stricken northeast region of Japan.
Weather Underground, a leading private forecaster, is also largely in agreement with the IMD's outlook.
OUT TO SEA
An update by Weather Underground based in the US at 7 p.m. IST on Thursday said that favourable winds blowing at 10-20 mph out of the northwest continued over Tokyo, and these winds will take radiation particles emitted by the stricken Fukushima nuclear plant immediately out to sea.
The northwesterly winds are blowing in response to the clockwise flow of air around a high pressure system approaching Japan from the southwest.
Since high pressure systems are regions of sinking air, the radiation will stay close to the ocean surface over the next day or two as the air spirals clockwise over the Pacific.
FIVE-DAY FORECAST
Five-day forecast movement of plumes of radioactive air emitted at 10 meters altitude and 300 meters early Friday morning IST from the Fukushima Daiichi nuclear plant showed plumes initially spiralling clockwise around the high pressure system to the southwest of Japan and staying near the surface.
By Saturday, though, the plumes get caught in a southwesterly flow of air in advance of an approaching low pressure system.
Ascending air lifts the plumes to high altitudes, where winds are stronger and rapid long-range transport occurs.
LOW-PRESSURE
Five-day forecast movement of plumes of radioactive air emitted at 10 meters altitude and 300 meters early Saturday morning shows plumes getting caught in a southwesterly flow of air in advance of an approaching low pressure system.
The plume emitted near the surface would stay trapped near the surface for four days before being lifted to two km.
But the plume emitted at 300 meters is lifted to five km altitude after two-and-a-half days by the rising air associated with the approaching low-pressure system.
Comments
COMMENT NOW
Comments
Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.
We have migrated to a new commenting platform. If you are already a registered user of TheHindu Businessline and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.