Institute director Dr Ha Duyen Chau says the storms will not severely affect electrical distribution but capacity could be lowered when they occur. Electricity and oil pipeline managers should monitor information so they can take preventative measures, he says. Radio waves can also be disrupted. “Unfortunately we can’t say for sure in which months the storms will occur and although we can predict the possibility of a storm one or two days before it happens, we can only know for sure 30 minutes before it strikes,” he explains. The past two years have been quiet with just 10 storms per year, Dr Chau says. The sun’s operative cycle is 11 years. The last peak was in 2001 and the next will be in 2012. At that time, about 40-50 500-600nT storms can be expected. “We can’t exclude the possibility that it will affect Vietnam’s Vinasat-1,” he says. “We are powerless against the storms but we can understand them and thus avoid their effects.” People who suffer from heart disease, high blood pressure and psychological disorders should be aware of the storms and stay at home or travel by car during a magnetic storm. Dr Chau says that, although magnetic storms do not usually markedly affect Vietnam, it has no concrete statistics about the damage they cause. The institute has four monitoring stations-Hanoi’s Gia Lam District, Lao Cai Province’s Sapa, Da Lat in the Central Highlands and Bac Lieu in the south. Their tasks include recording the intensity, amplitude, frequency and duration of the storms. Vietnam started to study magnetic storms in 1957 but the monitoring stations were not installed until after the 500KV national grid was functioning in 1998. The institute’s statistics show the country had 40 magnetic storms in 2001 and 15 in 2006. Magnetic or geomagnetic storms are a disturbance of the earth’s magnetic field associated with charged particles generated from solar flares and sunspots. They usually last from 24 to 48 hours, but some have lasted many days. An electromagnetic storm disrupted power throughout most of Quebec, Canada, in 1989.
There will be 15-20 storms this year with an intensity of 300-400nT (nano-tesla), a unit of magnetic density.
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