The researchers will tear it away. By next year, the European Center for Medium-Range Weather Forecasts will be delivering one of the most powerful supercomputers in the world, quadrupling the capacity of its current equipment, already performing well. The machine will be located in the suburbs of Bologna, in a former tobacco factory, far from the Reading headquarters in the United Kingdom.
The art of anticipating
The supercomputer, rented for four years for a total of 70 million euros, will allow giant leaps. "The further we plan, the more we can anticipate extreme weather events"explains Florence Rabier, Director General of the European Center. The intergovernmental organization brings together 22 states, including France. Each country deals with its own national forecasts between 0 and 4 days. Beyond that, the European Center takes over.
It can be a matter of saving lives by evacuating a city or a residential area before it's too late, having the time to set off a properly sized heat plan, to shelter livestock or harvests threatened by a storm. These new forecasts will also make it possible to adapt energy consumption in case of extreme cold or heat.
Our record on the heat wave 2019 in France
Today, one-week forecasts are just right in 85% of cases. The method, proven, is always the same: scientists cut the atmosphere into small cubes, each with a value in pressure, temperature, humidity … The smaller the cubes, the more accurate are reliable. "We can know the interaction between these cubes by means of well-known fluid mechanics equations, but the closer the cutting is, the more computing power it requires"explains Sabrina Speich, from the Geosciences Department at ENS Paris.
Currently, the European Center is working on cubes of 16 km side. When scientists get the best performance from the new supercomputer, this cut could be reduced to 5 km. This is hopeful, because like the torrential rains that fell in the Aude last October, killing 15 people and causing significant damage to property, some disasters continue to strike by surprise.
Heat wave in France, 53 departments in orange vigilance
Meteorologists are already competing for the calculation hours of the European Center. To get a niche, you have to defend a project before a scientific council that allocates a time of use. In November, Sabrina Speich's team will start a new work combining oceanographic and atmospheric data to better regionalize the effects of climate change in Europe. "Everything that comes into the atmosphere comes from the oceans, which cover two-thirds of our planet. So you have to observe everything, including at sea, which is more difficult with less powerful computers "says Sabrina Speich.
The European Center for Weather Forecasting does not cover useful information in case of imminent danger. The expertise of the Center, envied around the world, is solicited for a fee by the Chinese or the Americans. The interest is strategic. "When there are great advances, the others are takers. It is not for nothing that the first medium-term forecasting model was developed to monitor the El Niño phenomenon between Peru and the United States. It was not designed for the future of the Peruvian fishermen, but to adapt the cultures to the American soil "Sabrina Speich continues.
Since its inception in 1978, the body obeys a rule parallel to Moore's Law, which predicts the exponential rise in computing power of microprocessors. The reliability of the center's forecasts has gained one day every decade. The main trends calculated for the future already suggest collective and individual economic choices in the face of global warming. Sabrina Speich takes herself as an example. "Around the Mediterranean, in France or Italy, the summers will certainly not be livable, with peaks at 50 ° C expected in 2050. I am Italian, I would have liked to buy a house in Tuscany for my retirement, but I will not do it! "
. [TagsToTranslate] weather