Photo from Open Sources Extreme Weather – Strongest With 1930s drought in the western United States, devastating flood in Pakistan in 2010 – becoming more common, says a study by scientists at the Potsdam Institute for the Study of climate change published in Proceedings of the US National Academy of Sciences. The work is mainly devoted to “blocking patterns “when hot or humid weather sets in one region for several weeks, causing drought or floods. First of all, scientists paid attention to subarctic climate. Having reviewed the statistics for the last years, researchers have concluded that extreme weather events Now occur two times more often than at the beginning of the two thousandth. “IN the last decade has been an exceptional number of extreme weather conditions, some of which have caused enormous damage society, “- said in the work. Climatologists studied the direction high-altitude jet flows – strong air currents between troposphere and lower stratosphere – in temperate latitudes of the northern hemisphere. Bends of these giant air currents reaching several thousand kilometers in length, called “meanders.” Each a separate meander is known as the atmospheric Rossby wave – a wave, which greatly affects the weather, the formation of cyclones and anticyclones. Scientists have used data accumulated for 35 years since satellites, ships, weather stations and meteorological balloons. It turned out that when high-altitude jet flows slow down, in in some regions the weather can remain one and the same for a long time and then droughts or floods begin. Just such meanders slowdown preceded abnormal heat in Russia in 2010 year. In July-August of that year, according to the Ministry of Economic Development, due to record air temperature and forest fires in Russia died on 55.8 thousand people more than in the same period of the previous of the year. “Since 2000, we have seen an accumulation of such events. When these high-altitude currents become quasi-stationary, extreme weather begins on the surface. This is especially noticeably in case of drought, “- quotes the Guardian head exploration, geophysics Dima Kumu. The growth of “blocking patterns” closely associated with rising temperatures in the Arctic due to global climate change. According to Kumu and his colleagues, there is a clear correlation – high-altitude stream flows directly depend on the difference temperatures between the poles and the equator. Since at the moment Arctic warms up faster than lower latitudes, difference temperature is rapidly declining, which is why Rossby waves slow down. The climatologist from Reading University Ted Shepard, recalled that a series of floods and storms in the UK this winter happened just when high-altitude current “stuck in one position for a long time.” However, only the correlation between extreme weather and high Arctic temperature is not enough – it should be clearly shown a clear causal relationship between temperature in the Arctic and Rossby waves, so that the public understands how disastrous The consequences are global warming. Researchers from Postdam are working in this direction, but are not sure of success enterprises. “To show a causal relationship, computer simulation is needed, but I doubt how well modern climate models can cover these effects “, – quotes the publication of Kumu. Fights the same task Oxford professor Tim Palmer. In his last year’s article in Proceedings of the US National Academy of Sciences he wrote that to recognize the connection between “blocking weather patterns” and warming of the Arctic, computer simulation is required with detailed scaling, which today has not even been invented. “At present, national climate institutes do not have sufficient computing power to simulate climate with a scale of 20 kilometers, so there’s no question of one kilometer is coming. I look forward to the day when governments do such climate prediction investments they made in finding the boson Higgs, “complained the climatologist. The connection between global warming, natural disasters, and even social conflicts this year the American research center has already indicated Military Advisory Board – Advisory Group of Retired Three – and four-star generals and admirals under the US government, convened to study the degree of threat from global warming for United States National Security. The military prejudice that increasing droughts are becoming one of the reasons for the escalation regional and ethnic conflicts in African countries, while increasing sea level threatens populations of eastern India, Bangladesh and Vietnam. According to their forecasts, in the near future we should expect more more floods, droughts and severe storms. In the official journal Pentagon – “Four Year Review of Defense Policy” – Directly linked catastrophic natural phenomena and terrorism. “These effects are threat multipliers that will only exacerbate poverty, environmental degradation, political instability and social tension, that is, all those conditions that allow flourish terrorist activities and other forms of violence, ” – they write the American military.
Arctic Time Global warming Climate Russia USA
