Huge waves in the air stir up harsh weather

(The world has suffered from severe weather in recent years, such as the US heat wave in 2011 or in Russia in 2010 coinciding with the largest flooding ever seen in Pakistan. After these devastating individual events is a common reason that requires scientists of Potsdam Climate Research Institute (PIK).

The study will be published this week in the Proceedings of the National Academy of Sciences and shows that human-induced climate change continues to disrupt models of atmospheric flow around the Northern Hemisphere. globally through a sophisticated resonance mechanism.

An important part of the global air movement between normal Earth latitudes has a waveform wandering across the planet, oscillating between tropical regions and Arctic regions. So when they fluctuate, these waves draw warm air from tropical Europe, Russia, and the United States, and when they are down, they do the same thing with the cold air from the Arctic, by Vladimir Petoukhov. explain.

What we found is that in some recent extreme weather events the planet's magnetic waves almost freeze in their tunes for weeks. So instead of bringing cool air after bringing back the warm air before.

In fact, we observe a strong amplification of often weakly-moving components of these waves, Petoukhov said: 'Time is very important here: two or three days 30 ^o C There is no problem, but more than twenty days lead to high temperatures. Since many of the ecosystems and cities under their control have not been adapted to this, prolonged hot periods can lead to a high number of deaths, forest fires, and significant post-harvest losses. "

Unusual surface temperature is affecting the air flow.

Climate change caused by greenhouse gas emissions from burning fossil fuels does not mean uniform global warming - in the Arctic, the relative increase in temperature, amplified by the loss of Snow and ice, higher than average. This reduces the temperature difference between the North Pole and for example in Europe, but the temperature difference is a major driver of air flow. In addition, the continents are generally warmer and cooler than the oceans. These two factors are very important for our mechanism to discover that, Petoukhov said."Resulting in an unnatural pattern of mid-latitude airflow, so long-term waves of slow concept are stuck".

The authors of the study developed equations that describe wave movements in a more tropical atmosphere and show under conditions that these waves can be stagnant and gain amplification. They tested their assumptions using the daily weather data standards from the US National Center for Environmental Prediction (NCEP). In recent times, in which some extreme weather occurred, amplified traps and strong waves of specific waves - such as "the seven wave" (which has the bottom and peak covering the whole world) - was real the show. The data show an increase in the occurrence of specific atmospheric models, which are statistically significant at the 90% confidence level.

The probability of extremes increases but other factors are also good.

"Our dynamic analysis helps explain the growing number of extreme weather. It adds to previous research that has been linked to the phenomenon of climate change, but has not yet identified the mechanism behind it. " Mr. Hans Joachim Schelluberuber, director of PIK and co-author of the study said: " This is a breakthrough, although this is not at all - the physical processes suggest increasing probability. of extreme weather, but additional factors certainly play a good role, including natural transformation ". In addition, the 32-year study period in the project provides a good indication of the relevant mechanism, but is too short for clear conclusions.

However, this study has made significant progress in understanding the relationship between extreme weather and man-made climate change. Scientists were surprised how far beyond the past experience of recent extremes. New data show that the occurrence of abnormal weather is not just a linear response to the warming trend, meaning that the proposed mechanism can explain it.