Dinosaurs may have died a long and painful death
"Beastly cold and significantly reduced the activity of light steel end for non-avian dinosaurs about 66 million years ago," - he says a new study at the same time points out that the mass extinction period for them was much more painful and prolonged than previously thought.
For a long time, scientists believed, or rather assumed that the dust that rose from the fall to the ground a huge asteroid that was exactly what killed the ancient inhabitants of our planet. However, the new computer models show that at that time could be other factors (not just a cloud of dust and volcanic eruptions), who played a key role in the death of most of all life on Earth.
Researchers at the German Potsdam Institute for Climate Change (PIK) believe that the precipitation in the form of sulfuric acid formed in the upper atmosphere when entering it asteroid led to long-term period of global cooling of the planet, who could not stand most of the species existing at the time of the dinosaurs.
"Long-term cooling caused by SCOP in an atmosphere of sulfur particles, had a significant impact on mass extinction process than dust that remains in the atmosphere for a relatively short period of time", - said one of the researchers Julia Brugger.
"It turned out to be even more significant local events, such as extreme temperature at the time of collision, and formed after the fires and tsunamis."
In order to arrive at such conclusions, the scientists used a specific set of computer models, which are called "coupled climate models" and combine climate calculations for both terrestrial and oceanic masses. In fact this is one of the most advanced at the moment climate models.
As in the case of the asteroid hypothesis, widely accepted in the 1980s, as the starting point of a new study, the researchers took the fall of a giant asteroid in the place that is now a Mexican crater Chikshulub. But this time, the researchers decided to look beyond the described increased volcanic activity and short-term dust cloud, surrounding our planet after the attack, and focused on the more dolgoplanovoy term. And it is here "on the scene" went sulfuric acid.
According to the proposed new hypothesis, no dust from the asteroid or volcanic ash, sulfur and those gases formed by the asteroid, has become a key factor in blocking sunlight and general cooling of the climate of the Earth.
The idea of a sulfur-rich rocks around the crater Chikshulub and as a result, occurs in the atmosphere sulfuric acid has already been discussed earlier and has been abandoned, but new computer models give us a better idea of how it could happen. Brugger and her colleagues believe that within 3-16 years after asteroid global temperature could be reduced by 26 degrees celsius becoming below freezing point. Thus on a global temperature recovery could take more than 30 years.
"It was cold. Very, very cold ", - says Brugger.
Temperature changes before and after the asteroid
In addition, the researchers also suspect that the temperature of the ocean surface could also be significantly reduced. This happened due to the lifting of warm water closer to the surface, which could cause massive algae blooms that not only cooled the water which is under them, but also may have been toxic.
According to scientists, nature is still able to teach us important lessons of survival due to sudden climatic changes.
"It is very interesting to explore questions about how the course of evolution has come under the influence of actual ancient cataclysms, such as the fall of the asteroid. Mass extinction has shown how vulnerable is the life on Earth. It is also a perfect illustration of how important is the environment for all forms of life on our planet, "- says George Fyulner, another member of the research discussed today.
"Ironically, today the immediate threat comes not from the natural global cooling, and created by man-made global warming behavior of mankind."