A pity this wasn’t done earlier, before climate alarm took off. But better late than never, if useful results can be obtained. It’s noted that ‘human made particles generally have a cooling effect on the climate.’
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On the rocky slopes high above lush pine forests and mountain lakes, a group of researchers have just finished setting up their gear, says Phys.org.
Even though the weather at sea level is a comfortable 21 degrees, the researchers need their warm clothes. The temperature rarely climbs above 10 degrees at the top this time of the year.
The mountain is Mt. Helmos on the Greek island of Peloponnese. The rocky peak is already home to an observatory, but in the last couple of weeks new scientific equipment has started claiming more and more space up there.
What the researchers hope to do is solve the mystery of cloud formation and changes in cloud properties.
In the quest to better understand how the climate of the Earth works and is shaped by humans, knowing exactly how clouds are formed and respond to human activities are essential.
But to this day, a lot of details about clouds are unknown, explains Ulas Im, senior researcher at the Department of Environmental Science at Aarhus University.
“Understanding cloud formation is essential to make projections like the one thousands of scientists create every five to seven years, when a new IPCC report comes out. Clouds are the biggest uncertainty of the climate projections in these reports. That is why we are trying to better understand them,” he says.
Together with colleagues from all over Europe, Ulas Im is in the center of a giant research project called Clean Cloud. The idea is to learn more on how clouds and particles in the atmosphere interact, using ground-based and satellite observations, laboratory experiments and models.
To do this, large field experiments are planned in the European climate hotspots: The Arctic and the Mediterranean.
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No clouds without particles
The instruments on the mountain top will soon be immersed in clouds. This enables Ulas Im and his colleagues to study how small particles in the air affect cloud formation.
Because, as he explains, particles are the key to understanding clouds. Without particles like dust, pollen, bacteria and exhaust from cars and factories there would be no clouds.
“The basic idea is that you always have water vapor in the atmosphere. Dust or other particles provides a surface for the water vapor to condense on. When the water condenses on these particles they form the cloud droplets,” he says.
But not all particles seed new clouds. Some particles change the characteristics of the clouds instead.
“Clouds have droplets that are liquid or ice. Some clouds are only liquid droplets. A large fraction of clouds are both. Mineral dust or biological particles like pollen are efficient in making ice in the clouds. Without these the temperature required for the droplets to freeze would be much lower.
“With more ice crystals, clouds become transparent to sunlight, which then reach the Earth’s surface. However, with global warming, we move from ice to more liquid clouds. This is important because clouds with more liquid droplets reflect more of the sunlight back into space and this could affect the temperature on Earth.”
Full article here.
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November 4, 2024 at 11:45AM
