Discovery of atmospheric ‘memory’ could ımprove climate forecasting
Baku, June 10, AZERTAC
Israeli scientists have found that atmospheric particles known as aerosols can briefly warm the planet before ultimately contributing to cooling, a finding that could improve climate forecasting, according to TPS-IL.
Aerosols are tiny particles in the air produced by sources such as pollution, wildfires, dust storms, sea spray and industrial activity. Scientists have long known that they influence clouds and temperature, but the new research shows that the timing of those effects is just as important as their size or concentration. Because their effects can shift over time, current climate models may miss important short-term warming and longer-term cooling responses, making it harder to predict future temperature changes accurately.
Using computer simulations, a team of scientists led by Guy Dagan of the Hebrew University of Jerusalem’s Fredy and Nadine Herrmann Institute of Earth Sciences examined what happens after a sudden increase in aerosol levels. They found that during the first couple of days, the atmosphere can actually warm. This happens because changes in cloud behavior lead to the formation of more high-altitude clouds, which trap heat that would otherwise escape into space.
However, they also found that this early warming does not last. The simulations showed that this atmospheric “memory” becomes apparent as cloud systems continue to evolve after the initial aerosol increase.
“Much of what we know about aerosol-cloud interactions comes from observing the atmosphere at a single moment in time,” said Guy Dagan. “Our results show that the atmosphere has a memory. The climatic impact of aerosols depends not only on how many particles are present, but also on how rapidly conditions are changing and how much time the atmosphere has had to respond.”
As the atmosphere adjusts, conditions in the upper layers begin to shift. Cloud systems evolve, and over time they allow more heat to escape into space. At that point, the overall effect flips, and aerosols begin to produce a cooling influence.
In simple terms, the same particles can warm the planet in the short term and cool it later, depending on how long the atmosphere has had to respond.
The study also introduces the concept of “atmospheric memory,” meaning the climate impact of aerosols depends not only on how many particles are present at a given moment, but also on whether their levels have recently been rising or falling.
This means that two identical pollution levels could still produce different climate outcomes depending on recent changes in atmospheric conditions.
Researchers say the findings point to a potential upgrade in climate modeling, shifting from static “snapshot” assumptions toward systems that track how aerosol levels and cloud responses evolve over time. That change could improve both short-term forecasts of climate fluctuations and long-term projections of global warming.
The researchers said the findings could help policymakers better understand the near-term climate effects of changes in emissions regulations, particularly in heavily polluted regions.
The findings were published in the peer-reviewed Nature Communications.
Other news in this section
