COPENHAGEN, Denmark, Aug. 29 (UPI) -- For the first time, climate models are allowing scientists to understand how complex cloud systems form and generate severe storms.
A team of researchers in Europe were able to analyze the formation of heavy rain and severe thunderstorms by focusing on a small component of a broader climate model. The high-resolution cloud model works by zooming in on just the portion of the geographical area modeled in a larger climate simulation -- an area of 200 meters by 200 meters as opposed to 200 kilometers by 200 kilometers.
The increased resolution offered researchers insights into rainstorm formation processes taking place in the atmosphere.
"To detect the physical process that form, for example, storm clouds, we use simulations that are capable of revealing local thermal and moisture variations, which give rise to so-called 'convective' clouds," Jan O. Haerter, a researcher with the Niels Bohr Institute at the University of Copenhagen, explained in a news release. "Convection is the process that forms, for example, thunderstorm clouds."
The new model focused on the effects of temperature on convection, a process given relatively less attention by larger climate models. The new simulations showed that as the Earth's surface warms, an updraft of warm air is released, encouraging cloud formations to coalesce into larger, more complex systems.
"Where two clouds collide, new and stronger clouds often appear," Haerter said.
The model revealed patterns within these formation systems, or what scientists call "memory."
"What we see here is a so-called complex system," Haerter said. "The way the atmosphere behaves is not only influenced by large scales, but is also due to what we call self-organisation. Convective clouds come and go within a certain period. Over the course of the day, these periods increase and so does the intensity of rain."
The combination of larger and larger clouds yields heavier rainstorms.
Global climate models have incorrectly treated convective clouds as independent systems.
The research, detailed in the journal Nature Geoscience, could improve global climate models as well as severe weather predictions.
"With the new model calculations, we are getting a better understanding of the intense thunderstorms that can lead to the severe flooding that often occurs in temperate latitudes," Haerter said.