The future will bring us fewer clouds but it will be Rainier.
As our planet continues to warm, NASA suggests that the future in Earth’s tropical regions will be Rainier.
In the future, there will be fewer clouds. But how could clouds lead to more rainfall? NASA says that rainfall isn’t related just to the clouds that are available to make rain. It’s also related to Earth’s incoming energy from the sun compared to outgoing heat energy.
High-altitude tropical clouds trap heat in the atmosphere. That means if there are fewer of these clouds in the future, the tropical atmosphere will cool.
The journal Nature Communications published the new study. It puts the decrease in high tropical cloud cover in context as one result of a planet-wide shift in large-scale air flows that are occurring as Earth’s surface temperature warms. Astronomers are calling these large-scale flows, the atmospheric general circulation. They include a wide zone of rising air centered on the equator.
Observations from the past suggest that the atmosphere would create fewer high clouds in response to surface warming. That would increase tropical rainfall, which would warm the air to balance the cooling from the high cloud shrinkage, according to the research led by Hui Su of US space agency NASA’s Jet Propulsion Laboratory in Pasadena, California.
“This study provides a pathway for improving predictions of future precipitation change,” Su said in a statement.
Su and colleagues at JPL and four universities compared climate data from the past few decades with 23 climate model simulations of the same period. Climate modelers use retrospective simulations like these to check how well their numerical models are able to reproduce observations.
Observing this data.
For this data, the team used observations of outgoing thermal radiation from NASA’s space-borne Clouds and the Earth’s Radiant Energy System (CERES) and other satellite instruments, as well as ground-level observations.
Su also mentioned that by tracing the underestimation problem back to the models’ deficiencies in representing tropical high clouds and the atmospheric general circulation, “This study provides a pathway for improving predictions of future precipitation change.”