According to NASA, most global climate models underestimate the amount of rain that will fall in Earth’s tropical regions. This underestimation is clearly attributed to the continues warming of our planet. Also, these models underestimate the decreases in high clouds over the tropics. according to research led by scientist Hui Su of NASA’s Jet Propulsion
Hui Su, lead scientist clarified and answered the question, ‘ How can fewer clouds lead to more rainfall?’. Globally, rainfall isn’t related just to the clouds that are available to make rain. It is also due to Earth’s “energy budget”. “Energy budget”, according to the team, is the incoming energy from the sun compared to outgoing heat energy.
The high-altitude tropical clouds trap this heat in the atmosphere. Fewer the number of clouds, cooler is the atmosphere. Thus, if there are few clouds in the future, the tropical atmosphere will also cool.
Source: NASA
Su and his team used the observations of outgoing thermal radiation from NASA’s spaceborne Clouds and the Earth’s Radiant Energy System (CERES). They also collected data from other satellite instruments, as well as ground-level observations.
After a keen observation on changes in clouds over recent decades, the team, suggests that the atmosphere would create fewer high clouds in response to surface warming. This will also increase tropical rainfall, which would warm the air in order to balance the cooling from the high cloud shrinkage.
Hui Su and his team, patiently explain, how the rainfall warms the air around. While rainfalls are known to create a cool atmosphere on the surface, several miles up in the atmosphere a different process prevails.
When water evaporates into water vapor on Earth’s surface, it rises into the atmosphere. It carries with it the heat energy that made it evaporate. In the cold upper atmosphere, when the water vapor condenses into liquid droplets or ice particles, it releases its heat. This heat, thus warms the atmosphere.
This new study, brings a new insight into the future of the Earth’s climate. This is indeed, one of the most talked-about topic.
