Climate change may cause more rainfall in tropical areas: NASA
The amount of rainfall in tropical regions of the Earth increases significantly as the planet continues to heat up, new NASA study warns.
Most of the global climate models underestimate diminishes high clouds in the tropics seen in recent NASA observations, according to research conducted by the Hui Su Scientific Propulsion Laboratory at NASA’s manometer (JPL) in the United States.
Globally, precipitation is not only tied to the cloud at the disposal of the rain, but also the “energy balance” of the Earth – the energy coming from the Sun in relation to the outgoing thermal energy.
At high altitude tropical clouds trap heat in the atmosphere. If there are fewer of these clouds in the future, the tropical atmosphere will cool.
Judging from changes in clouds over the past few decades, it appears that the atmosphere would create fewer high clouds in response to surface warming.
This would also increase tropical rainfall, which will heat the air to balance the cooling of the large cloud retreat. The warmer air also seems contradictory rainfall – people are accustomed to rain cooling the air around them, do not let it get hot.
Several miles into the atmosphere, however, a different process prevails.
When water evaporates in vapor here on the surface of the Earth and rises in the atmosphere, it causes the thermal energy to evaporate.
In the cold high atmosphere, when water vapor condenses into liquid droplets or ice particles, it releases its heat and heats the atmosphere.
The reduction of high cloud cover is brought into context as a result of a global change in the large-scale airflow that occurs when the temperature of the Earth’s surface is warming.
These currents are called large-scale atmospheric general circulation, and they include a large zone of air centered upwards on the equator.
Observations over the past 30 to 40 years have shown that this area is gradually shrinking as the weather warms up, resulting in fewer high clouds. JPL researchers and four universities compared climate data from past decades with 23 simulations of climate models from the same era.
Climate modelers use backward simulations like this to see how their numerical models are able to reproduce observations.
For the data, the team used the thermal radiation coming out of the clouds NASA’s spatial comments and the Earth’s radiant energy system (CERES) and other satellite instruments and observations in the ground.
They found that most climate models underestimated increased rainfall in the rate for each degree of surface warming that has occurred in recent decades.