When the air near the surface becomes extremely warm, absorption of sunlight by atmospheric water vapor heats the air above the surface and forms what's known as an 'inhibition layer,' a barrier that prevents convective clouds from rising into the upper atmosphere and forming rain clouds. In an atmospheric model, Seeley and Wordsworth cranked up Earth's sea surface temperature to a scalding 130 degrees Fahrenheit, either by adding more CO 2 - about 64-times the amount currently in the atmosphere - or by increasing the brightness of the sun by about 10 percent.Īt those temperatures, surprising things start happening in the atmosphere. The research not only sheds light on Earth's distant past and far-flung future but may also help to understand the climates of exoplanets orbiting distant stars.

'This episodic cycle of deluges is a new and completely unexpected atmospheric state' said Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering at SEAS and senior author of the study. Then it would be quiet for a couple of days and repeat.' Then, suddenly, a massive rainstorm would erupt over almost the entire domain, dumping a tremendous amount of rain. 'But we found that in extremely warm climates, there could be multiple days with no rain anywhere over a huge part of the ocean. Paulson School of Engineering and Applied Sciences (SEAS) and the Department of Earth and Planetary Science at Harvard and first author of the paper. 'If you were to look at a large patch of the deep tropics today, it's always raining somewhere,' said Jacob Seeley, a Postdoctoral Fellow in Environmental Science and Engineering at the Harvard John A. In a new study, researchers from Harvard University found that during these epochs of extreme heat, Earth may have experienced cycles of dryness followed by massive rain storms hundreds of miles wide that could dump more than a foot of rain in a matter of hours. Little is known about how the atmosphere and climate behaved during these so-called hothouse periods.

The time it never rained