Iodine accelerates formation of cloud condensation nuclei in the atmosphere
Photochemical reaction chamber. Credit: Hoffmann group

Natural cycles of exchange of substances between the atmosphere and the biosphere are relevant to the Earth's climate. The transfer of carbon between the atmosphere, the land, and the oceans is known as the carbon cycle.

The temperature on our planet's surface is the responsibility of this cycle. Sulfur is an important cycle of elements. The emission of sulfur compounds from marine phytoplankton is assumed to lead to the creation of water vapor-based condensation nuclei in the marine atmosphere.

The stabilization of the Earth's surface temperatures is a result of a natural feedback system. A team of researchers from around the world have identified a new element associated with marine algae. There is a element called IoI. Their work has been published in a journal.

Iodine is part of a group of elements in the water. The levels of iodine are not as high as those of chlorine in the form of sea salt, but it has some strange chemical features.

The process is similar to the sulfur cycle at first. In order to protect their own cell walls, marine phytoplankton convert the iodate in the ocean into iodide.

Iodide at the water surface is released into the air by ozone. A lot of aerosol particles are prone to take the form of iodine oxide, a substance that is very prone to take the form of aerosol particles.

The particles can grow into larger particles that can influence cloud formation. The corresponding process in the case of iodine is not at an end at this point.

Is it possible that new particle formation is caused by the presence of iodine?

The authors of the PNAS article describe how a small amount of the iodine formed in the atmospheric particles is recycled back into the gas phase.

The only element that doesn't leave the atmosphere after being released from the Earth's surface is iodine, which can be returned to the gas phase through redox reactions.

When it comes to cloud formation, it's possible that iodine acts as a catalyst. There are still a number of unanswered questions. It's not clear how much human activity is involved in this process at various points.

More information is available in the Proceedings of the National Academy of Sciences. 10.1073/pnas.

Journal information: Proceedings of the National Academy of Sciences