Pollen: The Surprising Link Behind Cloud Formation and Rainfall


Pollen grains could be the surprising and the previously misunderstood mystery link behind cloud formation, leading to increased rainfall. A recent study published in the journal Geophysical Research Letters, concluded in a laboratory setting, that clouds are formed by six different types of trees and plants. While typically, rain aids flowers in blooming, the new research conducted by atmospheric scientists from Texas A&M and the University of Michigan, suggests that pollen from flowers may help to effectively create clouds and generate rain.

It is common knowledge that clouds are needed for the rainfall. Clouds are created when steam, or gaseous water, decreases into miniature droplets up in the atmosphere. What starts this process are tiny particles recognized as cloud condensation nuclei, which gives water the substance to compress against. However, water does not just grasp onto any particle. It must be the perfect size, which in this case is very small. It must also be the right material, especially something which can absorb moisture.

pollenAllison Steiner, an atmospheric scientist and co-author of the study, has said that scientists used to believe that pollen grains could not function this way due to their large size. Steiner’s work along with others scientists, has now demonstrated how pollen grains break apart when met with moisture, causing fragments that can be thousands of times smaller. These smaller particles are both the suitable size and made up of the proper proteins and hygroscopic carbohydrates to form clouds. Thus, pollen grains could be the surprising and the previously misunderstood mystery link behind cloud formation, which eventually leads to increased rainfall.

As this study was performed in a laboratory, it is still unclear as to what degree pollen influences nature. Steiner is now working to test the distribution and quantity of these particles in the atmosphere. She is eager to measure what effect pollen might have on clouds and climate system. One hypothesis that she finds specifically compelling, is the idea that trees might be affecting the amount of rain they themselves get. This might give a whole new understanding of the age-old belief and the established scientific fact that an area with more trees gets more rainfall and vice versa. When clouds become thicker, they eventually produce more rain. However, pollen could actually delay the extent at which the rain falls by enabling cloud formation.

Normally, clouds do not precipitate as long as they are still growing and becoming thicker. However, thicker clouds deliver more rain along with intense downpours compared to thinner clouds. Due to pollen, clouds could reflect more sunlight which could lead to local cooling, if it can help build whiter and thicker clouds. Factoring in climate models which could help in improving these effects, it will be interesting to see how significant it is in the real world.

Pollen grains could be the surprising and the previously misunderstood mystery link behind understanding cloud formation, which eventually leads to increased rainfall. The fact is, massive deforestation around the world for use of land as industrial and residential zones, and wood for numerous reasons, is one of the main reasons for climate change. Places like California have been reeling with drought and minimal rainfall for years now. The situation is only bound to get worse if this trend continues.

By Ankur Sinha


Photos by:
Markos Loizou-Creativecommons Flickr License
Ian-Creativecommons Flickr License

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