With rain, dead lands are brought back to life to sprout flowers of all kinds, and it seems that the latter return the favour: a new research has shown that pollen from flowers might be aiding in the process of cloud formation that is ultimately responsible for rainfall. The findings were published in the journal Geophysical Research Letters.
A team of atmospheric scientists from the University of Michigan and Texas A&M have observed how pollen from 6 plants formed clouds in laboratory. Otherwise, it is known that clouds are made from water in the gaseous state (or, steam) which then condenses into droplets. This process starts off with small particles called cloud condensation nuclei that provide a ‘surface’ for the water to condense on. The particles need to be of the right size and right material (hygroscopic carbohydrates and proteins) so that the moisture can be absorbed. It seems that that is where pollen helps.
While it was previously thought that pollens are too big to function like that, the scientists of the study found that pollen grains divide in such a way that when they come into contact with moisture, particles that can be thousands of times smaller are produced – these particles happen to be of the right size and material to form clouds.
An atmospheric chemist and climate scientist, Athanasios Nenes, who was not involved in the study said in a statement that “pollen can help clouds form, and you might affect the cloud properties enough that you could change the rain”.
The study was done in laboratory. Whether the same happens in the real environment is thus not clear. As a matter of fact, more research is needed to identify the role of pollen in cloud formation, if any. Allison Steiner, co-author of the paper, states that she is already focusing on the next step that entails testing the quantity and distribution of the particles in the atmosphere to gauge the effect pollen might be having on clouds, and hence on weather patterns. Steiner is of the opinion that “the results translate to the real world. Certainly [pollen] is involved in cloud formation in specific areas at specific times of the year…but how much of the time, that’s something we’re still trying to understand.”
One of the speculations she finds intriguing is that “trees themselves could be influencing the amount of rain they get.” For instance, if pollen can influence the thickness or whiteness of clouds by helping in cloud formation, it might be putting off the time when rain falls.