These showers brought not the rainbow, but yellow-coloured raindrops
When the raindrops dried off, white school uniforms had yellow spots
The rain was invisibly yellow in Wayanad, Kerala, on Friday morning
Rainfall in November is not something people in Kerala would worry about. Except that when the raindrops dried off the uniforms of schoolchildren in parts of Wayanad district on Friday, villagers were both intrigued and frightened as they left behind yellow spots.
The Meppady region of Wayanad district received yellow-coloured rain on Friday. Although not visible to the eye while it was raining, the yellow colour was distinguishable when the raindrops fell on solid surfaces.
“Early in the morning we saw some yellow-coloured water drops on the plants which we neglected. But later around 9 am once more yellow rain was spotted,” says K Rajan a shopkeeper in Meppady.
The colour was most clearly visible in schools, where children were wearing white.
“It started raining in the morning when it was time for children to come to school. It wasn’t raining very heavily, and the colour was not visible. But there were yellow spots on white surfaces,” Principal of St Joseph Higher Secondary School, Meppady V Sasikumar said.
Scientists are only slightly less puzzled than others about why the rain has occurred.
“We don’t know the reason yet, we are yet to examine the samples. Sometimes minor sky cyclones can be the cause, but we cannot be sure,” said an officer at Thiruvananthapuram meteorological department on condition of anonymity.
A scientist at the National Centre for Earth Science Studies in Thiruvananthapuram who requested anonymity said, “The mystery of red rain phenomena is still not resolved, studies are going on. This yellow rain can also be caused by certain chemical changes. An in-depth study will have to be made to describe the exact reason.”
In 2013, yellow rain was reported from Cherthala in Alappuzha district but the matter was dropped, as the intensity of the rainfall was low.
Even before the Kerala region received yellow rainfall, red-coloured rain was reported from some parts as early as 1896, according to The Hindu. The last time this phenomenon occurred, was in 2013, in Idukki district.
In 2006, the Guardian reported that according to a study, alien bacteria could cause the rain to appear red.
The Hindu reported that according to a study published in the Phylogenetics and Evolutionary Biology journal, red colour in rain was caused by the presence of spores of Trentepohlia annulata, a species of green microalgae, which was reported previously only from Austria.
While the presence of the spores was confirmed, how they came to be over Kerala when they had not been seen there ever in the past, is something that researchers are still unable to explain.