The real hues of Red Rain-Kerala, India

This scientific article presents a comprehensive exploration of the intriguing ecological phenomenon known as "red rain", observed in the coastal town located at latitude N 11°.61108 and longitude E 75°.57383 in Kerala, India. The study aims to elucidate the origins, characteristics, and potential environmental implications associated with this phenomenon. Through a meticulous descriptive analysis, incorporating microscopic evaluation, DNA-sequencing, Fourier-transform infrared spectroscopy (FTIR), Gas Chromatography-Mass Spectrometry (GC–MS) analysis, and phylogenetic analysis, we deciphered the underlying factors responsible for the distinct red coloration observed in the rain. Our research findings highlight the presence of specific organic compounds, namely psi-psi Carotene 3,4 didehydro-1,2,7′8'-tetrahydro-1-methoxy-2-oxo and psi-psi and- Carotene 3,3',4,4'-tetradehydro1′2' dihydro 1-hydroxy-1'-methoxy in the algae, Trentepohlia abietina, as the primary contributors to the red color observed in the red rain. The research findings contribute to a deeper understanding of this distinctive occurrence and its implications for the local ecosystem in Kerala.