A distant Pacific phenomenon may be drying India’s north, says study

A recent study by scientists from the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM) suggests that a lesser-known Pacific phenomenon may be contributing to drought conditions in northern India. The study, published in the journal MAUSAM, reveals that the north-western region of the country, which includes states like Uttar Pradesh and Bihar, has seen a significant shift in its climate zones over the past few decades.

According to the researchers, the once-tropical savannah and temperate zones have been shrinking, while the hot, semi-arid steppe zone has been expanding. In the 1951-80 period, the steppe zone covered 25.7% of the region, but by 1991-2020, it had grown to 33.1%. Meanwhile, the temperate zone, which used to cover 25.8% of the area, shrank to 18.7%. This change has been attributed to the "Victoria Mode" (VM), a Pacific Ocean phenomenon characterized by warm and cool surface water patterns.

The authors of the study warn that this drying trend in northern India could have serious implications for food security and local population displacement. They attribute the changes to the negative phase of the VM, which they claim has reduced the moisture flow in the region. The continuing shrinkage of tropical savannah and temperate zones could lead to numerous problems related to food safety and population displacement.

The study also highlights the expansion of tropical savannah zones in peninsular India, particularly in regions like Konkan, Goa, coastal Karnataka, Kerala, and Mahe. On the other hand, areas like Western Saurashtra and Kutch have moved from arid to semi-arid conditions. The researchers note that the current El Niño event, which has led to a 12% reduction in India's monsoon rainfall, may be unprecedented in strength, further exacerbating the water scarcity in the region.