A Distant Pacific Pattern May Be Drying North India: Study, Pg12

Key Highlights:

• A recent study by the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM) links climatic shifts in India to a Pacific Ocean phenomenon.
• The study identifies the Victoria Mode (VM), a recurring pattern of warm and cool surface water in the North Pacific, as a key driver.
• Northwest India has seen its hot, semi-arid steppe zone expand from 25.7% to 33.1% between 1951-80 and 1991-2020.
• Drying in northern India, including parts of Uttar Pradesh, Bihar, and Gangetic West Bengal, is attributed to the negative phase of the Victoria Mode.
• The research, published in MAUSAM, highlights concerns about food security and population displacement due to these climatic changes.

Victoria Mode.jpg

Detailed Insights:

• The Victoria Mode is distinct from the more commonly known Pacific Decadal Oscillation (PDO), though both are Pacific patterns.
• In the northeast, the tropical savannah zone decreased, while the temperate zone expanded, indicating a shift towards milder conditions.
• Peninsular India experienced a decrease in the hot semi-arid steppe zone and an increase in the tropical savannah zone.
• Coastal regions like Konkan, Goa, coastal Karnataka, and Kerala observed an expansion of their tropical monsoon zones.
• The study notes that previous research has often linked Victoria Mode events to subsequent El Niño events.
• The current global El Niño is one of the strongest recorded, contributing to a 12% reduction in India's monsoon rainfall this year.
• The Pacific Decadal Oscillation also correlates negatively with Indian monsoon rainfall, similar to the El Niño-La Niña cycle.

Scientific/Technical Concepts Involved:

• Victoria Mode (VM): A recurring pattern of warm and cool sea surface temperatures in the North Pacific Ocean.
• Pacific Decadal Oscillation (PDO): A long-term ocean fluctuation of the Pacific Ocean, characterized by warm or cool phases in the North Pacific.
• El Niño: A climate pattern describing the unusual warming of surface waters in the eastern tropical Pacific Ocean.