Discuss the multifaceted effects of droughts while emphasizing the distinctions between aridity and drought. (Answer in 150 words)
Model Answer Jet streams are narrow bands of powerful winds located in the upper atmosphere, generally at altitudes of around 30,000 feet (9,100 meters) in the mid to upper troposphere. They form at the boundary where warm and cold air masses meet, creating areas of significant temperature contrast.Read more
Model Answer
Jet streams are narrow bands of powerful winds located in the upper atmosphere, generally at altitudes of around 30,000 feet (9,100 meters) in the mid to upper troposphere. They form at the boundary where warm and cold air masses meet, creating areas of significant temperature contrast.
Types of Jet Streams
- Polar Jet Streams: Found around 50°-60° latitude, typically over the polar regions. These jet streams form above the sub-polar low-pressure belt and have a significant influence on weather systems in mid-latitudes.
- Sub-Tropical Jet Streams: Located around 30° latitude in the subtropical regions, these jet streams are most active during winter and early spring. They can reach speeds of up to 300 knots, and their motion is associated with fair weather conditions.
- Tropical Easterly Jet Streams: These occur near the tropopause over Southeast Asia, India, and Africa during summer. They separate warm and cold air masses and play a role in the region’s monsoonal weather.
Impact of Jet Streams on Weather and Climate
- Weather Patterns: Jet streams mark the boundaries between air masses of differing temperature and humidity. Their interaction can lead to storms, including cyclones, thunderstorms, and rain systems. The meandering of jet streams can also result in prolonged weather events, such as heat waves or cold spells.
- Extreme Weather Events: Disturbances in jet streams contribute to severe weather events. In 2014, jet stream meandering caused intense storms in Europe, leading to record rainfall in England and Wales, and wildfires in Norway due to unusually warm conditions.
- Polar Vortex: A weakened polar jet stream can lead to shifts in the polar vortex, allowing Arctic air to move southward, which can result in colder conditions in mid-latitudes.
- Climate Change: The IPCC reports a poleward shift of jet streams, which could lead to prolonged weather conditions and disrupt local climates. Areas may experience more tropical conditions or intensified dry spells and storms.
Impact on India’s Climate
- Western Disturbance: The upper westerly jet stream during winter brings rainfall to northwestern India, especially regions like Himachal Pradesh and Punjab.
- Monsoon Influence: During summer, the shift of the jet streams influences the Indian monsoon, affecting its timing and strength.
In the context of climate change, understanding the behavior of jet streams is vital to mitigate adverse effects on ecosystems and human populations.
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According to the Aridity Anomaly Outlook Index for July, issued by the India Meteorological Department (IMD) this year, at least 85% of districts faced arid conditions across India. Also, around 21.06 percent of India was facing drought-like conditions, according to the Drought Early Warning System.Read more
According to the Aridity Anomaly Outlook Index for July, issued by the India Meteorological Department (IMD) this year, at least 85% of districts faced arid conditions across India. Also, around 21.06 percent of India was facing drought-like conditions, according to the Drought Early Warning System. Aridity is defined, in meteorology and climatology, as the degree to which a climate lacks effective, life-promoting moisture. Drought is a period of abnormally dry weather sufficiently long enough to cause a serious hydrological imbalance.
The differences between the two include:
Multi-dimensional impacts of droughts are the following:
- Water supply: During droughts, communities may have limited access to water for household use, including drinking, cooking, cleaning, etc. Further, it affects transportation and power generation.
- Agriculture: Droughts affect livestock and crops thereby having a devastating effect on farming and food production, which contributes to food price instability. In countries already facing food insecurity, cost spikes can lead to social unrest, migration, and famine.
- Energy: Droughts can raise concerns about the reliability of electricity production from plants that require cooling water to maintain safe operations. Hydroelectric power may also become unavailable during droughts. Further, when heat waves coincide with droughts, electricity demands can grow, compounding stress on the grid.
- Public health: Reduced flows in rivers and streams due to droughts can lead to a concentration of pollutants, thereby threatening the quality of water used for drinking and recreation. Also, drought-fuelled wildfires can expose nearby communities to smoke and pollutants, which can exacerbate chronic respiratory illnesses.
- Social impacts: Due to frequent droughts, there can be outmigration of the population from drought-affected areas leading to greater indebtedness, alienation from land and livestock assets, malnutrition, starvation, etc. There needs to be regular monitoring of droughts in states by setting up Drought Monitoring Centres (DMCs), which will be staffed by a multi-disciplinary team of meteorologists, hydrologists, and agriculture scientists. Also, state governments and businesses need to identify their vulnerability to droughts and improve resilience by practicing and promoting water conservation and enhancing water efficiency.
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