From UPSC perspective, the following things are important :
Prelims level: Anticyclone and El Nina
Mains level: Link between anticyclone and heat
Why in the news?
The record warming of 2023 has so far not been fully explained since it was much warmer than expected just from the superposition of El Nino on global warming.
About Anticyclone:
- An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
The link between ElNino and Anticyclone:
- El Nino events can lead to the formation of anticyclone events. During El Niño, the weakening or reversal of the Walker circulation and strengthening of the Hadley circulation caused warm ocean water to develop in the central and east-central equatorial Pacific.
The link between anticyclone and heat
- Stability and Weather Patterns: Anticyclones are areas of high pressure in the atmosphere characterized by descending air, which stop the cloud formation and precipitation. This stable air mass tends to promote clear skies and can lead to prolonged periods of hot and dry weather.
- Amplification by Global Warming: Studies suggest that global warming can intensify anticyclones, making them stronger and more persistent. Warmer temperatures due to climate change can enhance the evaporation of moisture from land and water surfaces, further reinforcing the stability of anticyclonic conditions.
- Feedback Loop: Anticyclones can create a feedback loop with global warming. As anticyclones persist, they can exacerbate heatwaves by trapping heat near the surface, preventing it from escaping into the upper atmosphere. This trapped heat can then further strengthen the anticyclone, leading to a self-reinforcing cycle of heat and stability.
What are the stages of early warnings?
The stages of early warnings on the ‘ready-set-go’ system for disaster management
- Ready: This stage involves providing a seasonal outlook based on background states and external factors like global warming and El Niño. The aim is to maximize the accuracy of longer-lead forecasts, enabling organizations like the National Disaster Management Agency (NDMA) and local governments to prepare their disaster response systems accordingly.
- Set: In this stage, subseasonal predictions for weeks two to four are utilized. Resource allocations are made, and potential hotspots are identified to ensure that disaster preparedness is in place. This step involves moving resources, including personnel, to areas that are identified as at risk based on the extended range forecasts.
- Go: The final stage, based on short- and medium-range forecasts (days 1-10), involves the activation of disaster response efforts. This includes implementing rescue operations, setting up hydration centers, heat shelters, and other necessary measures to manage the disaster effectively.
Conclusion: All evidence suggests India’s prediction system and early warning systems continue to improve and the NDMA has worked these details well into its ‘ready-set-go’ system.The remaining challenges are to build resilience for the future by better predicting the trajectory of the weather at every location over India.
Mains PYQ
Q Drought has been recognized as a disaster in view of its spatial expanse, temporal duration, slow onset and lasting effects on vulnerable sections. With a focus on the September 2010 guidelines from the National Disaster Management Authority (NDMA), discuss the mechanisms for preparedness to deal with likely El Nino and La Nina fallouts in India.
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