Why this?
Cyclone Asna was a rare August storm in the Arabian Sea, but just blaming climate change and discussing it is oversimplifying the topic. This article kicks off by analyzing past trends and what caused them, before diving into the rising frequency of cyclones in the Arabian Sea, especially post-monsoon. Our take offers a fresh perspective, connecting the dots between climate change and extreme weather events, making sure you’re fully prepped with the insights you need.
GS Paper 1: Geography and Indian Society: Salient Features of World’s Physical Geography
Note4Students: Understand the relationship between cyclones, sea surface temperatures, and climate change, and their effects on global weather patterns.
Microtheme: Climatology
GS Paper 2: Governance, Constitution, Polity, Social Justice, and International Relations: Government Policies and Interventions for Development in Various Sectors
Note4Students: Learn about the necessity of climate resilience policies, especially in coastal regions vulnerable to increasing cyclone frequency.
Microtheme: Miscellaneous
GS Paper 3: Environment, Disaster Management, and Science & Technology: Disaster Management
Note4Students: Explore strategies for cyclone preparedness and the role of early warning systems in minimizing damage from natural disasters.
Microtheme: Climate change impact
GS Paper 4: Ethics, Integrity, and Aptitude: Ethics in Climate Change and Environmental Conservation
Note4Students: Analyze the ethical responsibilities of nations and individuals in addressing climate change and protecting the environment for future generations.
Microtheme: Ethical Issues in International Relations and funding
How is ‘Asna’ different ?
“Asna” is notable because it’s the first cyclone in August in the North Indian Ocean since 1981. August is typically not part of the cyclone season in this region. The cyclone began as a land-born depression that intensified as it moved over the warm waters of the Arabian Sea. It formed from a rare strong low-pressure system that grew unusually powerful over land. Asna’s formation is linked to the broader context of rapid warming over the Arabian Sea, influenced by climate change. The northward shift of the low-level jet stream due to warming over West Asia contributed to its development
Trends of Cyclones in Arabian Sea
Historical Trends: The Arabian Sea historically experienced 2-3 cyclones per year, mostly weak, with a 1:4 ratio compared to the Bay of Bengal. From 1891 to 2000, 48 tropical cyclones impacted India’s west coast, 24 of which were severe, while the east coast experienced 308 cyclones, including 103 severe storms. Cyclones typically occur in May-June (pre-monsoon) and October-November (post-monsoon). Cyclone formation in the Arabian Sea is common pre-monsoon but rare in post-monsoon, when the Bay of Bengal usually sees cyclonic activity.
Current Trends: Recent trends show increasing frequency and timing shifts in cyclones over the Arabian Sea. Sea surface temperatures (SST) remain abnormally high, at around 30°C, fueling cyclone formation. Since 1980, 2021 marked the first time pre-monsoon cyclones occurred four years in a row. Cyclones are also moving closer to India’s west coast, with 2018 seeing three cyclones in the Arabian Sea and 2019 witnessing five, compared to the usual one. Between 2014-2019, there was a 32% rise in cyclones. The intensity of cyclones has also increased, with Tauktae being the fifth-strongest storm in the Arabian Sea since 1998 and the strongest pre-monsoon cyclone since 2010. Severe post-monsoon cyclones, such as Nilofar (2014), Chapal, and Megh (2015), occurred unusually during October and November.
Reasons for Increasing Frequency of Cyclones in the Arabian Sea
| Reason | Explanation | Substantiation |
| Climate Change and Global Warming | Rising ocean temperatures increase cyclone formation as cyclones draw energy from ocean heat. | Climate scientist Hiroyuki Murakami’s study showed 64% of recent cyclones in the Arabian Sea were caused by climate change. |
| Temperature Rise in Indian Ocean | Over the last 4 decades, the Indian Ocean’s temperature rose by 0.7°C; the western Indian Ocean unexpectedly warmed by 1.2°C in summer. | The IMD noted the Arabian Sea’s surface temperature is 30-31°C, especially around Goa-Lakshadweep, where Cyclone Tauktae originated. |
| Indian Ocean Dipole (IOD) | A positive IOD warms the western Indian Ocean and Arabian Sea, creating low-pressure areas conducive to cyclone formation. | In 2019, 5 cyclones formed in the Arabian Sea, coinciding with the strongest positive IOD recorded. |
| Teleconnections | Distant climate phenomena, such as atmospheric or oceanic changes, can impact cyclone patterns in the Arabian Sea. | A study by the National Institute of Oceanography, Goa, suggested teleconnections influence cyclone activity. |
Reasons for Increased Frequency of Severe Cyclonic Storms in the Post-Monsoon Period
| Reason | Explanation | Substantiation |
| Shift in Cyclone Occurrence | Severe cyclones, which typically occur in spring, are now occurring in the post-monsoon period (October-November). | Severe cyclones Nilofar, Chapal, and Megh occurred in October-November. In 2019, Kyarr, Maha, and Pawan formed post-monsoon. |
| Rising Sea Surface Temperature (SST) | Increased SST, linked to human activity and natural variability, is intensifying cyclones, making them more severe. | SST rise in the Arabian Sea leads to more intense storms, especially during the post-monsoon period. |
| Delayed Winter Monsoon | The delay in the onset of the winter monsoon extends the storm season, leading to an increase in severe cyclones. | Delayed monsoons contribute to longer cyclone seasons and more severe storms in the Arabian Sea. |
| Anthropogenic Aerosols | Aerosols from post-harvest activities change SST distribution, leading to more active cyclonic storms during the post-monsoon season. | After the kharif harvest, increased aerosol emissions influence SST and cyclonic storm activity in the Arabian Sea. |
#CLIMATE EXTREMES & CLIMATE CHANGE
According to IPCC -AR6, changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of weather and climate extremes. • While many weather and climate extremes are the result of natural climate variability (including phenomena such as El Niño), and natural decadal or multi-decadal variabilities, it is the anthropogenic activities which are the driving force in climate change.
As a consequence, average temperatures have risen by 1.2 C compared to pre industrial era. This additional energy is unevenly distributed and bursts out in extremes events disasters like hurricanes, heat-waves, cloud bursts, droughts etc.
For example: Some of the extreme events that have been experienced around the world are:
- A heat wave in Canada and adjacent parts of the USA pushed temperatures to nearly 50C in a village in British Columbia.
- Death Valley, California reached 54.4C during one of multiple heat waves in the south-western USA.
- A second successive year of drought in sub-tropical South America reduced the flow of river basins and hit agriculture, transport and energy production
| Extreme Event | Impact | Example |
| Drought | Climate change is shifting the equilibrium of the water cycle, making large regions more drought-prone by 2100. | The Standardized Precipitation-Evapotranspiration Index indicates more drought-prone conditions, particularly in mid-latitude regions. |
| Extreme Precipitation | Warmer air holds more water vapor (7% more per degree of warming), leading to more intense and variable precipitation events, increasing both floods and droughts. | Increased risk of flooding and dam failure during heavy rains, while water storage becomes critical during droughts. |
| Tropical Storms | Tropical storms and hurricanes are shifting towards the poles due to expanding tropics caused by higher global temperatures. | Warmer sea temperatures could intensify hurricane wind speeds by up to 10%. Hurricanes Florence (2018) and Imelda (2019) caused devastating floods due to this shift. |
| Coastal Storms and Storm Surges | Rising sea levels (by 1-4 feet globally) in low to moderate emissions scenarios will amplify the impact of coastal storms and storm surges. | Hurricane Ida in 2021 hit Louisiana, US, as an extremely dangerous Category 4 storm, with increased damage due to rising sea levels and coastal storm surges. |
| Warmer Sea Surface Temperatures | Higher sea surface temperatures lead to more low-pressure systems, increasing the likelihood of stronger and more frequent tropical storms. | NOAA has predicted an increase in Category 4 and 5 hurricanes, with wind speeds rising by up to 10%, intensifying storms like Hurricane Florence and Hurricane Imelda. |
| Wildfires | Warmer, drier conditions caused by climate change increase wildfire risk by affecting temperature, soil moisture, and fuel availability (trees, shrubs). | In the U.S. West, a 1°C rise could increase the median burned area by up to 600% in some forests. |
Hello,
We have a confession: we’re here to compete with your notes! Burning Issues magazine is your go-to resource as your exam approaches, designed to help you through the anxiety and overwhelm of preparing for the Civil Services Examination.
Many aspirants struggle despite reading current affairs for a year. This often happens because they interpret current affairs as merely news. As a UPSC aspirant, it’s essential to analyze these topics from the perspectives of General Studies 1, 2, 3, and 4, and that’s exactly what Elevate does.
This magazine features two sections: Burning Issues and Prelims Tidbits. Burning Issues covers current affairs that may appear in your Mains papers and teaches you how to think about these topics from different GS perspectives in just two pages.
Prelims Tidbits simplifies your Prelims preparation by distilling key facts, data, and concepts into easy-to-recall points framed around basic questions: What? Who? How? When?
So, dive in! Every page is crafted to enhance your UPSC prep. With consistency and this magazine, you’re not just preparing; you’re mastering the exam. The journey is about understanding and applying your knowledge effectively.
