It expects candidates to write in detail the effect of change in pattern of the Asian monsoon on various parts of the world with relevant recent examples.
Introduction:
The Asian monsoon is one of the most vigorous climatic phenomena on Earth and also one of the most societal important. The monsoon drives vital seasonal rainstorms that water crops and forests as well as damaging typhoons and floods
Body:
In a typical year, 80%–85% of the rain in the affected regions, often totalling 1.5–2.5 meters, falls during the summer monsoon season. On longer timescales, scientists have often cited the evolution of this seasonal wind flow over millions of years as one major cause of past changes in the environments, biosphere, and oceanography of this region, which includes the Indian subcontinent, Southeast Asia, China, Korea, and Japan. Following changes are observed in the pattern of the Asian Monsoon:
The onset of the monsoon has been delayed almost every year since 1976, when there was a regime shift in climate around the world – from a weak to a strong El Niño period.
Monsoons have also been ending sooner – almost a week from the end of September – so the length of the rainy season has been compressed.
During the monsoon season, there are usually random “break periods” when there is hardly any rainfall. These periods are associated with systems moving northwards from the equatorial region. All available data and models-blended-with-data (known as reanalysis) indicate that global warming is shortening the length of the “active periods” when it does rain, while lengthening the break periods.
Effect of change in pattern of the Asian monsoon on various parts of the world:
Indian monsoon is considered a ‘textbook phenomenon’ clearly defined which has not changed much in the preceding century.
However this process has hit an erratic front, with floods in the northwest and the northeast and rainfall deficit in southern part of the nation.
Rainfall extremes have increased threefold over the last few years and now extend over all of central India – from Gujarat to Odisha.
Onset of monsoon has delayed every year since 2002 and it also lasts for shorter duration, compressing the Indian monsoon.
The interspersed breaks in the monsoon have increased resulting in larger drier periods in the monsoon itself.
Rainfall intensity, duration, frequency and spatial distribution have significantly undergone change in the past decade or two.
Cycles of droughts and floods have become more common in many parts of India and their intensity has changed over the time. e.g. Cyclone Amphan.
Also now cyclones are also started to occur on the western coast of the countries. e.g. Cyclone Vayu.
Areas that have traditionally received plenty of rainfall are often remaining dry, while places that are not expected to get a lot of monsoon rain have sometimes been getting flooded.
The intensity and amount of rainfall over the region has increased drastically. For instance, Typhoon Kammuri in Phillipines and Flooding in parts of China.
The agricultural cycle of sowing to harvesting is facing tremendous challenge as unprecedented breaks and excess rainfall in short period of time making difficulty to set sowing pattern.
Many of the metro cities are receiving excessive rainfall as compared to their average normal. e.g. Recent flooding in Mumbai.
Also some experts opined that Australian bushfires partly due to late monsoon ending in India.
The lack of water in other areas has hit water table levels. By 2030, India is expected to require almost 1.5 trillion m3 of ground water, where the current supply is only 740 billion m3, putting a huge pressure on the river basins, which are facing challenges of their own due to fast-disappearing glaciers and reduced rainfall.
In recent times it is proved that monsoons are (nearly) unpredictable natural disasters. Hence, following steps are needed to tackle this crisis:
Need to change crop cycles, credit cycles, create storage infrastructure to deal with flooding.
We need to invest in developing the state of the art technology to predict the accurate data regarding the monsoon cycle.
Also, we need modification in the approach of handling of disasters by NDRF and SDRF as the intensity of the rainfall is extreme in some cases.
Change in the type and variety of crops and change in the kind of inputs used by farmers to deal with the altered reality is needed of the hour.
Conclusion:
The effect of change of monsoon cycle over different parts of the world is wide scale. However, adoption of state of the art technology and investing more in research to know how the change in Asian monsoon will surely help to tackle this challenge successfully and avoid any loss in future.
