The Southwest Monsoon, also known as the summer monsoon, is a seasonal wind system that brings heavy rainfall to the Indian subcontinent and Southeast Asia. While the monsoon is a natural and complex phenomenon, there are several factors that can contribute to its failure or weaker performance in a given year. Here are some possible reasons behind the failure of the Southwest Monsoon
El Niño: El Niño is a climate pattern characterized by warmer-than-average sea surface temperatures in the eastern Pacific Ocean. During El Niño years, the formation and intensity of the monsoon can be disrupted, leading to reduced rainfall over the affected regions. El Niño events can weaken or delay the onset of the monsoon, resulting in below-normal rainfall.
La Niña: La Niña is the opposite of El Niño, characterized by cooler-than-average sea surface temperatures in the eastern Pacific Ocean. La Niña events can also impact the monsoon, but in a different way. They can enhance the monsoon rainfall in some regions, while causing deficits in others. The exact impact of La Niña on the Southwest Monsoon depends on its strength and other atmospheric conditions.
Indian Ocean Dipole (IOD): The IOD is another climate pattern that affects the monsoon. It refers to the difference in sea surface temperatures between the western and eastern parts of the Indian Ocean. A positive IOD, characterized by cooler waters in the east and warmer waters in the west, can enhance the monsoon, while a negative IOD can have the opposite effect. The state of the IOD can influence the strength and distribution of rainfall during the monsoon season.
Madden-Julian Oscillation (MJO): The MJO is a tropical atmospheric disturbance that travels eastward around the globe. It can affect the monsoon by modulating the strength and timing of rainfall. The MJO's position and intensity can impact the monsoon's performance, causing fluctuations in rainfall patterns.
Changes in sea surface temperatures: Variations in sea surface temperatures in different parts of the oceans, such as the Indian Ocean, the Arabian Sea, and the Bay of Bengal, can influence the monsoon. Unusual temperature patterns, such as warm or cold anomalies, can disrupt the monsoon circulation and rainfall patterns.
Atmospheric conditions and local factors: Other atmospheric conditions, such as wind patterns, moisture content, and atmospheric pressure systems, can also impact the monsoon. Local factors such as land use changes, deforestation, and urbanization can modify the microclimate and affect the monsoon rainfall in specific areas.
It's important to note that the failure or weak performance of the Southwest Monsoon in a given year can be influenced by a combination of these factors, and their interactions are complex and not yet fully understood. Climate scientists continue to study and monitor these patterns to improve monsoon predictions and understand the underlying mechanisms.
