Extreme Weather Conditions in Bangladesh
Bangladesh is highly susceptible to various extreme weather events due to its unique geographic location and climatic conditions. The country's vulnerability is largely influenced by the state of two major climate phenomena: the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). Here's an overview of the expected extreme weather conditions in Bangladesh under different ENSO and IOD scenarios:
(a) ENSO and IOD Positive
Extreme Weather Conditions:
• Heatwaves: Prolonged and severe heatwaves are likely, with temperatures exceeding 40°C (104°F) for extended periods.
• Heavy Rainfall: Increased chances of heavy rainfall and flooding, particularly during the monsoon season.
• Cyclones: Higher frequency and intensity of tropical cyclones making landfall in Bangladesh.
Justification:
• During a positive ENSO (El Niño) phase, the eastern Pacific Ocean experiences warmer than average sea surface temperatures (SSTs), which can lead to enhanced convection and moisture transport towards South Asia.
• A positive IOD phase is characterized by warmer than average SSTs in the western Indian Ocean and cooler than average SSTs in the eastern Indian Ocean. This can amplify the effects of El Niño, leading to more extreme weather patterns in the region.
• The combination of a positive ENSO and a positive IOD typically results in drier and hotter conditions in Bangladesh, increasing the risk of heatwaves and droughts. At the same time, the enhanced moisture transport can contribute to heavier rainfall events and more frequent and intense cyclones.
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(b) ENSO and IOD Negative
Extreme Weather Conditions:
• Heatwaves: Reduced risk of severe heatwaves compared to the positive ENSO and IOD scenario.
• Heavy Rainfall: Decreased chances of heavy rainfall and flooding, especially during the monsoon season.
• Cyclones: Fewer tropical cyclones making landfall in Bangladesh.
Justification:
• During a negative ENSO (La Niña) phase, the eastern Pacific Ocean experiences cooler than average SSTs, which can lead to a weakening of the monsoon system and reduced moisture transport towards South Asia.
• A negative IOD phase is characterized by cooler than average SSTs in the western Indian Ocean and warmer than average SSTs in the eastern Indian Ocean. This can partially offset the effects of La Niña, resulting in a more moderate impact on extreme weather patterns in Bangladesh.
• The combination of a negative ENSO and a negative IOD typically results in relatively cooler and drier conditions in Bangladesh, lowering the risk of heatwaves and droughts. The reduced moisture transport can also lead to a decrease in heavy rainfall events and tropical cyclone activity.
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(c) ENSO Positive, IOD Negative
Extreme Weather Conditions:
• Heatwaves: Increased risk of heatwaves, but not as severe as the ENSO and IOD positive scenario.
• Heavy Rainfall: Moderate chances of heavy rainfall and flooding, mainly during the monsoon season.
• Cyclones: Slightly increased frequency and intensity of tropical cyclones making landfall in Bangladesh.
Justification:
• In this scenario, the positive ENSO phase (El Niño) can still contribute to drier and hotter conditions in Bangladesh, leading to an increased risk of heatwaves.
• However, the negative IOD phase can partially offset the effects of El Niño, resulting in a less pronounced impact on extreme weather patterns compared to the ENSO and IOD positive scenario.
• The combination of a positive ENSO and a negative IOD can still result in enhanced moisture transport towards South Asia, leading to moderately increased chances of heavy rainfall events and tropical cyclone activity in Bangladesh.
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(d) ENSO Negative, IOD Positive
Extreme Weather Conditions:
• Heatwaves: Reduced risk of severe heatwaves compared to the ENSO and IOD positive scenario.
• Heavy Rainfall: Increased chances of heavy rainfall and flooding, particularly during the monsoon season.
• Cyclones: Moderately increased frequency and intensity of tropical cyclones making landfall in Bangladesh.
Justification:
• In this scenario, the negative ENSO phase (La Niña) can contribute to cooler and wetter conditions in Bangladesh, reducing the risk of heatwaves.
• However, the positive IOD phase can partially offset the effects of La Niña, leading to enhanced moisture transport and convection towards South Asia.
• The combination of a negative ENSO and a positive IOD can result in increased chances of heavy rainfall events and a moderate increase in tropical cyclone activity in Bangladesh.
4 Images, This image captures a serene beach scene during sunset in Bangladesh. The sky is a dramatic mix of oranges and blues, with dark clouds gathering. The ocean waves gently wash onto the sandy shore, while palm trees line the coast. This scene reflects the natural beauty of Bangladesh’s coastal regions. The interplay of light and shadow adds depth to the landscape, making it an enticing view for anyone appreciating nature's artistry. It evokes feelings of peace and wonder at the power of nature
