Why in the News?
- A recent study shows that tropical cyclones passing over marine heatwaves become far more destructive, leading to about 60% more billion-dollar disasters due to rapid intensification.
What are Marine Heatwaves
- A prolonged period of unusually high sea surface temperature
- Duration: Days to months
- Temperature anomaly: Typically 1°C to 3°C above normal
Key Characteristics
- Region-specific phenomenon
- Defined by: Duration, Intensity, and Spatial extent
Causes of Marine Heatwaves
1. Climate Change
- Oceans absorb over 90% of excess heat
- Raises baseline temperature
2. Weakening Winds
- Less: Evaporation and Vertical mixing
3. Ocean Stratification
- Warm water trapped at surface
- No mixing with cooler deep water
4. Ocean Currents
- Transport warm water to new regions
5. Climate Oscillations
- Example: El Niño
- Raises sea surface temperatures
| [2020] With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct? 1 OMT is measured up to a depth of 26°C isotherm which is 129 meters in the southwestern Indian Ocean during January — March. 2 OMT collected during January – March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean. Select the correct answer using the code given below: a) 1 only b) 2 only c) Both 1 and 2 d) Neither 1 nor 2 |
