Q. Why is this in news?
A new study on variability in the Mascarene High (MH) in the Southern Indian Ocean during global warming hiatus (GWH) has revealed that the region experienced significantly increased sea surface temperature (SST) during this period (1998-2016).
Q. What is Global Warming Hiatus (GWH)?
- A global warming hiatus is referred to a global warming pause, or a global warming slowdown, which is a period of relatively little change in globally averaged surface temperatures.
- The hiatus, however, can result in an increase in the SST.
Q. What is Mascarene High (MH)?
- The Mascarene High (MH) is a semi-permanent subtropical high-pressure zone in the South Indian Ocean.
- It is also called the Indian Ocean subtropical high, which is a high-pressure area located between 20° to 35° South latitude and 40° to 90° East longitude.
- It is a region from where the cross-equatorial winds blow to India.
- It has been named after the Mascarene Islands, in the Indian Ocean east of Madagascar consisting of the islands belonging to Mauritius as well as the French Réunion Islands.
- Apart from its large influence on African and Australian weather patterns, it also helps in driving the inter-hemispheric circulation between the Indian Ocean in the south and subcontinental landmass in the north.
Q. What is the role of Mascarene High?
- The warming in SST due to global warming has resulted in a decrease in the pressure gradient between the MH and the Indian landmass.
- This in turn suppressed the intensity of low-level cross-equatorial winds over the western Indian Ocean affecting the onset of the monsoon over the Indian subcontinent and rainfall over East Asia.