Human-Induced Climate Change Could Increase ‘Medicanes’

  • Extra tropical storms in the Mediterranean Sea, known as ‘Medicanes’ or ‘Mediterranean Hurricanes’, could become more frequent due to human-induced climate change, experts have warned.
  • Recently, a medicane named Ianos made landfall along the coast of Greece and caused heavy rainfall and flooding on the islands of Zakynthos, Kefalonia and Ithaca.
  • The wind speeds reached upto 100 kilometres per hour (km / hr).
  • Scientists said medicanes are not as rare but might become more frequent owing to global warming due to anthropogenic climate change.
  • This might also mean an increased threat from these storms for already vulnerable populations living in North Africa, possibly triggering human migration.
  • They could also be a menace for European countries like Italy and Greece.
  • Medicanes occur more in colder waters than tropical cyclones, hurricanes and typhoons.
  • Hence, the cores of these storms are also cold, as compared to the warm cores of tropical cyclones.
  • Warmer cores tend to carry more moisture (hence rainfall), are bigger in size and have swifter winds.
  • Sometimes, warm-cored tropical cyclones transform into cold-cored extratropical cyclones and in rare cases, the opposite can also happen, according to the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).
  • The rare event of an extra tropical cyclone becoming a tropical cyclone happens because of warmer-than-usual waters in the Mediterranean Sea.
  • The Mediterranean is a generally dry, evaporative sea and cyclonic storms don’t grow as much rain and can be hard to detect.
  • They can occur anytime of the year but tend to peak during fall /winter months.
  • This year is a mild La Niña, according to the World Meteorological Organization.
  • La Niña is the cooling phase of the El Niño Southern Oscillation (ENSO) cycle in the equatorial Pacific Ocean, as opposed to the warming El Niño phase.
  • It is characterised by the unusual cooling of the central and east-central equatorial Pacific Ocean.
  • A La Niña produces more rain in the central eastern part, where most of the Mediterranean cyclones develop.
  • The slopes and the convection rising from sea waters can combine to spin off these cyclonic storms that become a Medicane if the 10-minute average wind speeds are greater than 99 km / hr.