‘Landfall’ of a cyclone

GS Paper - 1 (Geography)

The landfall process of Cyclone Biparjoy started near Jakhau port in the state’s Kutch district, according to the India Meteorological Department (IMD). The cyclone crossed Saurashtra & Kutch and adjoining Pakistan coasts between Mandvi (Gujarat) and Karachi (Pakistan).

What is the “landfall” of a cyclone?

• Simply put, landfall is the event of a tropical cyclone coming onto land after being over water. As per the IMD, a tropical cyclone is said to have made a landfall when the center of the storm – or its eye – moves over the coast.
• Crucially a landfall should not be confused with a ‘direct hit’, which refers to a situation where the core of high winds (or eyewall) comes onshore but the centre of the storm may remain offshore.
• As per the US’s National Oceanic and Atmospheric Administration (NOAA), because the strongest winds in a tropical cyclone are not located precisely at the centre, it is possible for a cyclone’s strongest winds to be experienced over land even if landfall does not occur.

What is the damage caused by a cyclone’s landfall?

• The damage caused by the landfall will depend on the severity of the cyclone – marked by the speed of its winds.
• For Cyclone Biparjoy, classified by the IMD as a “very severe cyclonic storm”, the impact may include extensive damage to kutcha houses, partial disruption of power and communication lines, minor disruption of rail and road traffic, potential threat from flying debris and flooding of escape routes.
• The factors behind this kind of damage include extremely strong winds, heavy rainfall and the storm surge which cause devastating floods in the coast.

How long does a landfall last?

• Landfalls can last for a few hours, with their exact duration depending on the speed of the winds and the size of the storm system.
• Cyclone Biparjoy’s land process is expected to last around five to six hours, with the cyclone almost completely dissipating over approximately the next 24 hours.
• Cyclones lose their intensity once they move over land because of sharp reduction of moisture supply and increase in surface friction.
• This means that while landfalls are often the most devastating moments of cyclones, they also mark the beginning of its end.

El Nino impacts the monsoon

GS Paper - 1 (Geography)

This year’s monsoon is also progressing under the cloud of an El Nino in the Pacific Ocean. El Nino, as is commonly known, refers to an abnormal warming of surface waters in equatorial Pacific Ocean. It is known to suppress monsoon rainfall. The opposite phase, La Nina, which is the abnormal cooling of sea surface waters in the same region, is known to aid rainfall over India. There is a third, neutral phase, as well in which the sea surface temperatures remain roughly in line with long-term averages. Together, these three phases in the Pacific Ocean are referred to as El Nino Southern Oscillation, or ENSO.

Ocean-Atmosphere system

• Though ENSO is mostly discussed in terms of temperature abnormalities of sea surface waters, it is important to understand that it is not just an ocean system.
• ENSO actually is an interaction of ocean and atmospheric conditions. In fact, the ‘southern oscillation’ part in the term ENSO refers to a specific atmospheric condition that is a measure of the difference in sea-level air pressure over western and eastern side of the Pacific Ocean.
• Another atmospheric condition that plays a key role in ENSO is the strength and direction of winds.
• Just the abnormal warming or cooling of surface waters in the Pacific Ocean does not result in an El Nino or La Nina event.
• The associated atmospheric conditions also have to be sync. The ocean part of the ENSO is measured by what is known as the Oceanic Nino Index or ONI. The atmospheric part is monitored through Southern Oscillation Index, or SOI.
• The ocean and atmospheric conditions in El Nino or La Nina tend to reinforce each other, producing a cyclic process.
• That means that the warming of the sea surface waters during an El Nino event influences atmospheric conditions in a way that these, in turn, result in further warming of the waters.
• Similar processes happen during the La Nina event as well. The linkages between waters and wind were unveiled in the 1960s.
• The playground of this entire system is the equatorial region in the Pacific Ocean. On the east are Ecuador and Peru in northwestern South America and on the west are the islands of Philippines and Indonesia.
• Between them is nearly17,000 km of uninterrupted ocean. This region receives the most sunlight anywhere on earth, a lot of which is stored as heat in the ocean.

Species with ‘objectionable’ scientific names

GS Paper - 3 (Science and Technology)

In recent years, the field of taxonomy, the science of naming and classifying all living beings, has been witnessing a raging debate — whether species with objectionable scientific names should be renamed. These are names largely taken from problematic people, such as those linked to slavery and racism, or are linked to derogatory terms and racial slurs. 

Why is it mainstream?

• Although such discussions have always existed, they became mainstream only recently, especially after the emergence of Black Lives Matter (2013-present) in the USA.
• The movement, which highlights police brutality and systematic racism against Black people, also focuses on efforts to remove statues of slave traders, anti-abolitionists and White supremacists and rename institutions and facilities named after such people.

What are some of the species with problematic names?

• The best known example of such a living being is Anophthalmus hitleri. Named after the former German Führer, Adolf Hitler, this rare blind beetle, popularly known as the Hitler beetle, was discovered in 1933 by “Oscar Scheibel, a German amateur entomologist and ardent Hitler fan, and is found in only around 15 caves in central Slovenia.,”
• The Independent said in a 2006 report. It also noted that although the insect was initially shunned away by scientists as it didn’t have any special attributes, it gained widespread prominence among Neo-Nazis in the later years.
• The popularity of the Hitler beetle touched such heights that it became nearly extinct. The Independent report quoted a beetle expert saying: “There is a complete run on these creatures, and collectors are intruding on the beetles’ natural habitat to get hold of them.”
• Another example is the common small-blotched lizard. With the scientific name Uta stansburiana, the reptile, in 1852, was named after Howard Stansbury, who led a famous expedition to study the flora and fauna in the USA’s Utah region and collected this lizard’s type specimens.
• Among the species which have been named after derogatory terms is the Hottentotta tamulus scorpion — “colonialists in the 17th century used “Hottentot” as a derogatory term for Indigenous Black people in Africa.

How are species given their scientific names?

• Every species of animal or plant has two scientific names. The first name denotes the genus to which the species belongs.
• It is a generic name and is always capitalised. The second name identifies the species within the genus and is never capitalised. Both names are italicised.
• A genus may comprise several closely related species. Thus many large hawks are placed in the genus Buteo… Just as closely related species are placed in the same genus, closely related genera (the plural of “genus”) are grouped into a family. Jaguars, tigers, and house cats all belong to the family Felidae.