Every year, fluctuations are observed in the #ozone hole due to variation in stratospheric temperatures—the second layer of Earth’s atmosphere. As per recent observations, this year’s ozone hole is recorded to be one of the largest & deepest, as compared to the last 15 years.
However, despite the alarming changes, not many scientists are concerned about any major impacts on #Earth, mainly because it appears to be just a seasonal phenomenon.
According to the European Space Agency (ESA), the ozone hole increases in size from August to October—every year—and reaches its maximum between mid-September and mid-October.
The ozone hole—not a typical hole, but a drop in thickness—is predominantly present at the southern hemisphere of the globe. The hole refers to a region of depleted ozone in the stratosphere—an atmospheric layer that extends from 10 km to 50 km altitude.
The depletion mainly happens when the temperature over the stratosphere starts to vary.
The polar vortex is a weather system responsible for delivering cold air to the Polar Regions and this year scientists have recorded it to be one of the strongest.
(Image credit: Robert Schwarz/University of Minnesota/NASA)
As per the World Meteorological Organisation (WMO), the polar stratospheric clouds formed over ozone can easily contribute to the chemical destruction of ozone when the temperature drops to -78°C.
The clouds contain ice crystals that can destroy the ozone when mixed with sunlight. This kick starts a chemical reaction, which turns non-reactive compounds in ozone into reactive ones.
The measurements of the present hole were obtained from the ESA’s Copernicus Sentinel-5P satellite, which revealed the size to be around 24 million sq km on October 2.
The 2019’s ozone hole, on the other hand, was recorded to be the smallest in the last 30 years. Last year, the hole reached its peak at 16. 4 million square kilometres on September 8, 2019, and then shrank to 10 million square kilometres for the rest of September and October 2019
As per the ESA, the variability of the ozone hole size is largely determined through the strength of a strong wind band around Antarctica. The strong wind band occurs due to Earth’s rotation and temperature difference between polar and moderate latitudes.
If this wind band is relatively strong, then the exchange of air masses between polar and latitudes can be restricted. Therefore, this keeps the polar latitudes isolated, indicating a strong polar vortex.
A significant widening of the ozone hole was observed by studies way back between the 1970s and 1980s, and the primary cause of this drastic depletion was identified as the significant increase in the use of damaging chlorofluorocarbons in products like refrigerators.
However, after the successful implementation of the Montreal Protocol, the use of such Ozone Depleting Substances has been brought under control.
Despite small spikes in usage once in a while, damage to #ozone due to human-made chemicals have largely been contained since the 2000s. The current variability, by and large, appears to be natural and a quick recovery is expected as the season changes.
Today, the Thar Desert, situated in the northwestern part of the country, is a barren desert with no trace of any moisture. But, 1,72,000 years ago, this Great Indian Desert hosted a brimming stream of a large river, says new research.
Evidence suggests that the lost river flowed through the central Thar Desert near Bikaner.
Geographically, the desert is located partly in Rajasthan, with its other part stretching towards eastern Pakistan in Sindh.
#SankeyTank | Karnataka Deputy Chief Minister C.N. Ashwatha Narayana on Thursday offered 'bagina' at Sankey tank which is filled to the brim and overflowing after a gap of 12 years.
"Bagina" is a kind of pooja offered to Goddess Gange, a Hindu ritual widely practiced in Karnataka, whenever tanks, lakes and rivers fill to the brim. Due to copious rains in the last fortnight, the Sankey tank filled up after more than a decade.
This iconic tank is situated in Malleshwaram constituency, which Narayana represents in the Assembly. The tank is also well known for its scenic beauty and it is a bird watchers paradise.
#Astronomy is regarded as the oldest of all sciences.
The ‘study’ of astronomy started when our predecessors realised that sunrise happens in one direction and sunset in the other, and that the Moon has a different shape (phase) each day.
-In that way, the sense of astronomy may even predate the invention of the wheel or control over fire.
Astronomy may even be older than the idea of language itself. The figure below shows a beautiful image, possibly of the Sun God, with indications of four seasons...
(📸: University of Queensland/Handout via Xinhua/IANS)
The #COVID19Vaccine developed by scientists at the #OxfordUniversity, which is currently in advanced stages of the trial, could be rolled out in as little as three months in the UK, a report said.
According to the Times, a mass roll-out of a #coronavirusvaccine could be completed in as little as three months, raising the prospect of every adult in the country receiving a jab as early as Easter.
Nothing can escape the powerful cosmic monster black holes—not even light—due to its strong gravitational pull that attracts nearly everything around the region.
Researchers have found that #GlobalWarming is driving an unprecedented rise in sea temperatures, including in the Mediterranean sea.
Data from the European Union's (EU) Copernicus Marine Environment Monitoring Service (CMEMS) will increase concerns about the threat to the world's seas and oceans from #climatechange.