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Fog episodes in Indo-Gangetic Plains more intense and frequent
The Indo-Gangetic Plain (IGP), home to over 900 million people, has experienced a marked rise in air pollution as well as winter fog episodes, the World Meteorological Organization (WMO) said on Friday. Although fog is a seasonal occurrence, the WMO said its growing frequency and duration are increasingly linked to ever-increasing human activities and regional environmental changes.
Fog forms when air near the ground cools to the dew point, allowing moisture to condense on certain airborne particles [known as 'fog condensation nuclei' (FCN)] and form tiny droplets. This process is heavily influenced by fine particles (PM2.5) in the atmosphere, released from sources such as tail-pipe emission, industrial flue gas and burning of crop residue, fossil fuel and domestic biomass.
These FCN cause more persistent and dense fog formation. During winter, temperature inversions, where cold air becomes trapped beneath a layer of warmer air, lock pollutants near the ground, thereby extending the duration of fog events, the WMO said in its latest air quality and climate bulletin. It said that mushrooming of urban areas within the IGP has led to enhanced emissions and to the development of urban heat islands, altering local weather dynamics.
Sources of emissions include vehicles and construction. Another source is ammonium emitted from large cattle populations and poor sanitation facilities. When this ammonium interacts with other chemicals in the atmosphere, stable FCNs are formed. This, in turn, results in persistent fog, the WMO's bulletin said.
The UN weather and climate agency said that many brick kilns, using inferior coal and obsolete technology, further increase organic aerosol emissions. One dominant seasonal contributor to emissions is the burning of post-monsoon agricultural residue, particularly in Punjab and Haryana.
Satellite data confirm sharp increases in aerosol optical depth during these months, correlating with spikes in fog intensity all along the IGP, it said.
The interaction of fog droplets with aerosols also alters aerosol chemistry, with consequences for both climate and pollution.
Poor visibility during fog episodes impacts transportation, causing delays and accidents. Fog also causes severe health conditions such as asthma, bronchitis and other respiratory ailments. Elevated levels of toxic metals and organic compounds in fog water are a public health concern, the WMO said.
Pak, China launch second phase of CPEC, ink USD 8.5 bn deals
Pakistan and China have formally launched the second phase of the controversial CPEC project and signed 21 agreements and joint ventures worth about $ 8.5 billion. The MoUs were signed in Beijing on Thursday, on the concluding day of Prime Minister Shehbaz Sharif's visit to China, when he met with Chinese Premier Li Qiang and attended an investors' conference. According to the Dawn newspaper on Friday, the agreements covered cooperation in the development of China-Pakistan Economic Corridor (CPEC) 2.0, as well as in areas like science and technology, information technology, media, investment, and agriculture.
India opposes the CPEC, which will link Xinjiang in China and the Gwadar port in Pakistan's Balochistan, as it passes through Pakistan-occupied Kashmir (PoK). The CPEC is the flagship project of China's ambitious multi-billion-dollar Belt and Road Initiative (BRI).
The BRI is seen as an attempt by Beijing to further its influence abroad with infrastructure projects funded by Chinese investments all over the world.
Warming temperatures can impact animals' reproduction, survival: Studies
Two studies have found that extreme temperatures can change how a species reproduces, with one reptilian species becoming more resilient to climate change, while the other displaying a 'sex reversal' with a biological male growing into a functional female. Findings highlight that temperature not only impacts climate, but can also change how life is propagated, having profound implications for an increasingly warmer future, researchers said.
The team, including researchers from the Autonomous University of Barcelona in Spain, said that driven by human activity in the form of contamination and climate change, including greenhouse gas emissions and extreme temperatures, biodiversity is disappearing at an alarming rate.
However, how the changing environment directly affects reproduction and survival of species is not clearly known, they said. One of the studies, published in PLOS Genetics, looked at the Guibe's ground gecko -- a lizard species native to the warm ecosystems of Madagascar in Africa. The researchers found that in extremely hot conditions, the lizard species showed an increase in 'recombination' -- a process which creates genetic diversity and heightens a species' chances of adapting to a changing climate and, therefore, is fundamental for the propagation of a living being.
The Guibe's ground gecko (scientific name 'Paroedura guibeae') also displayed a greater DNA fragmentation and changes in chromosomal structures, revealing that temperature not only affects gene expression -- behaviour of a species resulting from how its genes interact with the surrounding environment -- but also how information in genes is passed on through generations. "This study helps us understand that global warming not only affects the climate, but also influences the adaptation mechanisms of animals to survive," co-author Laura Gonzalez Rodelas, a researcher from the Autonomous University of Barcelona, said.
Longest total lunar eclipse since 2022 to be visible acrossIndia on Sep 7-8: Astronomers
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The longest total lunar eclipse visible from India since 2022 will occur on the intervening night of September 7 and 8, astronomers said. They added that this is the first time since July 27, 2018, that an entire total lunar eclipse can be observed from all parts of the country. “You will have to wait till December 31, 2028, for the next one,” said Divya Oberoi, chair of the Public Outreach & Education Committee (POEC) of the Astronomical Society of India (ASI) and Associate Professor at the National Centre for Radio Astrophysics, Pune.
Eclipses are rare and do not occur every full or new moon because the Moon's orbit is inclined about 5 degrees to the Earth's orbit around the Sun, Oberoi explained. A lunar eclipse occurs when the Earth comes between the Sun and the Moon, casting its shadow on the lunar surface. The penumbral eclipse will begin at 8.58 pm on September 7, according to a press note issued by POEC. “The inner dark shadow of the Earth is called the umbra, and the faint outer shadow is the penumbra. As the Moon enters the umbra, we first see a partial eclipse,” Oberoi said.
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