An international study taken up under the aegis of IIT M researchers found that Chloride rich particles were responsible for low visibility in New Delhi.

It is known that low visibility levels in national capital has been causing much concern for quite sometime now.

The study conducted by IIT M researchers has been published in a prestigious peer-reviewed International Journal Nature Geoscience.

A video featuring Dr. Sachin Gunthe of IIT Madras explaining the important findings of the study by IIT M researchers has been made.

IIT M researchers find great cause behind low visibility in Delhi

The video is available on the link ‘https://fromsmash.com/Delhi-Pollution’

Studies have been taken up not only by IIT M researchers but also by many others in the past.

Those in the past have identified identified PM2.5 (particulate matter or aerosol particles with diameter less than 2.5 micrometre) as a major pollutant, responsible for haze and fog formation over Indo-Gangetic plain including Delhi.

However, the role of PM2.5 and detailed chemistry of haze and fog formation over national capital was poorly understood.

Such a lack of understanding was the biggest hurdle in developing the policies to improve the air quality and visibility.

The study by IIT M researchers greatly enhances the understanding about the precise role of PM2.5 in Chemistry of fog formation, which will help policy makers to frame better policies for improving the air quality and visibility over national capital.

With the approaching winter season, every year, most of the Indo Gangetic Plain invariably is engulfed in a dense fog and haze, particularly during the months of December and January.

Over the national capital dense fog negatively impacts the air and surface transport resulting in huge financial losses and jeopardise human lives.

Overall life comes to standstill during the dense fog, say IIT M researchers.

The study by IIT M researchers not only provides the scientific explanation for source of high chloride in PM2.5 mass over Delhi but also quantifies its role in haze and fog formation and visibility reduction.

While previous researchers also have observed high chloride in PM2.5, the potential source of such a high chloride and if it played any role in haze and fog formation was a scientific mystery.

The study was conducted by IIT M researchers in collaboration with Max Planck Institute for Chemistry of Germany, Harvard University of USA, Georgia Institute of Technology (USA) and Machester University of UK.

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IIT M researchers and others deployed state-of-the-art instruments to measure the chemical composition and other important properties of PM2.5, along with relative humidity and temperature in Delhi, which were operated round the clock for one month with extreme care and dedicated expertise.

The observations were then used in complex chemical models.

The findings were surprising for IIT M researchers and others and they unfolded the mystery of high chloride in PM2.5 and scientifically unravelled its precise role in fog and haze formation over Delhi.

‘If overall PM2.5 mass burden over Delhi is much lower than polluted megacity Beijing, then why visibility reduction is major problem in Delhi?’ He asked.

Speaking further on the study taken up by IIT M researchers, Dr. Sachin Gunthe said he real challenge was to delineate the role of high chloride in visibility reduction.

The resolution of the mechanism was derived with the collaborative effort from all the partners in this project with various tools of analysis.

This study by IIT M researchers is a demonstration of a successful large scale scientific collaborations that are so vital for climate studies, said Dr. Sachin.

Speaking more about the study by IIT M researchers and others Professor R. Ravikrishna of Department of Chemical Engineering at IIT Madras said with the results from first couple of days, it was very clear to us that Delhi is different.

Generally for a polluted urban region like Delhi, one would expect sulfate to be highest inorganic fraction of particulate matter, said Professor Ravikrishna, who is also a part of IIT M researchers.

However, we found chloride to be the highest inorganic fraction of particulate matter, he said.

The HCl from various sources combines with ammonia, which is emitted in great amounts over this region.

Thus, ammonium chloride (NH4Cl) so formed condenses to aerosol and exponentially increase the water uptake ability of aerosol particles resulting increase in size, eventually leading to dense fog formation, say IIT M researchers.

In the absence of the excess chloride, the fog formation otherwise would be suppressed significantly.

Enhancement in understanding of water uptake by particles in Delhi is of enormous significance as very poor visibility over this region leads to financial burden and loss of human lives.

Further, not only this study by IIT M researchers emphasises plastic burning emits toxic substances in the atmosphere impacting human health but also these emissions are for the first time linked to visibility and climate.

Speaking about the findings of the study by IIT M researchers, Dr. Sachin said scientifically their job is half-done.

Plastic-contained waste burning can emit highly toxic chemicals called ‘dioxins’, which can accumulate in food chain causing severe problems with reproduction and immune system, said Dr. Sachin who led IIT M researchers.

We further need to investigate in this direction. Enhancement in fundamental science of air pollution should be given importance as much as technology development to tackle pollution, said Dr. Sachin.

The study by IIT M researchers identifies waste burning as a major pollutant source, which is responsible for emissions of aerosol precursors as well as other toxic substances such as chlorinated dioxins and other persistent pollutants that affect human health.

The study by IIT M researchers also emphasised need to improve the policies related to air pollution, solid waste management including e-waste, and food safety to systematically address the environmental issues in India.

The schedule to submit applications for JEE Advanced 2025 has been announced along with that of AAT 2025 registration,

Application process for AAT starts after result declaration of JEE Advanced. This year too, the trend is no different.

Who will conduct AAT 2025?

AAT 2025 will be conducted by IIT Kanpur and is expected to see a participation in impressive numbers. The same institution is conducting JEE Advanced 2025.

Details about the exam are available on the official website mentioned above. Students who pass AAT 2025 will be able to study BArch in IIT Roorkee, IIT Kharagpur and IIT (BHU) Varnasi.

Who can take up AAT 2025 registration?

Students who have passed JEE Advanced 2025 with required qualifying marks can take up AAT 2025 registration. Applying for JEE Advanced requires a pass in JEE Mains.

Candidates who have passed plus two with maths, physics and chemistry as subjects will be able to take up JEE Mains registration. The process to take up JEE Advanced AAT 2025 registration is online.

1. The URL has to be typed into the browser and the webpage has to be allowed to download.

2. Once the website is available, students should click the link for JEE Advanced AAT 2025 registration and enter JEE Advanced 2025 registration number, their date of birth, mobile number and email address.

3. Post providing the above details, applicants will be asked if they are interested in AAT. Students have to answer ‘Yes’ to take up JEE Advanced AAT 2025 registration.

4. Candidates have to provide the required information and choose the centers where they wish to write the exam and submit the form.

5. They will receive message indicating successful completion of JEE Advanced AAT 2025 registration.

The message has to be downloaded and a printout of it has to be taken and preserved for use in future. This could be of use during the admission process.

Website for JEE Advanced 2025/AAT 2025 Registration is Here

Exam pattern

Candidates who have completed JEE Advanced AAT 2025 registration must also know the exam pattern if they are to score good marks.

Those who have taken up AAT 2025 registration can take up the exam which will be held in offline mode, as a pen and paper mode test.

Candidates will have three hours time to answer all the questions. The medium of the test is English.

The sections in the question paper are – Imagination and aesthetic sensitivity, three dimensional perception, Geometrical drawing, Freehand drawing and Architectural Awareness.

Syllabus for AAT 2025

The next thing to do after completing AAT 2025 registration is focus on preparing for the test.

The subjects to be studied while preparing for AAT 2025 are mentioned below. Candidates can also refer the official website for more information on syllabus when the registration for the exam begins:

Geometrical Drawing

Exercises in geometrical drawing containing lines, angles, triangles, quadrilaterals, polygons, circles, etc. Study of plan (top view), elevation (front or side views) of simple solid objects like prisms, cones, cylinders, cubes, splayed surface holders, etc.

Freehand Drawing

This would comprise of simple drawing depicting the total object in its right form and proportion, surface texture, relative location and details of its component parts in appropriate scale.

Common domestic or day-to-day life usable objects like furniture, equipment, etc., from memory.

Three dimension perception

Understanding and appreciation of three-dimensional forms with building elements, colour, volume and orientation. Visualization through structuring objects in memory.

Architectural Awareness

General interest and awareness of famous architectural creations – both national and international, places and personalities (architects, designers, etc.) in the related domain.

Imagination and Aesthetic Sensitivity

Composition exercise with given elements. Context mapping.

Creativity check through innovative uncommon test with familiar objects. Sense of colour grouping or application.

The medium of the test is English. The sections in the question paper are – Imagination and aesthetic sensitivity, three dimensional perception, Geometrical drawing, Freehand drawing and Architectural Awareness.

The admit cards obtained for JEE Advanced 2025 can also be used to gain entry into the test centers for AAT 2024.

Point to remember

Candidates can visit the official website of JEE Advanced exam for more information on JEE Advanced AAT 2025 registration and other related topics.

The students have to quickly take up the AAT 2025 registration as the time left would be very short.

Like JEE Advanced exam where the registration is open for a longer duration, that of AAT 2025 registration is open for only a short period.

The details about AAT 2025 registration provided above are for general understanding purpose of the students.

There could be some changes in the exam, students can visit the official website of the exam at regular intervals to receive updates.

More information could be provided as the time for AAT 2025 registration would commence, till that time, students can refer other sources also.

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