Blue Skies, Breathable Air, Delhi's AQI Drops to 45 as People Stays Home

Delhi woke up to clear blue skies yet again on Saturday As India remained under lockdown for the fourth consecutive day, the nation’s focus stayed on preventing the spread of Covid-19 infections and helping stranded citizens. Meanwhile, an unprecedented change was in the air, literally. With steep decline in traffic volumes, construction and industrial activity, India on Saturday recorded the best air quality in years, if not decades.

New Delhi typically has some of the most polluted air in the world. But amid India’s lockdown — which ordered 1.3 billion people to stay home — residents are posting pictures of clear blue skies.https://t.co/7uV2JdMHyq

— NPR (@NPR) April 10, 2020

Delhi recorded its best ever AQI of 45 on Saturday, a day after a spell of rain. This was the first “good air” day in the capital since August 18 last year and only the third in more than three years. This was also the first time that the capital recorded AQI in the “good” range outside the monsoon months. An average AQI of 45 has never been achieved in Delhi since the air quality index was launched. March is a month of weather transition. An AQI in the ‘good’ range is unheard of in Delhi during this month,” said Dipankar Saha, former head of CPCB’s air lab.
Improvement in air quality was seen across Indian cities, a trend clearly linked to the national lockdown.

AQI- Statistics

The AQI, which is maintained by the Central Pollution Control Board (CPCB), recorded a ‘Satisfactory’ reading of 50 in Delhi’s Indira Gandhi International Airport on Friday. According to CPCB data, this was the lowest in months. The same area had regularly recorded numbers above 300 in February of this year.

Air pollution plunges in India with smog-hit Delhi seeing blue skies as coronavirus lockdown continues https://t.co/vZEq5gs1p7

— Daily Mail Online (@MailOnline) March 31, 2020

The R.K Puram area of Delhi saw the AQI drop even further to 46 on Friday, according to the World Air Quality Project which aggregates data from several sources such as the Indian Meteorological Department and CPCB. As per the categorization of the CPCB, 46 qualified as ‘Good’.
Other areas were the AQI reaching above 200 is common also saw the AQI drop to below ‘Satisfactory’ levels. In Anand Vihar, the AQI was 70 while in Dwarka the AQI was 80. AQI numbers above 100 are considered unsatisfactory and hazardous to health according to CPCB classification.
However, some areas of the National Capital still have AQI figures above hundred. According to CPCB, Bawana area of Delhi has AQI of 113 which is ‘unsatisfactory’. While, Siri Fort, Delhi recorded an AQI of 135.
Neighboring city Noida also saw its AQI drop to ‘Satisfactory’ levels. The AQI of Noida’s Sector 62 was 65 according to the CPCB as of 8:00 am on Friday.
The entire country has been put under a 21-day lockdown as a measure to curb the spread of the corona virus. With fewer cars on the street, and even fewer factories running, the air quality of Delhi has significantly improved in just the first three days of the lockdown.

Clear Blue Skies- An Eye Candy for Delhiites

In just two weeks, the rivers are cleaner, the air is less polluted, the skies are blue, the wildlife is out on the streets.

Who is the real virus? pic.twitter.com/Zlk4xp9rSK

— Anand Ranganathan (@ARanganathan72) April 6, 2020

Clear blue skies have become the norm rather than the exception in the National Capital Region (NCR) around Delhi for the past week. Data, too, shows a sharp decline in pollution.

The reduction in nitrogen dioxide (NO2) concentrations is even more pronounced because the major source of NO2 emissions are vehicles , which have gone off the roads, and industries, which have been ordered to close to reduce the risk of infection.

The hourly pollution trend in Delhi and in the neighbouring cities of Gurugram, Faridabad, Noida and Ghaziabad analyzed by CSE used to be influenced by traffic peaks in the mornings and evenings, a factor hasn’t been relevant in the past four days.

For example, in Delhi the daily peak PM 2.5 concentrations has declined on a lockdown day by about 57% compared to a regular day and the peak on the “Janta Curfew” day (Sunday, March 22) dropped by about 24% compared to a regular day. The peak concentrations of NO2 dropped by 66% on a lockdown day compared to a regular day and by 32% on the people’s curfew day.

The so-called Janta Curfew was called for by Prime Minister Narendra Modi as a sort of a trial in social distancing and self-isolation. The lockdown was announced two days later.

Globally, four million new child asthma cases are attributable to NO2 pollution a year; 64% of these occur in urban centres, according to a study published in Lancet Planetary Health.

“This experience has helped us to understand the strong impact of traffic volume on hourly variability in pollution and exposure in cities. We are already making massive lifestyle adjustments to practice social distancing,” said Anumita Roy Chowdhury, executive director, Centre for Science and Environment.

“Since every source of emissions is curtailed, air pollution levels have reduced drastically in Delhi-NCR.

In a time marked by fear and worry, people in Delhi are treasuring an unintended consequence of the world’s largest lockdown: clean air. https://t.co/2JNTqIUH4r

— Joanna Slater (@jslaternyc) April 11, 2020

Clear skies and less noise means that bird song can be heard clearly in many neighbourhoods of the capital. There are a lot of people hovering around, asking, if bird song has increased. No, it has always been there particularly in this season. This is also the courting and nesting season for many birds — sunbirds, barbets and doves. So they sing or call for long periods. People now have the time to pause, listen and take in the song. The lack of planes and cars also helps as planes and car horns are sources of noise pollution.