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On March 24, 2020, Prime Minister Modi ordered a nationwide stay-at-home order for India’s 1.3 billion citizens in an attempt to slow the spread of COVID-19.
This visualization, created using data from the Ozone Monitoring Instrument (OMI) onboard NASA’s Aura satellite, shows annual, average changes in sulfur dioxide concentrations from 2005 to 2017. Sulfur dioxide concentrations from volcanic (i.e., natural) sources have been removed.
Sulfur dioxide is produced by the combustion of coal, fuel oil, and gasoline (since these fuels contain sulfur), and in the oxidation of naturally occurring sulfur gases, such as in volcanic eruptions. The largest source of sulfur dioxide in the atmosphere is the burning of fossil fuels by power plants and other industrial facilities. National and regional rules to reduce emissions of sulfur dioxide can improve air quality.
This visualization, created using data from the Ozone Monitoring Instrument (OMI) onboard NASA’s Aura satellite, shows annual, average changes in sulfur dioxide concentrations from 2005 to 2017. Sulfur dioxide concentrations from volcanic (i.e., natural) sources have been removed.
Sulfur dioxide is produced by the combustion of coal, fuel oil, and gasoline (since these fuels contain sulfur), and in the oxidation of naturally occurring sulfur gases, such as in volcanic eruptions. The largest source of sulfur dioxide in the atmosphere is the burning of fossil fuels by power plants and other industrial facilities. National and regional rules to reduce emissions of sulfur dioxide can improve air quality.
Scientists examined observations made from 2005 to 2014 by the Ozone Monitoring Instrument aboard NASA's Aura satellite. One of the atmospheric gases the instrument detects is nitrogen dioxide, a yellow-brown gas that is a common emission from cars, power plants and industrial activity. Nitrogen dioxide can quickly transform into ground-level ozone, a major respiratory pollutant in urban smog. Nitrogen dioxide hotspots, used as an indicator of general air quality, occur over most major cities in developed and developing nations.
The following visualizations include two types of data. The absolute concentrations show the concentration of tropospheric nitrogen dioxide, with blue and green colors denoting lower concentrations and orange and red areas indicating higher concentrations.
The second type of data is the trend data from 2005 to 2014, which shows the observed change in concentration over the ten-year period. Blue indicated an observed decrease in nitrogen dioxide, and orange indicates an observed increase. Please note that the range on the color bars (text is in white) changes from location to location in order to highlight features seen in the different geographic regions.
For nearly 25 years, satellite images of Earth at night have served as a fundamental research tool, while also stoking public curiosity. These images paint an expansive and revealing picture, showing how natural phenomena light up the darkness and how humans have illuminated and shaped the planet in profound ways since the invention of the light bulb 140 years ago.