World Tour of COVID-19 Impacts on Nighttime Lights by Christopher D. Elvidge Feng-Chi Hsu, Tilottama Ghosh, Mikhail Zhizhin Earth Observation Group Payne Institute for Public Policy Colorado School of Mines April 21, 2020
World Tour of COVID-19 Impacts on
Nighttime Lights
by Christopher D. Elvidge
Feng-Chi Hsu, Tilottama Ghosh, Mikhail Zhizhin
Earth Observation Group
Payne Institute for Public Policy
Colorado School of Mines
April 21, 2020
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Is it possible that lockdowns designed to constrain COVID-19
infection rates have dimmed electric lighting? The dimming may have
already been recorded by the NASA / NOAA Visible Infrared Imaging
Radiometer Suite (VIIRS) day / night band (DNB). To examine this
question we calculated changes in the brightness between monthly
cloud-free average radiance composites. For China we studied two
matched monthly pairs – one pre-pandemic and the other straddling
the pandemic lockdown. The pre-pandemic pair was December 2018
minus March 2019. The pair straddling the pandemic lockdown was
December 2019 minus February 2020. We found lighting had dimmed
in many parts of China in February 2020 – the peak of the pandemic.
Then we repeated the analysis globally using February 2020 minus
March 2020.
Background
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February, 2020
Cloud-free composite
December 2018
minus March 2019
Red = lighting dimmed
Cyan = lighting brightened
December 2019
minus February 2020
Red = lighting dimmed
Cyan = lighting brightened
Beijing, ChinaLighting dimmed in February 2020
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Beijing, ChinaFebruary 2020 minus March 2020
Lighting has largely recovered!Red = lighting dimmed. Cyan = lighting brightened.
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New York City RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Washington, D.C. RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Atlanta RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Miami, Florida RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Chicago RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Denver, Colorado RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Las Vegas, Nevada RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Phoenix, Arizona RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Los Angeles RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Sao Paulo, Brazil RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Tokyo RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Tehran, Iran RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Baghdad, Iraq RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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London, England RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Paris, France RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Milan, Italy RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
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Delhi, India RegionFebruary 2020 minus March 2020
Red = lighting dimmed. Cyan = lighting brightened.
Summary
• The VIIRS day / night band (DNB) records the location and brightness of electric lighting worldwide.
• The Earth Observation Group makes monthly global cloud and moon free average radiance products from
DNB data.
• By subtracting one month from another it is possible to identify area where lighting either dimmed or
brightened.
• In China we compared image difference pairs from before the pandemic (December 2018 minus March 2019)
and a second pair straddling the lockdown (December 2019 minus February 2020). We found lighting had
declined in many parts of China in February 2020.
• Then we made a global image of February 2020 minus March 2020.
– Lighting had recovered in many parts of China.
– In the USA lighting declined in states having lockdown edicts, such as New York, California, Colorado.
– No substantial decline was found in several states lacking lockdown edicts, such as Florida and Arizona.
– India had substantial dimming.
– London had dimming but many nearby cities did not.
– Paris has a rectangular dimming block near it’s center.
– Dimming was patchy in Italy and Japan.
– Brazil and Iraq largely lacked dimming.
• The results indicate that the dimming is associated with government lockdown edicts and that lighting can
rebound relatively quickly when businesses are allowed to reopen.
• It should be possible to use this methodology to monitor the return of normal activity levels as the virus
disruptions dissipate.
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