Some interesting and unexpected facts.
While scientists around the world are confined to their homes during the COVID-19 pandemic, Earth observing satellites continue to orbit and send back images that reveal connections between the pandemic and the environment.
“Satellites collect data all the time and don’t require us to go out anywhere,” Hannah Kerner, an assistant research professor at the University of Maryland in College Park, said.
She is among eight researchers recently awarded a rapid-turnaround project grant, which supports investigators as they explore how COVID-19 stay-at-home measures are impacting the environment and how the environment can affect how the virus is spread.
The newest group of projects includes six that are looking to satellite images to help reveal how COVID-19 stay-at-home measures are impacting food security, fire ecology, urban surface heat, clouds and warming, air pollution and precipitation, and water quality and aquatic ecosystems. Two projects are exploring how the environment could be impacting how the virus is spread by monitoring dust and weather.
NASA’s Earth Science Division manages these projects that find new ways to use Earth observing data to better understand regional-to-global environmental, economic, and societal impacts of the COVID-19 pandemic.
Fewer Cars Might Mean Hotter Surfaces
“It suddenly got so quiet,” Potter said, “There was no traffic anywhere in late March and April.”
Potter and his team are monitoring parking lots and other surfaces to see if they are hotter or cooler during the pandemic. Visible light from the sun hits the surface and then is absorbed and reradiated as heat – a process called thermal heat flux.
The team is using satellite thermal infrared sensor brightness temperatures from Landsat and land surface temperature from ECOSTRESS, which is a NASA sensor on the International Space Station, to map out large, flat urban features in the Bay Area and measure their thermal heat flux. He’s also gathering on-the-ground measurements to ground truth the data.
Potter is asking questions like, if automobiles are parked and concentrated in giant lots, do you change the reflectance of the surface and the overall heat flux? Even shiny car windows may be enough to reflect sunlight, Potter said.
Potter and his team want to know how the entire Bay Area’s urban heat flux has changed during the pandemic, and how that change has contributed to a more or less healthy environment for the millions of people living in it. Understanding potential changes in the thermal heat flux is a key indicator of how COVID-19 has altered the Bay Area’s environmental footprint, Potter said.
In response to COVID-19 travel bans and stay-at-home policies, we’re flying a lot less and producing fewer contrails.
The team is using an established contrail detection algorithm to estimate coverage over the contiguous United States and the North Atlantic air traffic corridor over the 2020 slowdown period and compare that to a baseline period a couple years earlier when air traffic was unrestricted. Duda and Smith are also using MODIS to determine contrail optical properties to better understand how they reflect sunlight and trap energy from the surface and atmosphere below them.
Improving our understanding of how and when contrails form could help scientists inform airlines on ideal routes to fly planes. “It might be possible to reduce contrails and their effects by making occasional flight altitude or routing adjustments much like the airlines do now to avoid turbulence,” Smith said.
Less Air Pollution May Mean Less Rain
Gabriele Villarini, a professor at the University of Iowa in Iowa City, and Wei Zhang, a scientist in the same institute, want to understand the connection between reduced air pollution during the pandemic and sharp decreases in precipitation in the western U.S.
Moisture in the atmosphere condenses around aerosols, or particles like dust, and falls to Earth as rain and snow. Fewer aerosols during the pandemic may have been responsible for the reduced precipitation in February and March 2020 across the western U.S., with areas receiving less than 50% compared to a typical year. Understanding how the decrease in precipitation is related to reduced aerosols could be valuable to water resource managers.
Villarini is aiming to use NASA’s satellite data on water vapor, precipitation, and aerosols as well as a comprehensive climate model that can combine atmospheric conditions such as moisture and temperature with chemical properties and processes that take place in the atmosphere. The model will help his team pinpoint the extent to which the reduction in aerosols is responsible for the decrease in precipitation as opposed to the natural variability in the climate system.
“This project will help us understand how COVID-19 is impacting the natural environment,” Villarini said.
Finding a Human Imprint on Water Quality in Belize
The coastal area of Belize includes the largest barrier reef in the Northern Hemisphere, offshore atolls, several hundred sand cays, mangrove forests, coastal lagoons, and estuaries. It is one of the most biodiverse ecosystems in the Atlantic and is home to colorful fish and playful sea turtles, many of which are endangered.
Griffin and his team are studying how decreased tourism is impacting urban and agricultural sources of pollutants, such as nitrogen and phosphorus, to water quality off the coast of Belize.
In addition to on-the-ground data, the team is using Landsat images to note how the pandemic is affecting land use changes, which affects how many pollutants are produced and able to reach water bodies and ecosystems. Griffin is also using MODIS and VIIRS data to monitor water quality.