First, Researchers have discovered short-term, regional variations in global atmospheric carbon dioxide (CO2) due to emissions from human activities.
Using a combination of NASA satellites and atmospheric models, scientists have made the first detection of changes in human CO2 emissions. New study uses data from NASA’s Orbital Carbon Observatory-2 (OCO-2) to measure reduced CO2 emissions during the COVID-19 pandemic from space. With daily and Monthly Data products are now available to the public, which opens up new possibilities for tracking the overall effects of human activities on CO2 concentrations in near real time.
Previous studies investigated the impact of lockdowns early in the pandemic and found that global CO2 levels fell slightly in 2020. However, by combining OCO-2’s high-resolution data with analytical tools data and models from NASA Goddard . Earth Observation System (GEOS), the team was able to narrow down the monthly changes to human activity and natural causes to a regional scale. This confirms previous estimates based on economic data and human activity.
The team’s measurements show that in the Northern Hemisphere, the growth in anthropogenic CO2 concentrations decreased from February to May 2020 and increased again during the summer, in line with the reductions in emissions. globally from 3% to 13% during the year.
The results represent a giant leap forward for researchers studying the effects of climate change in the region and monitoring the results of mitigation strategies, the team said. This method enables changes in atmospheric CO2 to be detected just a month or two after they occur, providing quick, actionable information on how humans evolve and natural emissions. .
NASA Tracks Fingerprints in the Atmosphere of COVID-19
Visible subtle changes in Earth’s atmosphere
Carbon dioxide (CO2) is a greenhouse gas present in the atmosphere and its concentration varies due to natural processes such as plant respiration, exchange with the world’s oceans, and human activities such as fuel combustion. fossils and deforestation. Since the Industrial Revolution, the concentration of CO2 in the atmosphere has increased by nearly 49%, pass 400 parts per million for the first time in human history in 2013.
As governments ask people to stay home early in the COVID-19 pandemic, fewer cars on the road means a sharp drop in greenhouse gases and pollutants released into the atmosphere. But with CO2, a “strong drop” needs to be put in the context, Lesley Otta research meteorologist at NASA’s Office of Global Modeling and Assimilation at the Goddard Space Flight Center in Greenbelt, Maryland. This gas can remain in the atmosphere for up to a century after it is released, which is why short-term changes can be lost in the overall global carbon cycle – a chain of absorption and release involves natural as well as human processes. The outages in early 2020 are a small part of the total CO2 picture for the year.
“Early in 2020 we saw the fires in Australia release CO2, we saw the crops in India absorb more, and we saw all these different effects mixed with,” says Ott. together. “The challenge is trying to debug that and understand what all the different components are.”
Until recently, measuring these types of changes was not possible with satellite technology. NASA’s OCO-2 satellite features a high-precision spectrometer designed to pick up even smaller CO2 fluctuations, and combined with a comprehensive GEOS Earth system model, is well suited for detecting showing pandemic-related changes.
“OCO-2 is not designed to monitor emissions, but it is designed to see signals that are even smaller than what we have seen with COVID,” said the lead author. Brad Weir, a research scientist at Goddard and Morgan State Universities. Weir explains that one of the research goals of the OCO-2 mission is to track changes in human emissions in response to climate policies, which are expected to produce small changes. , gradually returning to CO2. “We hope that this measurement system will be able to detect a disruption as large as COVID.”
The team compared measured changes in atmospheric CO2 with independent estimates of emissions changes due to the lockdown. In addition to confirming other estimates, the agreement between emission models and atmospheric CO2 measurements provides strong evidence that the reductions are due to human activities.
GEOS has contributed important information on wind patterns and other natural weather variations that affect CO2 emissions and transport. “This research is really putting everything together to attack an extremely difficult problem,” says Ott.
A closer look at greenhouse gases
The team’s results showed an increase in CO2 concentrations decreased in the Northern Hemisphere from February to May 2020 (for a global emission reduction of 3% and 13%, respectively), agreeing with the models. computer simulations of how the restrictions operate and natural influences will affect the atmosphere.
The signal isn’t as clear-cut in the Southern Hemisphere, thanks to another record-breaking climate anomaly: Indian Ocean Dipole, or IOD. The IOD is a cyclical pattern of colder-than-normal oceans in Southeast Asia and warmer-than-normal oceans in the eastern Indian Ocean (“positive” phase) or vice versa (“negative” phase). At the end of 2019 and the beginning of 2020, the IOD experienced a active periodyielded a bountiful harvest in sub-Saharan Africa and contributed to record-setting Fire season in Australia. Both events strongly affect the carbon cycle and make detection of the COVID key signal difficult – but also demonstrate the potential of GEOS/OCO-2 in variable monitoring, the team says future natural CO2 dynamics.
GEOS/OCO-2 data powers one of the indicators in COVID-19 Earth Observation Dashboard, a partnership between NASA, the European Space Agency and the Japan Aerospace Exploration Agency. A global dashboard that aggregates data and metrics to track how lockdowns, significant reductions in shipping, and other COVID-related actions are impacting our ecosystem. Earth.
The GEOS-OCO-2 assimilation product is available for free download, helping researchers and students who want to learn more.
“Scientists can go into this dashboard and say, ‘I see something interesting in the CO2 signal; Ott said. “There’s all the stuff we haven’t explored in these datasets and I think it helps people explore in a new way.”
In the future, the new assimilation and analysis method could also be used to help monitor the results of climate mitigation programs and policies, particularly at the community or regional level, the team says. area.
“Having the ability to monitor how our climate is changing, knowing this technology is ready, is something we are really proud of,” says Ott.
By Jessica Merzdorf Evans
NASA’s Goddard Space Flight Center, Greenbelt, MD
Last Updated: March 31, 2022
Editor: Jessica Merzdorf
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