It is a well known fact that atmospheric CO2 acts as Earth’s thermostat. It is also well known that rising CO2 levels in atmosphere have accelerated Earth’s current long-term warming trend. We also know that nearly half of all human-caused emissions are absorbed by the land and ocean — the current understanding is that about 50% of emissions remain in the atmosphere, about 25% are absorbed by vegetation on the land, and about 25% are absorbed by the ocean. However, what we don’t know are answers to some critical questions like which ecosystems, especially on land, are absorbing what amounts of CO2. Or how much CO2 stays in the atmosphere and how long it stays there? Or perhaps most significantly, as emissions keep rising, will the land and the ocean continue this rate of absorption, or reach a point of saturation – questions all important to track global warming and determine Earth’s future. Now, a NASA visualization of CO2 in air could get answers to all those questions.
Ground-based sensors have been used for decades to track the rising concentration of heat-trapping CO2. The new NASA supercomputer project builds on the agency’s satellite measurements of CO2 and combines the data with a sophisticated Earth system model to provide one of the most realistic views yet of how this critical greenhouse gas moves through the atmosphere.
What does the visualization reveal?
The high-resolution visualization in 3D — of data over the time period from September 2014 to September 2015 — reveals the patterns in which CO2 in the atmosphere increases, decreases and moves around Earth. This is expected to go a long way in our understanding of the processes that control the “carbon flux” which will ultimately determine Earth’s future climate. Carbon flux is the exchange of CO2 between the atmosphere, land and ocean.
“The new dataset is a step toward answering those questions,” explained Lesley Ott, a carbon cycle scientist at NASA Goddard and a member of the OCO-2 science team.
The visualization highlights information that has not been seen before in such clarity and detail — the rise and fall of CO2 in the Northern Hemisphere throughout a year; the influence of continents, mountain ranges and ocean currents on weather patterns and therefore carbon dioxide movement; and the regional influence of highly active photosynthesis in places like the US Corn Belt.
The Global Modeling and Assimilation Office (GMAO) at NASA‘s Goddard Space Flight Center generated the visualization by using data from the agency’s Orbiting Carbon Observatory-2 (OCO-2) satellite. The assimilation was done using a model called the Goddard Earth Observing System Model-Version 5 (GEOS-5), which was run by the Discover supercomputer cluster at Goddard’s NASA Center for Climate Simulation.
“The level of detail included in the dataset gives us a lot of optimism that our models and observations are beginning to give a coherent view of the carbon cycle,” says GMAO chief Steven Pawson. She believes one future step will be to integrate a more complex biology module into the model to better answer the questions of CO2 absorption and release by forests and other land ecosystems. “We can’t measure the flux directly at high resolution across the entire globe. We are trying to build the tools needed to provide an accurate picture of what’s happening in the atmosphere and translate that to an accurate picture of what’s going on with the flux. There’s still a long way to go, but this is a really important and necessary step in that chain of discoveries about carbon dioxide.”
READ: Why NASA is vital for battling climate change
What does OCO-2 satellite do?
Launched in 2014, OCO-2 is NASA‘s first satellite designed specifically to measure atmospheric carbon dioxide at regional scales. It has been giving almost 100,000 CO2 estimates over the globe each day.
OCO-2 is a replacement of the Orbiting Carbon Observatory which was lost in a launch failure in 2009 . The goal is to improve understanding of the carbon cycle on earth and the processes that regulate atmospheric concentration of carbon dioxide for better prediction of increase in carbon dioxide and its impact on Earth’s climate.
The GMAO had previously included carbon dioxide in its GEOS Earth system model, which is used for all manner of atmospheric studies. This new product builds on that work by using the technique of data assimilation to combine the OCO-2 observations with the model. “Data assimilation is the process of blending model simulations with real-world measurements, with the precision, resolution and coverage needed to reflect our best understanding of the exchange of carbon dioxide between the surface and atmosphere,” explained Brad Weir, a researcher based in the GMAO.