Global Patterns of Carbon Dioxide Variability from Satellite Observations

Abstract

Advanced satellite technology has been providing unique observations of global carbon dioxide (CO2) concentrations. These observations have revealed important CO2 variability at different timescales and over regional and planetary scales. Satellite CO2 retrievals have revealed that stratospheric sudden warming and the Madden-Julian Oscillation can modulate atmospheric CO2 concentrations in the mid-troposphere. Atmospheric CO2 also demonstrates variability at interannual timescales. In the tropical region, the El Niño–Southern Oscillation and the Tropospheric Biennial Oscillation can change atmospheric CO2 concentrations. At high latitudes, mid-tropospheric CO2 concentrations can be influenced by the Northern Hemispheric annular mode. In addition to modulations by the large-scale circulations, sporadic events such as wildfires, volcanic eruptions, and droughts, which change CO2 surface emissions, can cause atmospheric CO2 concentrations to increase significantly. The natural variability of CO2 summarized in this review can help us better understand its sources and sinks and its redistribution by atmospheric motion. ▪ Global satellite CO2 data offer a unique opportunity to explore CO2 variability in different regions. ▪ Atmospheric CO2 concentration demonstrates variations at intraseasonal, seasonal, and interannual timescales. ▪ Both large-scale circulations and variations of surface emissions can modulate CO2 concentrations in the atmosphere.