Source: NASA/JPL AIRS Project, NASA/Goddard Space Flight Center Scientific Visualization Studio
Published: July 8, 2019

This visualization is a time-series of the global distribution and variation of the concentration of mid-tropospheric carbon dioxide observed by the Atmospheric Infrared Sounder (AIRS) on the NASA Aqua spacecraft. For comparison, it is overlain by a graph of the seasonal variation and interannual increase of carbon dioxide observed at the Mauna Loa, Hawaii observatory. The AIRS data show the average concentration (parts per million) over an altitude range of 3 km to 13 km, whereas the Mauna Loa data show the concentration at an altitude of 3.4 km and its annual increase at a rate of approximately 2 parts per million (ppm) per year.

The two most notable features of this visualization are the seasonal variation of CO2 and the trend of increase in its concentration from year to year. The global map clearly shows that the carbon dioxide in the northern hemisphere peaks in April-May and then drops to a minimum in September-October. Although the seasonal cycle is less pronounced in the southern hemisphere it is opposite to that in the northern hemisphere. This seasonal cycle is governed by the growth cycle of plants. The northern hemisphere has the majority of the land masses, and so the amplitude of the cycle is greater in that hemisphere. The overall color of the map shifts toward the red with advancing time due to the annual increase of carbon dioxide.

Although the mid-latitude jet streams are not visible in the map, we can see their influence upon the distribution of carbon dioxide around the globe. These rivers of air occur at an altitude of about 5 km and rapidly transport carbon dioxide around the globe at that altitude. In the northern hemisphere, the mid-latitude jet stream squirms like a released garden hose over the period of a few days due to the continental landmasses.

In the southern hemisphere the jet stream flow is more directly West to East, and during the period from July to October the carbon dioxide concentration is enhanced in a belt delineated by the jet stream and lofting of carbon dioxide into the free troposphere by the high Andes is visible in this period. The zonal flow of carbon dioxide around the globe at the latitude of South Africa, southern Australia and southern South America is readily apparent.

The eastward flow of carbon dioxide from Indonesia and the Celebes sea can be seen in the November to February time frame.