A long‐term data set of globally averaged thermospheric total mass density

We present a long‐term data set, available on the CEDAR Data System, of globally averaged thermospheric total mass density derived from the orbits of ∼5000 objects. The data cover the years 1967–2007 at heights from 200 to 600 km. The data have a temporal resolution of 3–6 days, a typical short‐term precision of ±2%, and a long‐term accuracy of 5–10%. We describe in detail the procedure used to generate the data set, provide an example of its scientific use, and discuss its limitations.