TES focuses on the troposphere, the layer of atmosphere that stretches from the ground to the altitude at which airplanes fly. With very high spectral resolution, TES can distinguish concentrations of gases at different altitudes, a key factor in understanding their behavior and impact. It's the first orbiting instrument able to do this with ozone, a very important chemical with regard to both global warming and air pollution.
The primary location for obtaining TES data is NASA's Warehouse Inventory Search Tool (WIST). The TES Data Sets page at NASA Langley Research Center (LaRC ASDC) provides access to software read tools, a Data Pool, and supporting documentation.