TL2MTLLN_7 is the Tropospheric Emission Spectrometer (TES)/Aura Level 2 Methanol Lite Nadir Version 7 data product. It consists of information for one molecular species for an entire Global Survey or Special Observation. TES was an instrument aboard NASA's Aura satellite and was launched from California on July 15, 2004. Data collection for TES is complete. The TES Lite products were intended to simplify TES data usage including data/model and data/data comparisons. This product can be used for science analysis as each data product is fully characterized. The TES Lite products were also meant to facilitate use of TES data by end users by (1) aggregating product results by month (no averaging is applied), (2) reducing data dimensionality to the retrieved pressure levels, which results in a minimal reduction of information but reduces data sizes by 1/3 to 1/10, (3) applying known corrections quantified through validation campaigns (4) combining data from ancillary files and multiple TES product files that are needed for science analysis (particularly for CH4 and HDO), and (5) removing fields that are not typically used. For example, the HDO product also includes the H2O product; it contains the recommended bias correction for HDO, results are mapped to 18 pressures, and the averaging kernel and error covariances are packed together from the H2O, HDO, and ancillary individual product files into full matrices for easier use by modelers and for science analysis. The products include the mapping matrix to relate the reduced-size retrieval vectors, covariances, and averaging kernels back to the TES forward model pressure grid to support cross-comparison between products and models. NH3 and CH4 contain Representative Tropospheric volume mixing ratio (RTVMR) fields (Payne et al. , 2009) that map the full profile to levels that are most representative of the atmosphere based on the altitude dependent sensitivity of the estimate.

TES Level 2 data contain retrieved species (or temperature) profiles at the observation targets and the estimated errors. The geolocation, quality, and other data (e.g., surface characteristics for nadir observations) were also provided. L2 modeled spectra were evaluated using radiative transfer modeling algorithms. The process, referred to as retrieval, compared observed spectra to the modeled spectra and iteratively updated the atmospheric parameters. L2 standard product files included information for one molecular species (or temperature) for an entire global survey or special observation run. A global survey consisted of a maximum of 16 consecutive orbits.

Nadir observations, which point directly to the surface of the Earth, are different from limb observations, which are pointed at various off-nadir angles into the atmosphere. Nadir and limb observations were added to separate L2 files, and a single ancillary file was composed of data that are common to both nadir and limb files. A Nadir sequence within the TES Global Survey was a fixed number of observations within an orbit for a Global Survey. Prior to April 24, 2005, it consisted of two low resolution scans over the same ground locations. After April 24, 2005, Global Survey data consisted of three low resolution scans. The Nadir standard product consists of four files, where each file is composed of the Global Survey Nadir observations from one of four focal planes for a single orbit, i.e. 72 orbit sequences. The Global Survey Nadir observations only used a single set of filter mix.

A Global Survey consisted of observations along 16 consecutive orbits at the start of a two day cycle, over which 3,200 retrievals were performed. Each observation was the input for retrievals of species Volume Mixing Ratios (VMRs), temperature profiles, surface temperature, and other data parameters with associated pressure levels, precision, total error, vertical resolution, total column density, and other diagnostic quantities. Each TES Level 2 standard product reporte