The Global Ozone Monitoring Experiment–2 (GOME-2) is an optical spectrometer, fed by a scan mirror which enables across-track scanning in nadir, as well as sideways viewing for polar coverage and instrument characterisation measurements using the Moon (Figure 1). GOME-2 senses the Earth’s backscattered radiance and extraterrestrial solar irradiance, in the ultraviolet and visible part of the spectrum (240-790 nm), at a high spectral resolution, between 0.2–0.4 nm. 4096 spectral points from four detector channels are transferred per individual GOME-2 measurement (Figure 2).

The footprint size is 80 x 40 km for main channel data. The instrument also measures the state of linear polarisation of the backscattered earthshine radiances in two perpendicular directions. The polarisation data is down-linked in 15 spectral bands covering the region from 312 to 800 nm for both polarisation directions with a footprint of 10 x 40 km. The recorded spectra are used to derive a detailed picture of the total atmospheric content of ozone and the vertical ozone profile in the atmosphere. They also provide accurate information on the total column amount of nitrogen dioxide, sulphur dioxide, water vapour, oxygen / oxygen dimmer, bromine oxide and other trace gases, as well as aerosols (Figure 2). Figure 2: GOME-2 transmittance as derived from the GOME-2 level 1b radiance product.(Click to enlarge) Selected spectral regions, with absorption signatures used for various trace gas products, as derived from GOME-2 level-1b radiances, are shown.

GOME Summary Budgets

The GOME-2 instrument is developed by Galileo Avionica (now SELEX Galileo) in Florence, Italy, under a joint contract from EUMETSAT and ESA.

For a more detailed description, see the , or the GOME-2 Instrument Factsheet (PDF, 433 KB)

Instrument performance, product quality monitoring and further information regarding GOME-2 are provided on the page, and in the .