DATA ACCESS

The Stratospheric Aerosol and Gas Experiment III (SAGE III) obtains profile measurements of aerosol extinction, ozone, water vapor, nitrogen dioxide, nitrogen trioxide, chlorine dioxide, clouds, temperature and pressure in the mesosphere, stratosphere, and upper troposphere with a vertical resolution of 0.5 - 1 km resolution.

SAGE III Data Set Version 3 is publicly available at NASA Langley's Atmospheric Sciences Data Center. This data set includes improvements to its solar ozone, nitrogen dioxide, and aerosol extinction products. It also includes the release of a cloud presence identifier and lunar data products. These data will cover the period starting in 27-February-2002.

SAGE III DATA USER'S GUIDE AND DATA READERS

Download the SAGE III Data User's Guide and data readers »

PUBLIC DATA ACCESS

Officially released data sets to the public are available from the NASA Langley's Atmospheric Sciences Data Center ».

FILE NAMING CONVENTION

Following is a list of products and the file naming convention for each product that shall be generated by SAGE III SCF processing:

LEVEL 1B SOLAR TRANSMISSION PRODUCT

The Level 1B Transmission product contains the SAGE III atmospheric slant path transmission profiles at 85 spectral channels. The profiles are skewed vertically and extend from sea level to an altitude of 100 km in 0.5 km intervals. These data have been geolocated and normalized against exoatmospheric solar measurements to produce slant path transmission profiles. The Level 1B product is only available for solar measurements.

LEVEL 2 SOLAR SPECIES PRODUCT

The Level 2 Solar Species products are produced from the Level 1B Transmission profiles. The content of the Level 2 Solar Species organized by species, each including information on its relative uncertainty. Species are reported in profiles on a geometric altitude coordinate system with a vertical resolution of 0.5 km.

LEVEL 2 CLOUD PRODUCT (FROM SOLAR DATA)

The SAGE III instrument detects subvisible and opaque clouds by using measurements of aerosol extinction and their uncertainties at wavelengths of 525, 1020, and 1550 nm. The basic product consists of 3 vertical profiles extending from 0 to 30 km that contain information on the presence of clouds at 0.5 km intervals. Unlike all other Level 2 products, a granule of this product contains a collection of cloud data for one calendar month.

LEVEL 2 LUNAR SPECIES PRODUCT

The retrieval of constituent profiles from irradiance measurements acquired during lunar occultation events is a new capability for the SAGE III experiment. These retrievals are more complex than those employed for solar events because they account for the spatial and spectral non-uniformity of the surface albedo of the moon and the much lower measurement signal. One important difference between the solar and lunar retrieval techniques is the absence of a Level 1B slant path transmission profile product for lunar occultation retrievals. This is a consequence of not being able to determine limbdarkening curves with sufficient accuracy to calibrate each SAGE III lunar occultation event.

A single scan vertical resolution of the lunar Level 2 products is 1 km. The chemical species concentration data from multiple scans are bin-averaged and reported on a geometric coordinate system with a vertical resolution of 0.5 km to maintain grid spacing compatibility with the solar Level 2 products.