AC SAF Logo

Near real-time IASI dust profile

Example images of IASI dust optical depth measurements at 10 µm

Description

The near real-time IASI dust profile product provides vertical profiles of desert dust aerosol number concentration retrieved from IASI observations, the integrated dust 10 µm AOD and the dust mean altitude, together with uncertainty assessment, averaging kernels, flags.

Type

Near real-time. Based on product requirements, the product files must be available to users within three hours after observation.

Theoretical basis

The retrieval of this product is based on optimal estimation, with the Levenberg Marquardt implementation, applied on the surface temperature and the profile of logarithm of the dust concentration. It uses IASI level 1d data (spectra in the principal component form) and IASI level 2 temperature and humidity profiles, together with some other ancillary data.

Processing

The MAPIR algorithm is a dedicated retrieval software for this product, using the RTTOV radiative transfer tool. It was developed at BIRA-IASB.

Units and spatial resolution

Dust concentration is given in particles/cm3, aerosol optical depth (without unit) at 10 µm (with conversion to 550 nm using the 1.78 factor as described in the documentation). The spatial resolution is the same as IASI observations (12 km diameter at nadir), as this is a level 2 product.

Validation

This product is under validation by AUTH, DWD and KMI. Validation is based on detailed comparisons with ground-based and satellite data. The climate version of the same product (expected to be highly similar but not exactly identical) has been validated and the more specific profile validation is under preparation for publication.

Dissemination

See NRT access information.

File format

This product is available in NetCDF format.

Algorithm version information

MAPIR v5.11

Documents