GlobAEROSOL: a long term global aerosol dataset from European satellite observations

GlobAEROSOL is an ESA-DUE project with the objective of delivering a long term EO dataset on aerosol data, with global coverage, for atmospheric research, air quality monitoring, and the formulation of policies on local and transboundary pollution.

Aerosols are a fundamental component of the Earth's atmospheric chemistry and radiative balance. Their importance in atmospheric radiative transfer means that the lack of accurate information on their distribution is a major limitation for weather forecasting. At the same time, aerosol distribution is also essential in the study of the Earth's climate and biogeochemical cycles, for climate change assessment, and for the atmospheric correction of satellite remote sensing data.

Particulate matter is also of major concern for public health. Although much of the anthropogenic component arises in industrial regions, it is often advected across national boundaries and affects remote and otherwise pristine environments. Information on the concentrations of particulates, the emission sources, transport and sinks are required by public agencies responsible for monitoring the environmental hazards to human health, and in the formulation of policies on local and transboundary pollution.

The GlobAEROSOL products consist of aerosol properties determined from measurements made by four different satellite radiometers: ATSR-2, from ERS-2; AATSR and MERIS, from ENVISAT; and SEVIRI, from MSG. The dataset spans the full operational lifetime of these instruments, up until the end of 2007, and thus provides an almost unbroken global coverage for the period ranging from 1995 to 2007.

Daily products -with a spatial resolution of 10 km- are provided for each individual instrument, comprising the aerosol optical thickness at 550 and 870 nm, the Ångström exponent, the retrieved aerosol effective radius, and an indication of the estimated aerosol speciation, among others. In addition, multi-sensor data is also available in the form of merged products, where retrievals from AATSR, MERIS and SEVIRI are combined in a single unit; along with monthly statistics with a reduced 1º latitude-longitude resolution.

As of October 2009, the full dataset is publicly available for download from the project website. Details on the project outcomes, the algorithms and analysis involved, as well as validation and intercomparison results and conclusions, are elaborated in the present paper.