Observations for


a) Dekadal (i.e., ~10-daily) aerosol index estimates for the selected region from 2005 to the present.

b) Same as (a) for the current year (thick black line), as indicated by the axis labels. Aerosol Index estimates from previous years are also shown (blue-1 yr from present; magenta- 2 yrs from present; grey-3 yrs from present).

OMI Aerosol Monitoring for Meningitis

This map shows the presence of aerosols in dekadal (10-day) averages.

Analysis is based on an Aerosol index derived from the Ozone Monitoring Instrument (OMI) aboard NASA’s Aura satellite. High positive values indicate the presence of absorbing aerosols such as desert dust, smoke and volcanic ash.

Studies have shown that destabilized mucous membranes in the pharynx allow for the meningitis bacteria to pass through the blood, thus increasing the probability of infection. The desert aerosols (dust) are used as a predictive indicator to meningitis epidemics as they tend to destabilize mucous membranes and lead to increased vulnerability of a population.

The aerosols included in the index may be of various types and detected at any height in the atmosphere, not necessarily at the surface.

Additional aerosol analysis can be viewed on the Multi-angle Imaging SpectroRadiometer (MISR) map page.

OMI indicates the presence of aerosols in the form of an index whereas MISR indicates the aerosol optical thickness (AOT) of existing aerosols.

Dataset Documentation

Dekadal aerosol index estimates on a 1.0° x 1.0° lat/lon grid
Data Source
NASA GSFC OMI Aerosol data from NASA GSFC

This map displays dekadal (10-day) averages of the OMI aerosol index. The dekadal average is calculated if at least two-thirds of the daily values in a dekad are non-missing.

The data sets were computed using only positive values (i.e. absorbing aerosol indices) of the aerosol index for each dekad.


Access the dataset used to create this map.


Contact help@iri.columbia.edu with any technical questions or problems with this Map Room, for example, the forecasts not displaying or updating properly.


The OMI aerosols interface consists of a clickable map that allows users to generate customized time series graphs in different contextual perspectives. When a desired African location is clicked, 2 time series graphs will provide contextual analysis in the following perspectives:

a. Seasonal perspective - A single time series from 2005 until present.

b. Historical perspective - The data of the past year in comparison to the 3 most recent years.

The interface also allows users to select different scales of spatial averaging.

By placing the current aerosol index in recent historical and seasonal perspective, comparisons can be made to past outbreaks and useful early warning information can be developed for epidemic prone regions.