This map shows the presence of absorbing aerosols in dekadal (10-day) averages.
Analysis is based on an aerosol optical thickness index derived from the Multi-angle imaging SpectroRadiometer (MISR) instrument aboard NASA’s Terra satellite. High positive values indicate the presence of absorbing aerosols with a high optical thickness 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.
Additional aerosol analysis can be viewed on the Ozone Monitoring Instrument (OMI) 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
The map displays dekadal (10-day) averages of the MISR aerosol optical thickness index. Data is available from April 2000-April 2009. The dekadal average is only calculated when 90% of the daily values in a dekad are available.
Dekadal-average NASA Multi-angle Imaging SpectroRadiometer (MISR) aerosol optical thickness on a 0.25 x 0.25 deg. lat/lon grid. The dekadal average is calculated if at least 10% of the daily values in a dekad are non-missing.
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 MISR aerosols interface consists of a clickable map that allows users to generate customized time series graphs in different contextual perspectives.
When a desired location is clicked, a time series graph will provide aerosol analysis in a seasonal perspective from JAN 2000 until JAN 2009
By placing the current aerosol index in a seasonal perspective, patterns can be identified and useful early warning information can be developed for epidemic prone regions.