Mapping Diseases

  • Released Friday, April 13th, 2012
  • Updated Wednesday, May 3rd, 2023 at 1:53PM

The print-resolution still images were created for the February 2012 issue of The Scientist (print and online). In an article in the same issue, NASA scientist Assaf Anyamba explains how he can predict diseases with remote-sensing data.

The data used are:

1. NDVI is an index that quantifies the photosynthetic capacity of vegetation. It is derived from visible and near-infrared reflectance measurements made by Advanced Very High Resolution Radiometer (AVHRR) sensors onboard NOAA's polar orbiting satellites (in this case NOAA-17). Taken as time series measurements, NDVI indicates the response of vegetation to seasonal and interannual variations in climate.

2. SST data are a blend of direct observations from ships, buoys, satellite imagery also from National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) instruments, and SSTs simulated by sea-ice cover. The monthly optimum interpolated fields were derived by a linear interpolation of the weekly fields to daily fields, and then averaging daily values over a month.

All anomaly fields (as shown here) are derived by subtracting the monthly values from the respective long-term monthly means.

This map shows combined anomalies in Sea-Surface Temperatures(SST)(oceans) and Normalized Difference Vegetation Index (NDVI) (land), observed globally for January 2007. The unusually high Sea Surface Temperatures (red) sustained in the western equatorial Indian Ocean and the central and eastern equatorial Pacific Ocean since the fall of 2006 caused an anomalous growth in vegetation (green-purple), in Eastern Africa due to persistent and heavy rainfall. Above normal rainfall combined with growth in vegetation created ideal ecological conditions for the emergence of mosquitoes that spread Rift Valley fever.

This map shows combined anomalies in Sea-Surface Temperatures(SST)(oceans) and Normalized Difference Vegetation Index (NDVI) (land), observed globally for January 2007. The unusually high Sea Surface Temperatures (red) sustained in the western equatorial Indian Ocean and the central and eastern equatorial Pacific Ocean since the fall of 2006 caused an anomalous growth in vegetation (green-purple), in Eastern Africa due to persistent and heavy rainfall. Above normal rainfall combined with growth in vegetation created ideal ecological conditions for the emergence of mosquitoes that spread Rift Valley fever.

Sea Surface Temperature (SST) Anomaly color scale.

Sea Surface Temperature (SST) Anomaly color scale.

Normalized Difference Vegetation Index (NDVI) Anomaly percent color scale.

Normalized Difference Vegetation Index (NDVI) Anomaly percent color scale.



Credits

Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio


Papers used in this visualization


Datasets used in this visualization

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