Earth 

Mapping Diseases

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.

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.


Visualization Credits

Helen-Nicole Kostis (USRA): Lead Animator
Greg Shirah (NASA/GSFC): Animator
Assaf Anyamba (USRA): Scientist
Jennifer Small (SSAI): Scientist
Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio

Science Paper:
PLOS Neglected Tropical Disease (PLOS NTDs) Article: Climate Teleconnections and Recent Patterns of Human and Animal Disease Outbreaks

Short URL to share this page:
http://svs.gsfc.nasa.gov/goto?3905

Data Used:
NOAA/AVHRR/NDVI January 2007 Collection: 2003-2008
NOAA/AVHRR/Sea Surface Temperature January 2007 Collection: 1982-2008

Keywords:
SVS >> Earth Science
DLESE >> Environmental science
DLESE >> Human geography
GCMD >> Earth Science >> Human Dimensions >> Human Health >> Diseases/Epidemics
GCMD >> Location >> Africa
GCMD >> Location >> East Africa
NASA Science >> Earth

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0