Close Window

Analysis of the relationship between climate and NDVI variability at global scales

Fanwei Zeng, SSAI, NASA GSFC, fanwei.zeng@nasa.gov (Presenter)
Jim Collatz, NASA GSFC, jim.collatz@nasa.gov
Jorge Pinzon, SSAI, NASA GSFC, jorge.e.pinzon@nasa.gov
Alvaro Ivanoff, ADNET, NASA GSFC, alvaro.ivanoff-1@nasa.gov

AVHRR (Advanced Very High Resolution Radiometer) NDVI (Normalized Difference Vegetation Index) is the longest spatially complete global record of variability in absorption of solar radiation by vegetation. AVHRR data have many limitations that are addressed in more recent and advanced sensor such as MODIS (MODerate resolution Imaging Spectroradiometer). We analyzed a new AVHRR product version, GIMMSg2 which spans

1982 through the present. The high, statistically significant correlations between GIMMS and MODIS NDVI anomalies during the period of overlap (2003-2010) for most of the vegetated surface of the globe demonstrate that GIMMS NDVI is a reliable measure of vegetation cover. Here we analyze the correlation between GIMMS NDVI anomalies and current and preceding precipitation and temperature anomalies. Not unexpectedly we find the highest correlations between precipitation and NDVI in temperate to subtropical

regions where precipitation amounts are limiting vegetation growth in combination with low percentages of evergreen vegetation. Strongest correlations are observed for 0.5 – 1.5 months preceding precipitation. Temperature-NDVI anomaly correlations tend to be highest at higher latitudes. Strongest correlations are observed for temperature in current month. Generally areas with positive precipitation-NDVI correlations coincide with areas with negative temperature-NDVI correlations. MODIS NDVI shows similar spatial

distributions of correlations with temperature and precipitation, and regions where GIMMS and MODIS NDVI show low correlations between each other also tend to show low correlations between either NDVI product and climate anomalies. This occurs for instance in the tropical forests where cloudiness and water vapor interfere with measurements from both instruments. Finally, we present evidence of recent climate driven NDVI variability.

Presentation: 2011_Poster_Zeng_101_2.pdf (1311k)

Presentation Type:  Poster

Session:  Other   (Mon 4:00 PM)

Associated Project(s): 

  • Collatz, Jim: Impacts of Disturbance History and Climate on Carbon Fluxes from North American Forests: Application of Satellite, Inventory, and Climate Data to Inform Biogeochemical Modeling ...details

Poster Location ID: 101

 


Close Window