Archive for the ‘Climate’ Category

Large-scale vegetation-rainfall correlations in Africa

Weather and climatic variability affect vegetation on continental scales. Intuitively, healthy vegetation is greener. A quantitative index of “greenness” called Normalised Difference Vegetation Index (NDVI) was developed by NASA.В  The index takes values between 0 and 1. NDVI is related to the fraction of photosynthetically active radiation absorbed by the vegetation canopy. It is a [...]

May 12, 2010  Tags: , ,   Posted in: Climate, ecosystem model  No Comments

Visualizing the jet stream

Jet streams are narrow tubes of strong westerly winds which circle the earth at ≈ 10km elevation. These strong winds separate regions of cold and warm air. Surface weather at mid-latitudes is affected by the chaotic meanderings of jet streams.

The above wind speed maps are based on NCEP GFS analysis at 300mb pressure level (equivalent to [...]

January 14, 2010  Tags:   Posted in: Climate  No Comments