Assessment of cyclicity of weather

Bivariate cycles, such as in rainfall and temperature, can have widely different impacts on vegetation and animals than independent cycles in both components. UHOH will use existing climate data to build models to test for evidence of and quantify bivariate seasonal oscillations in weather components in the Greater Serengeti-Mara Ecosystem. Testing for presence and significance of bivariate cycles and quantifying quasi-periodic bivariate annual and seasonal rainfall, temperature and NDVI oscillations will be based on squared coherence and bivariate structural equation models (Diggle 1990; Harvey 1990). Climate change and land use change may also lead to progressive shifts in seasonal weather characteristics. UHOH will use existing climate data to build models for establishing if seasonality in rainfall, temperature and NDVI is progressively changing (evolving) over time in the Greater Serengeti-Mara Ecosystem.using complex demodulation analysis and structural time-series models.