Seed Grant: Developing a geochemical database on the Bay of Bengal sediments for assessment of Indian river discharge


The monsoon climate represents one of the Earth's most dynamic and synoptic climatic interactions between atmosphere, oceans and continents. Approximately, one half of the humanity depends on the regular return of the monsoon for their livelihood in regions ranging from West Africa through Central to East Asia to Australia. The Indian Ocean monsoon (IOM) is the product of the pressure differences between the land-ocean sensible and the tropospheric latent heating. This pressure gradient sets the stage for the cyclonic summer-monsoon wind and evaporation from the tropical Indian Ocean supplying moisture which intensifies the monsoon. With the threat of increase in greenhouse gases and the ensuing global warming in this century, most of the climate models predict that the future IOM system may turn into early Holocene climate. At present, there are ~15,000 glaciers in the southern margin of the Himalayas hosting ~12,000 km3 of freshwaters. If the IPCC (2007) predictions of the global temperature rise become correct, then the availability of the freshwater resulting from melting of these glaciers and monsoonal rainfall to the agrarian community becomes a serious concern for their livelihood.

In this CWC funded Seed grant project, we wish to provide a geochemical database about the Indian monsoon intensity from the lower reaches of the Ganges-Brahmaputra-Meghna River delta to address the following questions:

  1. What are the changes in the Ganges-Brahmaputra-Meghna freshwater outflow fluxes as a result of the warming evident from the receding glaciers in the Himalayas?
  2. Were the early Holocene Ganges-Brahmaputra-Meghna rivers discharge fluxes similar to the recent outflow?
  3. Are they consistent with the Mount Kilimanjaro or other regional high-resolution hydrological variability records?
  4. Are the carbon fluxes increased as a result of increase in the deforestation and hence erosion in the Himalayan foothills?

In this study, we will address these questions by making measurements from the sediment and water samples from the Ganges-Brahmaputra-Meghna rivers basins and the Bay of Bengal. Our preliminary data generated from the CWC Seed Grant will be used to demonstrate the "proof of concept" which will be utilized to seek funds from federal and other funding agencies.