Earth, Atmosphere & Environment Sciences
Title : | Role of mesoscale variations over biogeochemical variability of the Indian coastal seas in the changing climate |
Area of research : | Earth, Atmosphere & Environment Sciences |
Focus area : | Oceanography, Biogeochemistry |
Principal Investigator : | Dr. Tanuja Nigam, CSIR- National Institute Of Oceanography, Goa |
Timeline Start Year : | 2024 |
Timeline End Year : | 2026 |
Contact info : | tanujanigam88@gmail.com |
Details
Executive Summary : | Mesoscale features are basically generated due to the frontal activity, instability (barotropic & baroclinic) of the mean flow in the oceans (Platov & Golubeva, 2020; Lèvy et al. 2012). Several mesoscale eddies are generated in the order of 10 to 100 km due to baroclinic and barotropic instabilities of the boundary currents shear. The energy from these instabilities of the ocean is proportional to the horizontal & vertical shear of zonal current in the ocean (Imakan et al. 2013). Baroclinic instability also generates in a static stable water column which can be better estimated by measuring changing temperature, salinity and resultant density stratification. The warming rate in the Indian Ocean is higher than any other ocean hence, the temperature, salinity, stratification and winds are subjected to be affected due to enhanced climatic thermal stress (Roxy et al. 2020). This implies that in changing climate, there is a strong possibility to experience significant changes on the generation and dissipation of these ocean instabilities and thereby, mesoscale eddies formation & related impacts to the upper ocean. Eddies can largely impact ocean stirring and mixing and causing the biogeochemical variations thereby changing phytoplankton distribution and pelagic ecosystems. The cyclonic eddies are generally capable of supplying the required amount of nutrients from subsurface to the euphotic depth to support the primary productivity in the ocean. Therefore, it is crucial to understand these interactions. The mixed layer evolution and dynamics is another crucial factor which influences marine productivity by changing the nutrients to the euphotic zone and also affected by mesoscale processes. It is established that eddies are responsible for the 90% of total kinetic energy of the global ocean and can be generated in all the ocean (Wunsch and Ferrari, 2004). One of the prominent feature of mesoscale oceanic processes are eddies which are the transporter of heat, salt, nutrient and other mass fluxes in the ocean. Zhao et al. 2021 has established that eddy-trapped or induced chlorophyll is found to be about half of the total chlorophyll in the ocean. The surface and subsurface structure of mesoscale eddies are affected through the wind, ocean water column temperature and salinity. These met-ocean parameters are significantly impacted by the natural climate variability modes and the anthropogenic activities in the climate projections. Still there is a lack of understanding regarding the impact of these met-ocean parameters variability on the mesoscale variability under changing climate in the Indian Ocean. This proposal aims at exploring interconnection & inter-response of climate change of mesoscale eddies variability and biogeochemistry of Indian coastal seas, Arabian Sea & Bay of Bengal with the below given objectives. |
Total Budget (INR): | 15,73,953 |
Organizations involved