Research Projects

Recent studies indicate that climate change is posing a significant threat to humans and biodiversity (IPCC, 2021). The Indian Monsoon is an integral part of the global climate system (Katzenberger et al. 2021) and is characterized by a robust seasonal reversal of the prevailing surface winds and sharp contrast between rainy summer and arid winter (Wang et al. 2014). Indian summer monsoon (ISM) precipitation serves as the primary source of freshwater for the majority of the Indian subcontinent (Clemens et al. 2021) and plays a crucial role in India's agriculture and many other facets of life (Prassanna, 2014). Bay of Bengal (BoB) is one of the freshest oceanic basins and it receives over 3000 km3 of riverine freshwater per year (Subramanian, 1993). Around 80% of this volume results from ISM precipitation that originates in nearby continental areas, including discharge from Ganges-Brahmaputra-Meghna (GBM) river complex (Durand et al. 2011; Clemens et al. 2016). The variation in ISM additionally influences the biogeochemical cycling across South Asia and the Indian Ocean (Sein at al. 2022). The productivity in the upper layer of BoB is linked to the nutrient delivery to the upper oceans, which can be modulated by ocean-atmospheric processes associated with the ISM (Unger et al. 2003). The riverine flux, near-coastal eddy pumping, seasonal barrier-layer stratification, and upwelling are the key factors controlling the Bay of Bengal (BoB) productivity (Mukherjee et al. 2018). According to recent studies, the ODZ in the BoB has remarkably expanded for the past few decades in response to global warming which negatively impacts ocean productivity (Stramma et al. 2010). Recent research reported that the Bay of Bengal productivity collapsed during the intense early Holocene monsoon (EH) and the weakest Heinrich event (HE-1) due to upper ocean stratification (Thirumalai et al. 2022). However, the role of oxygen in the upper ocean of BoB during this interval has not yet been explored. In the last decades, limited study has been carried out on the reconstruction of ocean water oxygen previous deglaciations and Last Glacial Maximum (LGM) (Hoogakker. 2015, 2018; Anderson, 2019; Yamamoto et al. 2019; Eredem et al. 2020; Jacobel 2020; Lu et al. 2020; Lu et al 2021; Cliff et al. 2021; Lu et al. 2022). Most of the mentioned research has focused on major oxygen deficient zones (ODZs) of the world ocean including the eastern tropical Pacific Ocean, Atlantic Ocean, Peruvian and Portuguese Margin. Here, I propose to quantify the impact of global climate changes and ISM intensity oxygen cycles in the BoB, which is home to one of the world’s major ODZs. This will be the first study of its kind in the Bay of Bengal.