Research Projects

The study attempted the continuous measurement of key biogeochemical variables using an environmental data buoy equipped with temperature, salinity, dissolved oxygen, methane and carbon dioxide sensors and generated hourly data sets to understand the hydro- chemical variations in diurnal to seasonal scale. Based on the monthly time series measurements, this project delineated the pathways and fluxes of climate-relevant trace gases in the southeastern Arabian Sea. Seasonal upwelling and the associated incursion of hypoxic waters into the coastal zone are widely studied topics over different upwelling zones. However, its persistence or variations over short time scales are poorly addressed due to the difficulties in continuous data collection in a rough sea (> 3 m) and inclement weather. This project brought out a first report on hourly variations in the temperature, salinity and dissolved oxygen recorded by an environmental data buoy equipped with sensors deployed in the nearshore waters of Alappuzha (southeastern Arabian Sea) from April to August 2022. The results showed that despite an advance in the upwelling intensity, there is a significant variation in the oxygen concentration in the study domain on a diurnal scale. In general, the nearshore region was under hypoxia during morning hours (06:00 to 12:00 hours), which increased steadily to reach normoxic and supersaturated levels during the rest of the day (12:00 to 24:00 hours)

Ship-based coastal time-series observations generated our current understanding of coastal ocean biogeochemistry, and such discrete sampling strategies do not capture a large part of the biogeochemical variability. During the last two decades, technological advances have led to the development of physical and biogeochemical sensors and the real-time transmission of sensor-derived data to the shore laboratory. The environmental buoy high- resolution data sets of physical (temperature and salinity) and biogeochemical variables will generate high-resolution data sets for operational oceanography. The high-resolution data sets