Study on the biogeochemistry of mud banks in southwest coast of India and its implications on climate change , Phase I Continuous Boi-geochemical monitoring
Implementing Organization
NIO, Kochi, Kerala
Principal Investigator
Dr. Gireesh Kumar T.R.
NIO Kochi, Kerala
CO-Principal Investigator
Anas Abdulaziz
Central Marine Fisheries Research Institute (CFMRI), Kochi, Kerala 682018
NIO
Project Overview
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)