The effect of storm events on carbon cycling for the Nova Scotia Shelf region

Abstract

Seasonal changes in carbon cycling over the years have become better understood on the Scotian Shelf, however little is resolved in short term variation. Focusing on the storm event, Hurricane Arthur, July 5th 2014 there is a drop in the partial pressure of CO2. With the shelf having carbon rich deep water, a reduction of the partial pressure of CO2 due to mixing went against current understanding. Slightly above the thermocline there is a sustained population of phytoplankton, causing water in the surrounding area to be lower in dissolved inorganic carbon. When wind mixing from storms occurs, low dissolved inorganic carbon water and phytoplankton from the cold intermediate layer move to the surface. At the surface phytoplankton begin to grow more rapidly due to available nutrients and increased light. This growth and low DIC water then reduces the partial pressure of CO2 for a short period of time until wind speeds slow down reducing mixing of the water column.