Quantifying the effect of sea breeze and winter storms on air-water CO2 exchange in a mega-city estuary

The atmospheric exchange of CO₂ in estuaries is enhanced by wind events, such as sea breeze, and winter storms. We are interested in the impacts of these wind events on air-water CO₂ flux in a mega-city estuary, due to the increasing numbers of storms, and the diurnal sea breeze throughout the summer in Jamaica Bay. Jamaica Bay, located within New York City, is an estuary formed of carbon-rich salt marshes. Here, we quantify and compare flux measurements in the estuary for the entire year of 2016. Measurements from a meteorological mast in Jamaica Bay and buoys around the New York Bay are used to identify sea breeze events, and the CO₂ flux was calculated using the eddy covariance method in conjunction with a flux footprint analysis. Here, we find values for the vertical turbulent flux of CO₂, F_CO2, during summer days with sea breeze (F_CO2 = -260 mmol m^-2 day^-1), without sea breeze (F_CO2 = 25 mmol m^-2 day^-1), and during the winter on stormy days (F_CO2 = 130 mmol m^-2 day^-1), and calm days (F_CO2 = 190 mmol m^-2 day^-1). Positive and negative values of F_CO2 correspond to the outgassing and uptake of CO₂ by the water, respectively. We find that Jamaica Bay is a net carbon source in the winter, and on sea breeze days in the summer, the estuary is a net carbon sink.