4.2.4 Impact of Seasonal Variability on Regional Contribution to Radiative Forcing
Our observations show that the nBUS is a year-round source of GHG to the atmosphere, although the sea-air fluxes peak in winter. In order to assess the nBUS share to radiative forcing, we analyzed the seasonal variability of the weighted contribution of GHG using the global warming potential (GWP) for time horizons of 20 (GWP20) and 100 (GWP100) years revealed that during winter, CO2 emissions dominated at a rate of 70 – 73%, followed by N2O and CH4. Conversely, the significance of CO2 emissions notably decreased during summer (23 – 30%), with a comparable contribution from N2O (38 – 51%) and CH4 (17 – 38%) emissions (Figure 9 and Resplandy et al., 2024).