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).