Abstract Sulfate burden over the North Atlantic Ocean (NATL) exhibits strong seasonality despite no seasonality in anthropogenic sulfur dioxide (SO2) emissions. However, the seasonality of sulfate aerosols over NATL has decreased since 1970, likely due to a reduction in the United States (US) SO2 emissions following the Clean Air Act of 1970. We performed atmospheric chemistry and transport simulations to assess the impact of changing US SO2 emissions between 1970 and 2010 on NATL sulfate burden and radiative forcing. United States SO2 emission reductions weakened the seasonality in NATL sulfate burden by ā¼17%, primarily due to a decrease in chemical production and transport in summer. These emission reductions caused a summertime radiative forcing (ā¼2 W mā2) twice as large as the wintertime forcing. Our findings highlight the complex, seasonādependent responses of sulfate burden and radiative effects to regional emission changes.
Observations from the Little Bunker
Last updated: October 16, 2025 02:57 AM
Atmospheric COā
424.4 ppm
+18.2
ppm/year
Atmospheric CHā
1933.54 ppb
+12.29
ppb/year
Global Temperature
+1.48 Ā°C
Peak: +1.73Ā°C
World Population
8.1 billion
+67
million/year