Join Earth, Energy and Environment for the first event in our weekly colloquium series for Academic Year 26/27. This week, Qinjian Jin will present "Reduced Lightning Activity over the Bay of Bengal ASsociated with Declining Shipping Emissions". Reduced Lightning Activity over the Bay of Bengal Associated with Declinin...
Join Earth, Energy and Environment for the first event in our weekly colloquium series for Academic Year 26/27. This week, Qinjian Jin will present "Reduced Lightning Activity over the Bay of Bengal ASsociated with Declining Shipping Emissions". Reduced Lightning Activity over the Bay of Bengal Associated with Declining Shipping Emissions Lightning plays a crucial role in the Earth’s biogeochemical cycle. Frequent lightning activity over the Bay of Bengal (BoB) has been attributed to shipping emissions through aerosol–cloud interactions in modeling studies but lacks observational confirmation. Here, we present observational evidence linking frequent lightning to the response of deep clouds to ship-emitted sulfate aerosols. These aerosols cause higher cloud tops in mid-to-high clouds, smaller cloud droplet sizes at the bases of low clouds, and increased ice water content with smaller ice particles in deep clouds along shipping lanes, resulting in more lightning strikes than in surrounding areas. The 2020 fuel regulation, which reduced SO₂ emissions by 66% over the BoB, led to lower cloud tops, reduced ice water content, larger cloud droplets, and consequently an 11% decline in lightning frequency during the period of 2020–2023 relative to its climatology. These results underscore the broader atmospheric impact of maritime policies, extending beyond local radiative effects to influence convective processes and natural hazards. Our colloquia are held on Fridays at 3:30 in Malott 2001. There is a pre-colloquium reception with receptions in Malott 3022 at 3:00. We hope to see you there!
