资源环境科技发展态势分析平台

The effect of aerosol emissions from an active shipping lane in the Indian Ocean is simulated using an idealized framework in a cloud-resolving model. Increased aerosol concentrations over the modeled shipping lane lead to increased cloud droplet number, cloud liquid mass, ice hydrometeor mass, and simulated radar reflectivity. The invigoration of deep convection induces mesoscale uplift and increased precipitation over the shipping lane. A predicted increase in the prevalence of both strong updrafts and radar echoes aloft is suggestive of enhanced lightning activity over the shipping lane, as observed in a recent study. Cloud radiative effects, both shortwave and longwave, are intensified over the shipping lane, but the change in the net radiative flux at top of atmosphere is not significantly different from zero.

Plain Language Summary Clouds are made up in part of droplets that form on small, airborne particles that come from both natural and manmade sources. Rain tends to form more slowly in clouds with more numerous and smaller cloud droplets, so that clouds in polluted regions (with higher particle concentrations) may be slower to rain than similar ones in cleaner regions. Past research has suggested that thunderstorms forming over polluted regions may grow more intense than similar storms that form in cleaner regions, because less cloud water is removed by rain and more of it freezes higher up in the storm. This freezing releases heat that further intensifies the storm. Recently, lightning was found to occur more often above shipping lanes in South and Southeast Asia than away from the shipping lane. We have simulated the approximate effect of ship-derived pollution on the storms and found that storms are strengthened over the shipping lane. Increases in rainfall and cloud cover are modest. However, stronger changes occur higher up in the storms with increases in the occurrence of large ice particles that are also seen by a satellite over the shipping lane in the Indian Ocean.