SEANA

Global shipping is undergoing significant changes. In January 2020 the maximum sulphur emission by ships in international waters will reduce from 3.5% to 0.5% by mass, as a result of new International Maritime Organisation (IMO) regulations. Superimposed on that, changes in Arctic sea ice are opening up new seaways enabling shorter sea passages between key markets. As a result, significant growth in shipping via the North West Passage is anticipated in the coming years.

Ships are major emitters of pollutant gases and particles that affect air quality and climate. A key challenge for assessing the climate impact is knowing the status of the natural/baseline aerosol system. There exists a short window of opportunity to define current atmospheric conditions, against which the impact of these changes must be determined.

SEANA is a NERC-funded project, led by Dr Zongbo Shi (U. Birmingham) that aims to define the baseline atmosphere and model potential future changes. Multiple atmospheric measurements will be made from multiple platforms, to understand the sources of natural aerosol particles in addition to detecting the present-day impact of shipping. Indeed, a key role for BAS is to carry out novel atmospheric measurements during a cruise to the west of the North West Passage. Together, these new observations will be used in conjunction with a global aerosol microphysics model to predict the future impact of shipping on air quality, clouds and radiative forcing under multiple sea-ice and shipping scenarios.

The transition to low-sulphur emissions in 2020 is an unprecedented opportunity to observe the impact of rapid emission reductions and constrain this response in atmospheric models. SEANA will provide unique observational data that will transform our model capacity to capture baseline Arctic and North Atlantic maritime aerosol and responses to emission changes, results of which will directly inform shipping policy at high-latitudes.