Simple Plumes

Simple Plumes (SP) is a framework to efficiently incorporate the latest observational data into a new representation of aerosol emissions for use in global climate models. The approach is offline (computationally efficient), allowing a flexible framework to easily test many sets of input parameters. SP is constructed by combining global aerosol optical depth observations with the latest optical property estimates and adjustable spatiotemporal scaling to create a series of plumes that approximate global aerosol optical depth over time.

To modellers/data providers: The SP representation can be adapted for different aerosol types (e.g., anthropogenic, mineral dust, and sea salt). It can flexibly incorporate different data sources (e.g., reanalysis products, satellite retrievals or measurements of optical properties). Additionally, the temporal scaling enables studies of historical and future scenarios. SP can be used to easily test the radiative forcing sensitivity to aerosol emissions. 

• Anthropogenic aerosols are represented using predefined plume patterns linked to major industrial and biomass burning regions.
• Temporal evolution is driven by scaling plume structures with SO2 and NH3 emissions, producing time-evolving global aerosol fields.
• The SPv2.1 dataset provides aerosol optical properties and cloud droplet number concentration for 1850 to 2023, and is being extended to future scenarios (to 2100) based on ScenarioMIP pathways spanning high to very low emissions for CMIP7 applications.

• Dust aerosol substantially influences regional climate patterns by absorbing and reflecting radiation, acting as efficient ice-nucleating particles, and thus creating a dipole forcing pattern between ocean and land surfaces.
• Online dust schemes in CMIP6 struggle to represent the ~50% increase of dust aerosol in the industrial era and exhibit high inter-model variability. At the same time, recent field campaigns and observational products deliver novel constraints on long-wave properties, super-coarse particles and cloud interactions.
• Dust Plumes implements an up-to-date estimate of climatological distribution, optical properties and historical trend of dust into ICON-XPP, to deliver new estimates of forcing and climate response. 

• Oceans cover the majority of the planet, with sea salt strongly influencing present day and pre-industrial climates. However, improving simulated sea salt emissions has long been overlooked.
• Sea salt emissions vary by up to 7 orders of magnitude across Earth system models, are sensitive to the model’s accurate representation of the surface wind field, and depend strongly on the chosen wind-dependent parameterization.
• SeaPlume uses global aerosol optical depth reanalysis products to simplify the sea salt emission representation while capturing the temporal and spatial variability and remaining adaptable to different input data sources.