E-PEACE

Description

The Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) was a 2011 experiment by a team of US-based scientists off the coast of Monterey, California focused on improving understanding of cloud–aerosol interactions.

The experiment was conducted in July and August 2011. Persistent, low clouds (stratocumulus) form in the area at that time of year, making it possible to evaluate cloud–aerosol interactions in relatively stable atmospheric conditions.

The researchers added particles to the atmosphere by generating paraffin smoke from the deck of a ship and by releasing salt particles from a Twin Otter aircraft. They also measured emissions from ships passing through the study area during the experiment.

The team then used aircraft-based instruments and satellites to measure particle concentrations, cloud responses to the added particles, and changes in cloud properties (e.g., reflectivity). They compared their measurements to model predictions to improve computer simulations of cloud–aerosol interactions.

E-PEACE's findings are relevant for marine cloud brightening. The team found that smoke and particles from ships can increase cloud brightness. They further found that large salt particles can increase drizzle rates, which can decrease cloud lifespans.

Key Papers