December 31, 2010, marked the last official day of data collection for the Clouds, Aerosol, and Precipitation in the Marine Boundary Layer field campaign on Graciosa Island in the Azores. In its longest deployment to date, measurements obtained by the first ARM Mobile Facility (AMF1) during the 20-month campaign are providing important new information to scientists about the structure and variability of the remote marine boundary-layer cloud system and the factors that influence it.

Notably, the data illustrate the impact of drizzle on low clouds, particularly during “extreme drizzle events” resulting in the near–complete removal of cloud forming particles. Preliminary data analysis also show new measurements of the vertical dynamical structure of trade cumulus clouds observed with the cloud radar. Researchers will use the abundance of data collected by all the AMF1 instruments to study the processes controlling the radiative properties and microphysics of marine boundary-layer clouds, a high priority science question. A workshop for interested scientists is in the planning stages.

Approximately one year into the deployment, the AMF1 team welcomed a new onsite technician, Carlos Sousa. He was born on Graciosa but spent many years in Boston, so his language skills proved very useful during the campaign. Under the guidance of AMF1 lead technician Mike Alsop, one of Sousa’s first major tasks was to install and remove a collection of radiometers (also designed and built by Alsop) on nearby Pico Island for a supplemental campaign, the Above cloud Radiation Budget Study at Pico Observatory.

Mark Miller, AMF1 site scientist and principal investigator for the Pico Study, extended his thanks to Kim Nitschke, the AMF1 site manager, Alsop, and Sousa for doing “an amazing job, as always.” The AMF1 team is now in the midst of disassembling the instrumentation and packing it up for its next campaign: the Ganges Valley Aerosol Experiment in Ganges Valley, India, scheduled to begin this spring. Follow their progress on the AMF1 blog.