Fewer CCNs since the Saharan dust vanished

Yesterday, the helicopter together with ACTOS and SMART-Helios flew profiles and legs over the Atlantic ocean near by the east coast of Barbados in order to measure the dynamical, thermodynamical and microphysical properties of the transition layer (atmospheric layer between marine boundary layer and trade wind inversion) under cloud-free conditions. Also 5 dolphin flights were carried out between 1100 and 2500 ft to analyze the top of marine boundary layer. The miniature-Cloud Condensation Nucleus (CCN) counter on ACTOS as well as the ground-based CCN measurements on Ragged Point showed much less CCN numbers of about 50-100 than on 06.04.2011 (first test flight). During this flight there was a Saharan dust layer with a maximum height of about 3 km (measured by the MPI-lidar on Deebles point) and 200 CCNs were measured.