The Support to Aviation Control Service (SACS) aims at supporting the Volcanic Ash Advisory Centers. This is achieved by delivering NEAR REAL-TIME data of SO2 and volcanic ash derived from satellite measurements. The SACS multi-sensors system also include

SACS has a long history, building on the original TEMIS service but becoming operational in 2006, and has been part of, and integrated with, several other projects since then, including EUNADICS-AV. KNMI has and is contributing with providing satellite data as well as integrating the SACS service into the TEMIS service.

Volcanic eruptions may eject large amounts of ash (aerosols) and trace gases such as sulphur dioxide (SO2) into the atmosphere. These ejecta can have considerable impact on the safety of air traffic and on human health. Ground-based monitoring is carried out at only a limited number of volcanoes: most volcanoes are not monitored on a regular basis, in particular the remotely located volcanoes.

Global observations of SO2 and aerosols derived from satellite measurements in near-real time (= satellite data products available three hours after the observations are made) therefore provide useful complementary information to assess the possible impact of volcanic eruptions on air traffic control and public safety.

The Support to Aviation Control Service (SACS) focuses on the timely delivery of SO2 data derived from different satellite instruments, measuring in the UV/Visible (GOME-2, SCIAMACHY and OMI) and the InfraRed (IASI and AIRS) on board of polar-orbiting satellites.

Since most volcanic eruptions emit both SO2 and ash, the precence of SO2 can serve as a marker for volcanic ash clouds, at least in the first few days after an eruption. The Service thus allows for monitoring the occurrence, extension and motion of volcanic plumes.

On the basis of selection criteria of exceptional SO2 concentrations, the Service issues a notification by e-mail to interested parties, with a reference to a dedicated page at the website with the SO2 map of the event and (links to) further information on the event. Though SACS is primarily aimed at supporting the Volcanic Ash Advisory Centres (VAACs) in their tasks. These centres are the official organisations responsible for gathering information on volcanic clouds. Anyone interested can subscribe to the email notification service of SACS.

SACS is integrated with the KNMI TEMIS service and will also be integrated within the EUNADICS-AV service.