The Network for the Detection of Mesopause Change (NDMC) concentrates at present on monitoring the upper mesosphere (altitudes of ca. 80-100 km); in the mid-term the focus is to be expanded to include the entire mesosphere. Currently, 47 science institutions in 21 countries participate in this effort. NDMC is associated with the WMO’s GAW program and the Network for the Detection of Atmospheric Composition Change (NDACC), and is meanwhile already accepted as an official component of the “Climate” section of GEO. NDMC was founded in 2007 and is coordinated by DFD’s Atmosphere department with the support of the state of Bavaria and in consultation with the University of Buenos Aires, Argentina.
The team operates, and is further developing, the Ground-based Infrared P-branch Spectrometer (GRIPS), which is integrated into NDMC. At present a GRIPS instrument is installed at the Schneefernerhaus Environmental Research Station UFS on the Zugspitze mountain and at DLR-DFD in Oberpfaffenhofen. Additional. GRIPS instruments, and accordingly more NDMC measurement stations, are planned for installation in the coming years. Automatically, and night after night, GRIPS remotely measures with great precision and high temporal resolution the OH* temperature in the mesopause region (ca. 80-90 km altitude). Use is made of the phenomenon of “airglow,” which is generated by photochemically excited hydroxyl molecules (OH). An O2 photometer with the name TANGOO (Tilting filter spectrometer for Atmospheric Nocturnal Ground-based Oxygen & hydrOxyl emission measurements) will complement GRIPS by additionally measuring at an altitude of ca. 90-100 km. This system is also to be linked to a powerful infrared camera (the All-Sky Airglow Imager).
One goal of the measurements is early detection of climate signals, for example for monitoring the effectiveness of the Kyoto Protocol. Climate changes should be recognizable at these altitudes at an early stage since the anthropogenic component of the greenhouse gas effect is, according to the latest research, stronger by one to two orders of magnitude in the mesosphere, and thus easier to detect there than at lower atmospheric levels, the reason being the very effective cooling down of the radiation (“cooling-to-space”). Basic research is also part of the regular work with GRIPS and TANGOO being undertaken by the WDC-RSAT/NDMC team. The location of these instruments on the Zugspitze mountain makes it possible to study atmospheric gravity waves right where they are being generated. This work will contribute to improving gravity wave parameterization in climate models and thereby enhancing their forecasting quality. A GRIPS upgrade will allow detection of the infrasound waves generated, for example, by active volcanoes, tsunami and storms, facilitating the rapid identification of natural hazards. For this purpose a powerful pattern recognition procedure is being developed. In cooperation with industry, this system is planned for use in so-called next-generation multihazard early warning systems of the type now being designed by the WMO on behalf of the United Nations. In the future GRIPS will be increasingly employed to validate satellite measurements, for example from ENVISAT-SCIAMACHY and TIMED-SABER, as well as to verify climate models such as HAMMONIA, by comparing GRIPS measurements with modeled data. Other main areas of research carried out by the WDC-RSAT/NDMC team include investigating the influences of solar signals on the atmosphere, and the large-scale dynamics of the mesopause region, particularly the activity of planetary waves.