The continuity of atmospheric variables data records is central to the understanding of the Earth atmosphere trends and the response to solar cycle variations on longer time scales. Current space missions targeting stratospheric and mesospheric observations are phasing out in the next few years. As a consequence, an observational time gap has already started that will seriously harm the continuity of long-term records. This gap must be covered to avoid difficulties in secular changes determination and inconsistencies in multi-instrument data sets due to missing opportunities for cross-validation. Within this panorama, the development of ground-based instrumentation in support of space-based efforts and to enhance their scientific return is important. Airglow imagers play here an significant role (Garcia-Comas et al., 2017) because their reachability favors excellent systematic calibrations compared to satellites. Thanks to their very high temporal resolution, synergies with satellite data also overcome the limitations of both types of observations, particularly for interpretation of waves and sporadic events at regional scales (Lopez-Gonzalez et al., 2017). 

The portraits of the MLT structure by circulation models and of its change by climate forecastings rely upon a good knowledge on GWs (Smith et al., 2017). Larger attention is being paid to their manifestation at regional scales. GWs are resolved from ground airglow data, from which their properties and their variability can be derived. Information on GW vertical propagation may also be achieved from observations of contiguous atmospheric layers. Combination with other ground instruments and satellite data is used to understand GW regional behaviour in the context of the surrounding atmosphere. 

A team of IAA-CSIC engineers, lead by Dr. García-Comas and Dr. López-González and in colaboration with the York University, are constructing the Multi-spectral Imager of Mesopause Airglow (MIMA) for monitoring the mesopause and its variability, as support for space-based instrumentation, and for studying regional GWs. The instrument is funded by the Ministry of Science of Spain through a competitive call. MIMA is a spectrometer that will continuously image the nighttime airglow and temperatures, allowing for the analysis of regional GWs, PWs and tides around the mesopause. It is a cost-effective instrument, heritage of the Spectral Airglow Temperature Imager (SATI; Sargoytchev et al., 2004), with enhanced performance, sensitivity, temporal and spatial resolutions, and extended spectral coverage. MIMA will stand at the Observatorio de Sierra Nevada relieving SATI (operating since 1998) and thus filling the gap the later will eventually leave over Eastern Andalusia within the Network for the Detection of Mesopause Change (NDMC). Fully automatic and remotely operated, the instrument is designed to fulfill stability requirements within 0.2% per decade that will allow measuring trends accurately. It is designed to be affordably maintained, repaired and repeated. MIMA is planned to cover at least two solar cycles of operation (with proper maintenance), for addressing satellite biases and drifts, and coverage of discontinuous space-based observations. It is possible to clone it and install it at other locations in the future. MIMA’s kick-off is planned for late 2019. 

For further information please contact maya@iaa.es or mjlg@iaa.es.