Observation of Fine-Scale Filamentary Structures by the GLORIA Limb Imager
Guggenmoser, Tobias¹; Ungermann, Joern¹; Blank, Joerg¹; Grooss, Jens-Uwe¹; Vogel, Baerbel¹; Kleinert, Anne²; Kaufmann, Martin¹; Friedl-Vallon, Felix²; Oelhaf, Hermann²; Preusse, Peter^1
1Forschungszentrum Juelich GmbH, GERMANY; ²Karlsruher Institut fuer Technologie, GERMANY

The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) has been developed jointly by Forschungszentrum Jülich and Karlsruher Institut für Technologie. It serves as a demonstrator for PREMIER, a candidate for ESA's Earth Explorer 7, and was first deployed during the ESA co-funded campaign ESSENCE. Here, we focus on results from the German combined TACTS/ESMVal measurement campaign, which was conducted during August and September 2012. Its objective was to improve our understanding of the UTLS region using a combination of airborne in situ and remote sensing devices on board the research aircraft HALO.

As an imaging FTS in the thermal infrared range, GLORIA is capable of recording a whole array of over 6000 interferograms with 128 tangent altitudes at once. This makes vertical scanning unnecessary for the retrieval of altitude profiles. Generally capable of a spectral resolution of 0.125 cm-1, in the "dynamics mode" GLORIA records shorter measurements with a spectral resolution of 1.25 cm-1, but pans horizontally between 45° and 128° with respect to the flight direction. This allows for tomographic inversion of 3D resolved atmospheric fields in closed flight patterns. Tomographic inversion is based on the JURASSIC2 software package developed by Jülich. JURASSIC2 includes a fast forward model and a sophisticated inversion library capable of handling problems with millions of unknowns.

During TACTS/ESMVal, intensive Rossby wave breaking generated a large number of filamentary structures which facilitate mixing between subtropical/mid-latitude and polar air across the subtropical jet. GLORIA detects these filaments in various trace species, such as HNO3 and ozone (indicating stratospheric air masses) and PAN, water vapor and freons (indicating tropospheric air masses). Filaments smaller than 1km in the vertical have been observed. These structures are presented in curtains along the flight track and interpreted with comparisons to potential vorticity and model calculations. Two examples of tomographic retrieval demonstrate the 3D reconstruction of filamentary structures.