High-altitude aircraft help unravel complexities of atmosphere   Two high-altitude research aircraft, the Russian Geophysica and the German DLR Falcon, along with the technical and scientific teams in northern Australia for an airborne campaign to study chemistry and dynamics in the upper atmosphere.   The PREMIER mission aims to advance our understanding of the processes that link trace gases, radiation and chemistry in the upper troposphere and lower stratosphere. The instrumentation will consist of an infrared limb-imaging spectrometer and a millimetre-wave limb-sounder.   The MARSCHALS instrument in the belly pod of the high-altitude aircraft Geophysica. The instrument sounds the mid and upper troposphere and lower stratosphere in limb geometry to acquire high-resolution vertical profiles of atmospheric gases. During the campaign in northern Australia, it took measurements of water vapour and ozone, and demonstrated full performance in the presence of cirrus cloud. It is currently being upgraded to also observe carbon monoxide and other trace gases relevant for understanding of the chemistry and dynamics of this important atmospheric region. The instrument development was led by Rutherford-Appleton Laboratories in UK. It is a demonstrator for the STEAM-R millimetre-wave limb-sounder, which would be provided by the Swedish National Space Board for flight on the PREMIER satellite.   Typical shape of a tropical convective cloud. Within these cloud systems, large amounts of tropospheric air are lifted up into the stratosphere, transporting water vapour (and other gases) into the otherwise very dry stratosphere and thereby affecting chemical and radiative processes in the tropopause region and stratosphere.   GLORIA-AB, which is an instrument that takes images in the infrared spectra, is currently being developed by the Jülich and Karlsruhe Research Centres in Germany. The sensor will take measurements at different spectral resolutions and hence address different scientific priorities that require either a larger set of atmospheric constituents (for which higher spectral resolution is needed) or higher spatial resolution (implying faster measurement in lower spectral resolution). These same concepts will also be used for the infrared limb-sounder that could be carried on the PREMIER mission. The first scientific campaign of the airborne instrument is planned for early 2010. Release date: 3 December 2009