The formation and evolution of Titan's winter polar vortex.
Nature Communications Nature Publishing Group 8:1 (2017) 1586
Abstract:
Saturn's largest moon Titan has a substantial nitrogen-methane atmosphere, with strong seasonal effects, including formation of winter polar vortices. Following Titan's 2009 northern spring equinox, peak solar heating moved to the northern hemisphere, initiating south-polar subsidence and winter polar vortex formation. Throughout 2010-2011, strengthening subsidence produced a mesospheric hot-spot and caused extreme enrichment of photochemically produced trace gases. However, in 2012 unexpected and rapid mesospheric cooling was observed. Here we show extreme trace gas enrichment within the polar vortex dramatically increases mesospheric long-wave radiative cooling efficiency, causing unusually cold temperatures 2-6 years post-equinox. The long time-frame to reach a stable vortex configuration results from the high infrared opacity of Titan's trace gases and the relatively long atmospheric radiative time constant. Winter polar hot-spots have been observed on other planets, but detection of post-equinox cooling is so far unique to Titan.Seismic Coupling of Short-Period Wind Noise Through Mars' Regolith for NASA's InSight Lander
SPACE SCIENCE REVIEWS 211:1-4 (2017) 485-500
The DREAMS experiment flown on the ExoMars 2016 mission for the study of Martian environment during the dust storm season
2017 IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) IEEE (2017) 249-255
Abstract:
The DREAMS (Dust characterization, Risk assessment and Environment Analyser on the Martian Surface) experiment on Schiaparelli lander of ExoMars 2016 mission was an autonomous meteorological station designed to completely characterize the Martian atmosphere on surface, acquiring data not only on temperature, pressure, humidity, wind speed and direction, but also on solar irradiance, dust opacity and atmospheric electrification, to measure for the first time key parameters linked to hazard conditions for future manned explorations. Although with very limited mass and energy resources, DREAMS would be able to operate autonomously for at least two Martian days (sols) after landing in a very harsh environment as it was supposed to land on Mars during the dust storm season (October 2016 in Meridiani Planum) relying on its own power supply. ExoMars mission was successfully launched on 14th March 2016 and Schiaparelli entered the Mars atmosphere on October 20th beginning its `six minutes of terror' journey to the surface. Unfortunately, some unexpected behavior during the parachuted descent caused an unrecoverable critical condition in navigation system of the lander driving to a destructive crash on the surface. The adverse sequence of events at 4 km altitude triggered the transition of the lander in surface operative mode, commanding switch on the DREAMS instrument, which was therefore able to correctly power on and send back housekeeping data. This proved the nominal performance of all DREAMS hardware before touchdown demonstrating the highest TRL of the unit for future missions. This paper describes this experiment in terms of scientific goals, design, performances, testing and operational capabilities with an overview of in flight performances and available mission data.Composite infrared spectrometer (CIRS) on Cassini: publisher's note.
Applied optics 56:21 (2017) 5897
Abstract:
This publisher's note renumbers the reference list in Appl. Opt.56, 5274 (2017)APOPAI0003-693510.1364/AO.56.005274.Composite infrared spectrometer (CIRS) on Cassini
Applied Optics 56:18 (2017) 5274-5294