Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station Torsten Neubert Ib Lundgaard Rasmussen National Space Institute
Overall Objective Thunderstorms and their relation to atmospheric processes and a changing climate Thunderstorm over Mali, February 5, 2008, seen from the ISS
ASIM Themes ASIM will observe the atmosphere above thunderstorms: Electric discharges sprites, jets, elves, X-rays Gravity waves Clouds and water vapour Chemistry Giant (Su et al., 2005) Clouds in the mesosphere Gravity waves in the mesosphere
ASIM on the International Space Station ASIM is primarily a spectroscopic imaging mission The instruments observe spectral bands Observations are taken from space above the clouds From the lowest orbit available (400 km)
ASIM instruments MMIA (Modular Multispectral Imaging Array) 4 cameras and 4 fotometers look forward towards the limb 2 cameras and 2 fotometers look dornwards towards the nadir MXGS (Modular X- and Gamma Ray Sensor) 1 detector looking downwards towards the nadir
Optical Instruments MMIA FOV Pixels Pixel resolution Time resolution Spectral bands Cameras Nadir: 80 o x 80 o Limb: 20 o x 20 o 1024 x 1024 Nadir: 0.3-0.4 km Limb: 0.4-0.6 km 40 ms LC1: 337.0 nm LC2: 391.4 nm LC3, 660-740 nm LC4: 762.4 nm NC1: 337.0 nm NC2: 777.4 nm Photometers Nadir: 80 o x 80 o Limb: 20 o x 20 o 100 khz LP1: 337.0nm LP2: 391.4 nm LP3: 660-740 nm LP4: 236.6 nm NP: 337.0 nm NP2: 145-300 nm
Gamma-ray detectors ASIM γ RAY DETEC Energy range 1 (nadir) 7 500 kev Effective area Energy resolution Detector Backgr. 1032 cm 2 < 10% 1000 counts/s
International Team Payload Team University of Valencia, Spain (MXGS) University of Bergen, Norway (MXGS) (Platform, MMIA, MXGS) Terma, Denmark (Main Contractor) Internationale Science Team: 29 countries 70 research groups
ASIM Status Phase B midterm review May, 2008 Phase B end January, 2009 Phase C/D negotiations following ESA ministerial Conference in December, 2008 ESA negotiating with JAXA on launch on HTV Launch 2012
Preparations Needed ground instrumentation Radar and lightning detection Optical stations 3D-lightning networks EM waves Infra sound Ionospheric perturbations Balloon campaigns Being prepared with CNES/FP7 Laboratory experiments Model development
The European Segment of World Sprite-Watch Partnership
Mapping National Space Institute of tropical thunderstorm turrets. Niels Larsen, Tina Christensen and Johanne K. Nielsen Danish Meteorological Institute
Role of deep convection in the Tropical Tropopause Layer (TTL) Does dehydration happen on large scale? e.g. Fueglistaler et al. JGR (2004) Water vapor saturation mixing ratio (smr) of air entering the stratosphere, averaged at minimum smr point along ECMWF trajectories. Contours show density of trajectories. -or does it happen in connection to local thunderstorms? e.g. Sherwood and Dessler JAS (2001) -or do tropical thunderstorms actually hydrate the lower stratosphere?
Satellite borne radar* Tropical Rainfall Monitoring Mission * Does not see small particles Liu and Zipser JGR, (2005)
Use of ASIM platform Limp directed optical imaging camera Daytime: Observations triggered by cloud altitude. Nightime: Clouds illuminated by lightning?. Cloud altitude and and cross section area, location and time. Automatic detection algorithms, needs to be developed.
Outcome Statistical description of tropical cloud altitudes Overshooting thunderstorms' contribution to water budget Annual variablility of deep convection Geographical variability. ASIM cloud altitudes In situ observations Overshoot statistics Microphysical Modeling Assessment of global convective transport
Summary Tropical deep convective events may be a source to stratospheric water vapor which is known to have a strong greenhouse forcing and influence the ozone balance. The ASIM platform can improve the present knowledge about tropical deep convective events. We propose that the limp directed optical imaging camera is set up to perform onboard statistics (and keep samples) where clouds are observed above a certain altitude
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