To maximize the scientific benefits from the mission, an optimization of the A-Train formation was proposed by the science teams.
The proposed changes in the A-Train configuration include phasing of the Aura and CloudSat platforms, and a pitch change to the CALIPSO.
The CALIPSO pitch change amounts to 3o, in a pursuit to reduce reflections from oriented crystals
thatproduce strong backscatter signals
with no depolarization and low extinction. The pitch change requiresa 5-second increase of theseparation between CloudSat and CALIPSO, in order to maintain their footprints overlapped. This maneuver has already been implemented by advancing CloudSat forward.
Concerning Aura, it is envisioned that it will be left to driftahead and thus reduce its separationfrom Aqua by about 7-8 minutes. The sought effect is to relocate the MLS footprint under CloudSat and CALIPSO, as well as to reduce the time lag between Aura and Aqua observations of rapid atmopsheric phenomena. The Aura phasing is a longer process that is expected to be finalized by the summer of 2008.
The changes to the A-Train configuration will bring numerous benefits, among them are reducing of ambiguities associated with the time difference, better combining of multi-instrument retrievals of atmospheric water vapor, temperature, clouds and aerosols, and better understanding of the microphysics of clouds and their interactions with aerosols.
These images, collected over the South Pole, give an insight intothe benefits of the collocation of MLS and CloudSat and CALIPSO, that presently in the original state of the A-Train configuration are possible to exploit mostly at very high latitudes.
MLS and CALIPSO clearly pick up a stratospheric feature, while CloudSat reveals the structure of lower tropospheric clouds. Once the Aura (MLS) phasing is accomplished, collocated studies like this will be possible along all orbits, not at the poles only.