PREMIER/STEAM-R Science Support Study

The research proposed covers two aspects: - Quantitative assessment of tropospheric limb-sounding at mm-wavelengths - Scientific support for STEAM-R instrument definition Quantitative assessment of tropospheric limb-sounding at mm-wavelengths ------------------------------------------------------------------------------------------------------------ Data acquired by MARSCHALS, CRISTA-NF and MIPAS-STR from the SCOUT campaign in Darwin, Australia in Dec'05 will be analysed in comparison to correlative observations in order to demonstrate the capabilities of mm-wave limb-sounding of the troposphere at a sub-tropical location and its synergy with IR limb-sounding. This will allow a significant UK contribution to be made to consolidating the scientific case for STEAM-R within the PREMIER mission, and would complement other supporting scientific studies for PREMIER which may be initiated by the MAG. This analysis will focus on two key issues which RAL is well-placed to address: 1) Derivation of tropospheric trace gas and cirrus properties through an integrated approach 2) Sensitivity to instrumental factors and implications for the design of STEAM-R Following upgrades to the instrument, MARSCHALS will be deployed on ground in winter / spring 2007/8 or on the Geophysika aircraft during the next planned campaign in mid-2008. The latter is contingent upon a decision by the European consortium which operates the Geophysika for scientific purposes, due to be made on in late October. Prompt analysis of new data to demonstrate these points is essential, given the timetable of the pre-Phase A studies and the mission assessment process. Scientific support for STEAM-R instrument definition ---------------------------------------------------------------------------- Radiative transfer and retrieval simulations will be conducted in support of STEAM-R definition: - To address scientific issues and/or design issues identified by the PREMIER MAG or STEAM-R instrument team during the pre-Phase A period and to update the instrument specification in the MRD. - To position the UK to participate on the science side in subsequent project phases and to develop a L2 processor RAL is extremely well placed to carry out retrieval simulations in support of all aspects of the STEAM-R instrument development, thanks to its existing retrieval simulation software, which has been developed though previous ESA studies (including the 2-D retrieval scheme which accounts for scattering by cloud). Some adaptation of these tools will be necessary and appropriate funding is requested here (see costing below).Close co-operation with partners in Sweden and elsewhere will be essential during pre-Phase A. Although communication will mostly be by e-mail and telecon, it will also be necessary to attend project meetings in person.