2 nd IPWG Workshop, Monterey October The need for experimental data in support of IPWG research activities Bizzarro Bizzarri, CNR/ISAC, Roma, Italy Albin Gasiewski, NOAA/ETL, Boulder Co., USA Contents: Requirements from IPWG and CGMS for experimental data Shortest reminding of the GEM/GOMAS project The planned MW/Sub-mm airborne campaign over Europe

2 nd IPWG Workshop, Monterey October IPWG requirements for experimental data At the 1 st IPWG Workshop in Madrid (23-27 September 2002), the “Research Activities WG”, under the item “Future Sensors”, identified the need for experimental datasets in support of - the definition of future missions and - to feed the scientific simulation programmes. B. Bizzarri was charged to pursue the matter (Recommendation 1). Soon after, B. Bizzarri and A. Gasiewski started planning for the airborne campaign now being described.

2 nd IPWG Workshop, Monterey October CGMS recommendation The IPWG requirement was brought to the attention of the successive sessions of CGMS that finally, at its XXXII session (Sochi, Russia, May 2004), approved the following: Action CGMS recommends that Space Agencies support, as much as possible, the IPWG request for procuring experimental data sets (e.g. by airborne campaigns) to help cloud/precipitation modelling and instrument definition. A report on the support realised for this IPWG request should be given at CGMS XXXIII. Deadline: CGMS XXXIII.

2 nd IPWG Workshop, Monterey October S-Band Antenna for TT&C S-band antenna for LRIT NORTH DIRECTION Space Calibration Tube NADIR Solar Wing 3 -meter Antenna Star Sensors S-band Antenna for TT&C The GOMAS satellite Mass: 860 kg (“dry": 430 kg) Electrical power: 500 W Volume: 3.0 x 3.0 x 3.0 m 3 Data rate: 128 kbps (S-band, compatible with MSG LRIT).

2 nd IPWG Workshop, Monterey October GOMAS (Geostationary Observatory for MW Atmospheric Sounding) European sector (1/12 of disk) scanned each 15 minutes. Simultaneous retrieval of temperature profile, all weather and in clouds,30 km resolution humidity profiles, all weather and in clouds,20 km resolution cloud liquid/ice water total column and gross profile,20 km resolution precipitation,10 km resolution.

2 nd IPWG Workshop, Monterey October Atmospheric spectrum in the MW/Sub-mm range (Klein and Gasiewski, 2000). Preferred bands - for O 2 (temperature): 54 GHz, 118 GHz, 425 GHz; for H 2 O: 183 GHz, 380 GHz.

2 nd IPWG Workshop, Monterey October Incremental Weighting Functions (IWF) for the selected channels in the bands of oxygen (54, 118 and 425 GHz) and of water vapour (183 and 380 GHz). Note that the sensitivity of 380 and 425 GHz drastically drops in lower troposphere (Klein and Gasiewski, 2000).

2 nd IPWG Workshop, Monterey October Comparison between the 118/54 GHz profile ratio from the NAST-M microwave radiometer being flown on the NASA ER-2 aircraft and simultaneous EDOP Doppler radar reflectivity observation. Hurricane Bonnie at 17 GMT on August 26, 1998 (Tsou et al, 2001). The ratio 118/54 is unit in the absence of precipitation or above the precipitation cell, and reduces in the presence of precipitation because of higher attenuation from drops and impact from ice scattering at the higher frequency. The agreement between the two vertical cross- sections is striking. Horizontal maps of this information from GEO at 15 min intervals, will resemble a proxy rain radar operating over continental field of view, particularly over oceans and mountainous terrain.

2 nd IPWG Workshop, Monterey October Planning for an airborne campaign Objectives of a MW/Sub-mm airborne campaign in Europe are: To characterise the signature of clouds and precipitation in the MW and Sub-mm bands selected for GOMAS and GEM in respect of frontal rain, light rain and snowfall, in addition to convective rain considered to be enough characterised. To compare experimental precipitation observation by MW/Sub-mm sounding with conventional data observed by MW windows. This will, i.a., allow demonstrating the benefit of adding absorption channels to the baseline window channels of EGPM (European contribution to GPM). To contextually demonstrate the applicability of MW/Sub-mm to the study of cloud ice and water vapour in the Upper Troposphere / Lower Stratosphere (project CIWSIR, Cloud Ice and Water-vapour Sub-mm Imaging Radiometer).

2 nd IPWG Workshop, Monterey October GHz 118 GHz 183 GHz 380 GHz 425 GHz      (GHz)(MHz)(GHz)(MHz)(GHz)(MHz)(GHz)(MHz)(GHz)(MHz)                             optional/auxiliary     Bands and channels of GOMAS and GEM

2 nd IPWG Workshop, Monterey October (GHz)  (MHz) Polarisation (GHz)  (MHz) Polarisation (GHz)  (MHz) Polarisation (*)3000two  two  two  one  one two one  two  (*) Alternative: 150.0GHz   “Classical” channels for precipitation Sounding channels for improved observation over land including frontal rain, light rain and snowfall Bands and channels of EGPG (green boxes baseline, others optional)

2 nd IPWG Workshop, Monterey October “Cirrus”channels“Sounding”channels (GHz)  (MHz) Polarisation (GHz)  (MHz) Polarisation  two   two     one  one      one       one    one    Bands and channels of CIWSIR for cloud ice and water vapour in UT/LS

2 nd IPWG Workshop, Monterey October Scanheads of the NOAA/ETL Polarimetric Scanning Radiometer (PSR)

2 nd IPWG Workshop, Monterey October The “M-55 Geophysica” aircraft

2 nd IPWG Workshop, Monterey October The “M-55 Geophysica” aircraft

2 nd IPWG Workshop, Monterey October The “M-55 Geophysica” aircraft

2 nd IPWG Workshop, Monterey October Volumetric aspect of PSR (about 1 m 3, about 430 kg)

2 nd IPWG Workshop, Monterey October Bay I: volume 2,052 m 3, mass 360 kg - Bay II: volume 1,963 m 3, mass 430 kg - Bay III: volume 1,135 m 3, mass 100 kg

2 nd IPWG Workshop, Monterey October Status of planning - Conclusion A pre-feasibility study has been carried out informally by Russians and NOAA/ETL (Al Gasiewski) with the assistance of CNR/ISAC staff. NOAA/ETL has implemented the necessary modifications to the instrument to fit the M-55 Geophysica bay II. Interest to support the campaign has been generically expressed at instances by the Italian Space Agency (ASI), ESA, NASA, EUMETSAT and NOAA. Costs have been estimated as 900 k Euro for 60 flight hours across Europe. The nominal plan aims at a first campaign in mid-October to mid-December 2005 and a second one in Spring The purpose of presenting the plan to IPWG is to establish resonance with the CGMS Action within Space Agencies aimed at providing support to the IPWG activities. As mentioned, CGMS expects a report on the implementation of this Action at its next session (Tokyo, second half of 2005).