From SCIAMACHY to CarbonSat and SCIA-ISS
Burrows, John P.; Bovensmann, Heinrich; Richter, Andreas; Gerilowski, Konstantin
University of Bremen, GERMANY

The consequences of pollution now extend from the local to the global scale. The global observation of atmospheric constituents (trace gases, aerosol, and cloud), meteorological parameters (temperature, pressure and wind) and surface parameters provides unique insight into the earth system and its biogeochemistry. In addition these measurements provide the evidence base for the development of environmental policy. The Scanning Imaging Absorption spectrometer for Atmospheric CHartographY, SCIAMACHY, was proposed in July 1988 for flight on the then Polar Orbiting Earth Mission 1, POEM-1, which later became ESA Envisat. SCIA-mini was proposed in December 1988 in answer to the call for atmospheric constituent measurements for ERS-2. SCIA-mini was selected for ERS-2 but was descoped and renamed to become the Global Ozone Monitoring Experiment, GOME, a nadir only viewing instrument. GOME was launched successfully in April 1995 and made measurements successfully until ERS-2 was decommissioned in 2011. Its success led to the selection of GOME-2 for the ESA/EUMETSAT operational meteorological series of Metop platforms. Envisat was launched with SCIAMACHY as part of its payload in 2002. SCIAMACHY measured successfully until Envisat failed suddenly and unexpectedly on the 8th April 2012. Metop A was launched in October 2006 and Metop B in November 2012. The orbits of ERS-2, Envisat and Metop are sun synchronous having equator crossing times of 10:30, 10:00 and 09:30 respectively. SCIAMACHY made measurements in alternate limb and nadir viewing during the majority of the orbit as well as solar and lunar occultation. Its measures in 6 spectral channels contiguously from 214 nm to 1750 nm and in two short wave infrared from 1940 to 2040 nm and from 2265-2380 nm. GOME and GOME-2 make nadir measurements in four spectral channels from 232 to 793 nm. GOME-2 is planned to be followed by the operational instrument Sentinel 5 around 2020, there is also a Sentinel 5 Precursor instrument from 2016. The first geostationary satellite mission Sentinel 4, which was originally proposed as GeoSCIA, is planned for launch on MTG in the 2018/2019 period. However these instruments have limitations in their temporal and spatial sampling. New mission are urgently needed to build on the heritage of SCIAMACHY and improving on the spatial resolution and temporal sampling. CarbonSat is one such potential mission which focuses on making high spatial resolution measurements of carbon dioxide, CO2, and methane, CH4. This builds on the low spatial resolution measurements of SCIAMACHY to make high spatial resolution measurements and has been selected for Phase A B1 studies for the ESA Earth Explorer Mission 8. The SCIA-ISS instrument is part of the potential Anu Apollo mission, which is a joint Japanese German and American scientific initiative, aiming to provide high spatial resolution trace gas measurements form the ISS. One focus of the presentation is to show highlights from the GOME and SCIAMACHY missions. Another is the lack of limb and occultation measurements with the loss of Envisat. The need for the new instruments missions will such as CarbonSat and SCIA-ISS be highlighted.