1. APOLLO Cloud Properties Challenges and Requirements after 28 Years of Experience at DLR Lars Klüser, Niels Killius and Gerhard Gesell www.DLR.de Chart 1APOLLO Cloud Properties Gesell et al 2015-04-20

2. The history of APOLLO AVHRR Processing scheme Over cLouds Land and Ocean -1986 Development at Robert Hooke Institute by Roger Saunders and Theo Kriebel (uses 5 AVHRR channels and allows quantitative analysis) -1987 Implementation of a modular Version into ISM at DLR (ISM Interactive System Meteorology based on McIDAS of SSEC) -1987 Implementation of snow/ice/cloud separation -1991 Development of a standalone UNIX-Version -1995 Adaptation to ATSR data -1997 Start of the operative processing for a „European Cloud Climatology“ -2003 Implementation into the operative processing chain of DFD -2003 Start of an NRT-service of APOLLO-based images on wdc.dlr.de for the support of synoptic weather view -2004 Adaptation to SEVIRI -2005 and later further adaptations and mostly minor improvements www.DLR.de Chart 2APOLLO Cloud Properties Gesell et al 2015-04-20

3. Projects with contributions from APOLLO -PAGODA (Project for ATSR and GOME data application – national project - ATSR) -ECC („European Cloud Climatology“ – DLR collection of cloud parameters - AVHRR) -CLOUDMAP2 (cloud parameters – AVHRR/MODIS) -COBI (Cold Bias in Atmosphere General Circulation Models – national project - AVHRR) -SYNAER (aerosol parameters – ATSR/AATSR) -CONTRAILS (contrails „climatology“ - AVHRR) -WISENT (Energy Meteorology (solar power) – national project - SEVIRI) -HELIOSAT (solar energy - SEVIRI) -HGF EOS (aerosol-cloud interactions, AATSR) -ESA CCI Cloud (cloud parameters – AVHRR) -ESA CCI Aerosol (aerosol parameters – AATSR) -MACC-III (solar energy estimations – SEVIRI) www.DLR.de Chart 3APOLLO Cloud Properties Gesell et al 2015-04-20

4. Calibration in APOLLO and generated datasets -Up to N-14 calibration and its administration within APOLLO – from N-15 up to now L1b-input into APOLLO (reflectances and temperatures, radiances for CH3B) -Within DFD utilization of calibration tools provided by Seaspace-TeraScan and archived NOAA- NESDIS calibration coefficients for AVHRR – up to N-14 also other ways gone -For (A)ATSR and SEVIRI external sources of calibration (SCENES-SW for SEVIRI) -ECC based on all archived AVHRR/HRPT data at DFD -AVHRR processing chain cloud masks and products based only on the operational platforms -Products generated for the NRT-service on wdc.dlr.de (AVHRR) -Products based on SEVIRI for solar energy projects (daytime only from 2004 onwards) www.DLR.de Chart 4APOLLO Cloud Properties Gesell et al 2015-04-20

5. Shortcomings and need for a major re-programming www.DLR.de Chart 5APOLLO Cloud Properties Gesell et al 2015-04-20 -No consistent calibration convention over all platforms and sensors -Old-fashioned coding and partly un-optimized run-time environment -Different versions for different sensors of the AVHRR heritage -Not including some of the latest retrieval methodologies for cloud parameters -No complete datasets for all archived AVHRR/HRPT data at DFD available up to now  Needs a re-coding and re-implementation and to be updated with the latest methodologies  For TIMELINE this update is neccessary  TIMELINE is the suitable occasion and environment to do this providing e.g. consistent calibration etc   APOLLO  APOLLO_NG

6. APOLLO  APOLLO_NG improvements and new features www.DLR.de Chart 6APOLLO Cloud Properties Gesell et al 2015-04-20 -Probabilistic cloud detection -Cloud probability is new diagnostic variable and allows for cloud mask adaptation based on required degree of confidence -Probabilistic retrieval of cloud optical depth, effective radius and thermodynamic phase directly yields uncertainty for each variable -CTT retrieval based on IR optical depth (with  ir =  vis /2.13) and thus also for cirrus

7. APOLLO_NG examples and outlook www.DLR.de Chart 7APOLLO Cloud Properties Gesell et al 2015-04-20 cloud probability cloud OD cloud top R eff cloud OD uncertainty July 15, 2008 AVHRR on NOAA-18 -APOLLO_NG already tested for: AVHRR, AATSR, SEVIRI, VIIRS -Contributions to: TIMELINE, Aerosol_CCI, MACC-III, CSP-FoSYS, GlobTemp RR, …

8. www.DLR.de Chart 8APOLLO Cloud Properties Gesell et al 2015-04-20 APOLLO_NG examples and outlook