1. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 GEWEX DATA and ASSESSMENTS PANEL (GDAP) Jörg Schulz (Chair, GDAP) EUMETSAT Matthew McCabe (Vice Chair, GDAP) King Abdulla University of Science and Technology, Saudi Arabia on behalf of the GDAP with contributions from: Ralf Bennartz, Xavier Calbet, Ali Ershadi, Frank Fell, John Forsythe, Carlos Jimenez, Christian Kummerow, Rob Kursinski, Miaoling Liang, Maarit Lockhoff, Diego Miralles, Dominik Michel, Brigitte Mueller, Remy Roca, Sonia Seneviratne, Lei Shi, Marc Schröder, Tim Trent, Andi Walther, Eric Wood

2. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 GDAP Objectives Facilitate Data Products –provide a better understanding of variability and change of the water and energy cycles Product Quality Assessments –provide independent and transparent quality assurance for existing data records, to endorse the use and the credibility of data records to a broader community –includes the guidance of surface networks such as BSRN and GPCC delivering crucial data needed for assessments; Radiative Transfer Code Assessments –provide a new standard for assessing the performance and potentially certifying GCM-style SW and LW RT codes (shared with GASS), –comparison of canopy radiative transfer models under controlled experimental conditions. New Activities –Establish new products supporting new challenges (obs4mips, extremes, PROES, etc), e.g., high res precipitation climate data record from radar data.

3. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 Data Set Assessments performed by GRP/GDAP Soil Moisture – TBD -Discussion at GDAP 2015 Precipitation – GPCP and others -White paper for assessment available, GDAP 2015 Water Vapor – multiple data sets -Assessment underway (fifth workshop in Nov 2015 at CIMSS, Madison) Turbulent Fluxes: SeaFlux and LandFlux -SeaFlux assessment largely finished, lots of publications, reporting pending -LandFLux assessment largely finished, lots of publications, reporting pending Aerosols – GACP over ocean; land is TBD -Aerosol assessment underway with very limited progress Clouds – ISCCP (http://climserv.ipsl.polytechnique.fr/gewexca/) -Cloud assessment completed 2012 (WCRP Report No. 23/2012) Radiation – SRB (http://eosweb.larc.nasa.gov/GEWEX-RFA/) and Surface reference observations – BSRNhttp://eosweb.larc.nasa.gov/GEWEX-RFA/ -Radiation assessment completed 2012 (WCRP Report No. 19/2012) Precipitation – GPCP and Sfc gauge obs (GPCC) -First Assessment completed 2008 (WCRP-128, WMO/TD-No. 1430)

4. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 Water Vapour Assessment (G-VAP) Background To date a comprehensive and consistent assessment of long-term satellite based water vapour data records addressing GCOS ECVs has not been carried out (Past SPARC WAVACS covered parts); G-VAP fills this gap and will fully document each step of the analysis and related results; GDAP started G-VAP in 2011. The major objective of G-VAP is to inform users (science community, GDAP, agencies, PIs,…) on the strength and weaknesses of available data records; Main approach: consistent inter-comparison and comparison to ground-based and in-situ observations analysing variability/stability with focus on troposphere; Thus far, four workshops have been carried out. These have been hosted by: 1) ESA-ESRIN, 2) DWD, 3) CSU, 4) FUB; The fifth workshop will be at the SSEC, University of Wisconsin at 4+5 November 2015; Further details on G-VAP can be at www.gewex-vap.org.www.gewex-vap.org

5. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 Long-term analysis of TCWV Regions with distinct differences largely coincide among the standard deviation of the differences and in the mean absolute difference of the trend estimates. These are caused by break points, coincident with changes in the observing system. The time, the sign and the step size are typically a function of region and data record. On global ice free ocean scale the trend estimates among the different data records were found to be significantly different between the data records. Standard deviation Mean absolute difference in trend estimates

6. MOOG June 17, 2014 ECMWF/EUMETSAT ROM-SAF Workshop 547 hPa Specific Humidity Comparisons ECMWF & NCEP analyses don’t like really dry air General underestimate of very high humidity air except MERRA GPS, MERRA & AIRS agree well on very dry end in mid- troposphere NCEP & AIRS overestimate mid- humidity air ~5 km altitude, 30S-30N 2007 Kursinski et al., 2014

7. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 7 GEWEX Data and Assessments Panel (GDAP): Goal: Develop global observationally based products to allow independent water and energy cycle assessment (1984- 2007). MODEL Source of water Source of energy Short/Long-wave radiation SOIL VEGETATION ET SATELLITE OBSERVATIONS WATER SUPPLY ATMOS. DEMAND Sink for vapour ATMOSPHERE GEWEX Landflux 7 Courtesy of C. Jimenez and M. McCabe

8. KING ABDULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, SAUDI ARABIA Tower and Model Forcing Data Meteorological forcing and common parameters 8 Tower Data Flux tower and site information fromhttp://www.fluxdata.o rg/DataInfo/http://www.fluxdata.o rg/DataInfo/ Meteorology Vegetation height Radiation components LST from LWU Satellite based NDVI INTERCEPTION!!!??? Grid based data derived from a combination of reanalysis, satellite products and VIC model data

9. KING ABDULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, SAUDI ARABIA LandFLUX Version 0 Product Final V0 product based on four “candidate” LandFLUX models to be released in Fall 2015 Products is evaluated at local, regional and continental scale Further work is needed on developing consistent forcing data No single model performs well everywhere. An ensemble?? 9 SEBS PM PT GLEAM mm/yr

10. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 VariableSourceAfricaAustraliaEurasiaNorth America South America Global Land RunoffVIC 147227266237653288 PrecipitationGPCP 6447116156661561774 ET (Landflux) PM 553468358397971504 PT 470398322360827440 SEBS 530321362399875479 GLEAM 501485421448982530 AVERAGE 514418366401914488 Closure Runoff – P- avg(ET) 16±28-66±5817±28-28±236±62-3±42 Runoff – P- ET(PM) -56 (-8.7%) 16 (2.2%) -9 (-1.5%) 32 (4.8%) -63 (-4.0%) -18 (-2.3%) Sources of Estimates (mm/yr; 1984-2007)

11. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 New Assessments Started planning of new precipitation and soil moisture assessment by tasking Hiro Masunaga and Wouter Dorigo to develop assessment white paper with the community until next GDAP meeting (29 Sep – 1 Oct, 2015, Xiamen, China); Aim is to outline full assessment but to concentrate on items that are achievable within 2 years from the start.

12. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 Precipitation Assessment Foci –(a) Global and Regional Climatology (long-term mean and trend) –(b) Time series analysis in the context of different modes of climate variability –(c) Extremes –(d) Frozen precipitation –(e) Structural Errors Link up with MOUNTerrain from GHP

13. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 Soil Moisture Microwave Products  SMOS mission extended until February 2017  Copernicus Sentinel-1 and SMAP launched 2014  New quasi operational soil moisture products from AMSR2, Feng-Yun 1B  Large interest in soil moisture workshops  ESA CCI Soil moisture product has over 1300 registered users  Increasing use of soil moisture for improving precipitation products Brocca et al., 2014, JGR]

14. WDAC 4 ECMWF, Reading, UK, 2-3 July 2015 Conclusion  GEWEX data set assessments as shown for water vapor and evapotranspiration help to further understand issues in data records and facilitate further development;  New assessments planned on precipitation and soil moisture;  Constructing an integrated product using the GEWEX standard products is an enormous task:  Basic building blocks of integrated Product: Ts, T(z), q(z) are not as good as hoped for. Large differences between products and little in terms of absolute validation.  Integrated product is a way forward in that the very interdependence that makes it difficult to produce, is also a very strict QC procedure.