CMUG Meeting 30102018 F Ardhuin LOPS 1 France

CMUG Meeting, 30/10/2018 F. Ardhuin, LOPS 1, France & J. R. Bidlot, ECMWF, J. Stopa, Univ. Hawaii 1 LOPS is the new home of the Ifremer remote sensing group ESA UNCLASSIFIED - For Official Use

1. Feedback for CMUG session 1. The significant wave height (Hs or SWH) is our prime variable but it does not say all. . . Other parameters : mean square slope, full spectrum proxy / signature of forcing : wind, currents, sea ice ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 2

1. Feedback for CMUG session 1. Sampling issue. . . CCI phase 1 ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 3

1. Feedback for CMUG session The CCI v 0 data will tell more than old (Globwave) → higher resolution → current impacts (see Quilfen et al. RSE 2018) ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 4

2. User requirements starting from GCOS-200 and more recent OOPC discussion - « Frontiers in Marine Science » paper to be presented at Ocean. Obs'19 - discussion at UCM 1 + Ocean. Obs'19 + online survey extremes … ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 5

3. Products, user needs, CRG applications Debate on wave height trends : Young et al. (2011). . . (1985 -2008 trend is not secular) ESA UNCLASSIFIED - For Official Use Mori et al. (2010), from models ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 6

3. Products, user needs, CRG applications Applications : - validation of models for extremes (Rascle and Ardhuin 2013) - blending models & CCI data for trends (Stopa et al. , submitted) ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 7

4. Integration with other ECVs & gaps - Sea ice concentration: obvious forcing for wave models + feedback (waves in ice observations with Sentinel 1) - waves as a proxy for winds & storminess (e. g. Hansen et al. 2016) - Link with sea level and « total sea level at coast » : people only care about SLR at the coast … - use of radiometer data (SMOS …) for surface roughness → wave breaking - better Hs → better sea level (e. g. Sandwell and Smith GJI 2005) ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 8

5. Uncertainties in products - Experience with triple-collocation (model + sat. + in situ) → building error models that are function of measured parameters - Specific for trends : investigation of consistency, in particular with seismometers (Stopa et al. , submitted) - much to learn from other ECVs ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 9

6. Data coming. . . - Sea State CCI v 0 : extension of Globwave data + extra variable with EMD-filtered Hs - Sea State CCI v 1 : early 2020 ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 10

7. Need for ECMWF reanalysis - We need winds, waves, sea ice – Waves are biased : re-run with other parameterizations & other wave models (1 st order vs 3 rd order scheme …) (Bidlot et al. work in progress, Ardhuin et al. , work in progress) – Winds are biased (at high winds) … so also use CFSRR … → Future data assimilation systems (phase 2 ? ) → Future parameterizations for ECMWF model - We would love to have currents … not very good yet → SKIM for EE 9 ! ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 11

8. CMUG & CRG complementarity - How will you know if your CRG work is complementary with CMUG research? ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 12

9. Planned meetings - ISSI Meeting on Coastal Sea Level (done) → 4 related papers in ASR - annual COWCLIP meetings (JCOMM-related group on wave climate) - 2019 AGU Fall Meeting → wave & current session co-convened - EGU - Living Planet Symposium → sea state + CCI sessions - Ocean. Obs'19 → 4 related papers in Frontiers in Mar. Sci. - Waves Hindcasting & Forecasting Conference (Melbourne) - OMAE -. . . ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 13

9. Backup slides Sampling is critical for extremes Wave data can be used in several ways : - identifying and correcting wave model biases (e. g. Ardhuin et al. 2010) - assimilating into reanalyses (e. g. ERA 5) Gridded daily maps are at best useless, at worst misleading. ESA UNCLASSIFIED - For Official Use ESA | Sea. State CCI at CMUG, 30/10/2018 | Slide 14