Future Satellite Programmes and the Relevance of NWP Impact Studies

1. Relevance of NWP Impact Studies for Future Satellite Programmes J. Schmetz, R. Stuhlmann, P. Schlüssel and D. Klaes EUMETSAT

2. Content • Informed decisions on future operational meteorological satellites and related services must be based on careful analyses • Important is: i) continuity and robustness of services and ii) evolution of services based on new requirements • Recall that optimum use of (satellite) observations (for NWP) requires learning how to use the data • An established way to demonstrate usefulness is through impact studies with an NWP system • This presentation takes examples from the future EUMETSAT Programmes Meteosat Third Generation (MTG) and Post-EPS (EUMETSAT Polar System) to develop suggestions for an improved support by NWP to future satellite planning and development

3. Reasons behind improvements in NWP due to satellite data (from Uccellini, 2007) • Improvement is due to a balance among: • Observations • Data Assimilation & Model technology • Computing resources • Estimated 30 - 40% of improvement from observations (principally global LEO satellite data) and 60 - 70% from data assimilation and modeling techniques and computing resources • => This suggests that R&D for advanced utilisation of future missions should commence early , i.e. well before launch. This activity should be clearly separated from the development of an operational ground segment

4. Pre-launch investment in research on utilisation will increase the return on investment Utilisation of data (or return on Investment) 100% End of Satellite Life Ideal learning curve Actual learning curve Satellite Lifetime Operational readiness (should be shortly after launch)

5. Recalling the status of EUMETSAT future programmes: • - Meteosat Third Generation (MTG) • - Post-EPS (Metop next) • => The question here is: How can we help those two satellite programme developments or future programme development in general?

6. 1. Overall Phase A Status PCR PCR PRR PRR ESA C-MIN 2008 Approval full Programme Go-ahead for Phase B ESA roadmap Start Phase C/D Phase B Phase A 2009 2010 2011 2012 2013 2007 2008 EUMETSAT roadmap Phase A Preparatory Programme Council Full Programme Approval 2007 2009 2010 2011 2012 2013 2008 Council Approved the MTG PP

7. MTG will provide continuity of EUMETSAT Services 2015 2002 1977 MTG MOP/MTP MSG • 1observation mission: • MVIRI: 3 channels • Spinningsatellite • 800 kg • 2 observation missions: • SEVIRI: 12 channels • GERB • Spinning satellite • Class 2-ton • 4 observation missions: • Combined Imager: 16 channels • Infra-Red Sounder • Lightning Imager • 3-axis stabilised satellites • - Twin Sat configuration • 2,5 and 2,2 t Implementation of the EUMETSAT Mandate for the Geostationary Programme ... 30 years of continuous operations achieved ... Atmospheric Chemistry Mission (UVS) coordinated with ESA for implementation via GMES Sentinel 4/5

8. MTG IR Sounding Mission Coverage Repeat cycle Full Disk Coverage 18ox18o 60 min Local Area Cov. 18ox6o 10 min Mission Frequency range Main Contribution Band -1 cm IRS-1 700 770 CO2 IRS-2 770 980 Surface, Clouds IRS-3 980 1070 O3 IRS-4 1070 1210 Surface, Clouds IRS-6 1600 2000 H2O, IRS-7 2000 2175 CO, 1800 channels Spec.res. 0,62 1/cm

9. MTG IR Sounding Mission Coverage Repeat cycle Full Disk Coverage 18ox18o 30 min Local Area Cov. 18ox6o 10 min • Priorities IRS Mission • Atmospheric dynamic variables with high vertical resolution (e.g. water vapour flux, wind profile, transport of pollutant gases) • More frequent information on Temperature and Humidity profiles for NWP (regional and global) • Monitoring of instability / early warning of convective intensity • Cloud microphysical structure • support chemical weather and air quality applications Hyperspectral IR sounding with focus on time evolution of vertically resolved water vapour structures

10. Greatly Improved Atmospheric Motion Vectors with hyperspectral sounder (Figure courtesy of C. Velden) High-spectral Current GOES

11. Salient points from: Benefits expected from the infra-red sounder (IRS) on Meteosat Third Generation • Report to EUMETSAT Council by a working group: J. Eyre, V. Casse, S. English and J. Pailleux • MTG-IRS is an infra-red sounder of high spectral resolution which will provide information on atmospheric temperature, humidity and wind at high horizontal, vertical and temporal resolution • MTG-IRS data will contribute both through assimilation into convective-scale, regional and global NWP models and through nowcasting products. They will be particularly important for observing the advection and convergence of low-level moisture associated with some types of severe weather in Europe

12. Slides from MTG OSSE study by H. Huang et al. Xiang-Yu Huang, Hongli Wang, Yongsheng Chen National Center for Atmospheric Research, Boulder, Colorado, U.S.A. Xin Zhang University of Hawaii, Honolulu. Hawaii, U.S.A. Stephen A. Tjemkes, Rolf Stuhlmann EUMETSAT, Darmstadt, Germany MTG-IRS: An Observing System Simulation Experiment (OSSE) on regional scales

13. Slides from MTG OSSE study by H. Huang et al.Background: IRS sounding Mission on MTG will provide high-resolution data which includes temperature and water vapor information. Realistic mesoscale details in moisture are important for forecasting convective events (e.g., Koch et al. 1997; Parsons et al. 2000; Weckwerth 2000, 2004). Objective: To document the added value of water vapor observations derived from a hyperspectral infrared sounding instrument on a geostationary satellite for regional forecasting.

14. Slides from MTG OSSE study by H. Huang et al.Case A: 11 June Case observed 6-h rainfall simulated 6-h rainfall 0600 UTC 12 Jun 0600 UTC 12 Jun The observation is on Polar Stereographic Projection Grid. The simulated rainfall is on Lambert Projection Grid. The color scales are different.

15. Slides from MTG OSSE study by H. Huang et al. Summary Three storms are well reproduced in the 5 day nature run. The calibration experiment shows that the real and simulated observations have the similar impacts on the analyses increments and forecasts differences. The forecast skill is improved when MTG-IRS T and q retrieved profiles are assimilated. Added comment => Demonstration of impact of novel satellite observing system is very important work; concerted action within (to be) established framework is beneficial

16. 1. Post-EPS Status & Roadmap 2007 2008 2009 2014 2011 2012 2010 2015 2016 2017 2018 2019 2013 2020 Long Term Roadmap Operations Phase 0 Phase A Phase B Phase C/D Other Missions IR and MW Sounding VIS/IR Imaging Missions Prep. Programme Development and Operation Programme EUMETSAT Approval Processes ESA Programme ESA Ministerial Conf. go ahead for phase B/C/D

17. Post-EPS Candidate Missions Note: Rank value 3: highest priority

18. Study by ECMWF on ‘Observing System Experiments for the evaluation of degraded EPS/Post-EPS instrument scenarios (1) • Purpose of study is assessment of detrimental impact of loss Metop instruments on NWP skill • Performed by ECMWF with operational model and 4-d variational data assimilation • Study is ongoing • Some preliminary main results for forecast verification for summer 2007: • combined effect of withdrawing all Metop instruments is much larger than impact from withdrawal of individual instruments or all conventional sounders (AMSU-A, MHS and HIRS), • 12 – 24 hour tropical humidity scores are negatively affected, after 24 hrs a small positive impact at higher latitudes; this is presumably due to added variability from additional observations

19. Study by ECMWF on ‘Observing System Experiments for the evaluation of degraded EPS/Post-EPS instrument scenarios (2) • Conclusion on data withdrawal studies: • they are useful to substantiate a priority ranking for future satellite missions • they are useful to evaluate the robustness of the operational satellite observing system

20. Thought on an operational deployment scenario: ‘Near’ simultaneous observations from polar orbit by trains of satellites • 4-D Var assimilation makes need for distribution of observations over time less critical ... • Process studies and research benefits from near simultaneous observations of many parameters => this will advance NWP model physics • => Trains of satellites might be an option for operational and research missions … serves operational (NWP) requirements and fosters research on physics? • Requires detailed studies • Could be topic for CGMS and CEOS

21. Meteosat-8 monitors deep convective clouds Area over central Africa Red pixels: T6.2 > T10.8 How can this be explained? => cloud tops overshooting into lower stratosphere - confirmed by “Cloudsat”observations

22. Cloudsat explains physics in areas with T6.2 > T10.8(from Cloudsat website and adapted by Chung et al., 2007)

23. Conclusions and Suggestions (1) • OSEs are a good tool to provide guidance on priorities of future missions and to demonstrate the robustness of the GOS • WMO should establish a process that guides activities to demonstrate the impact of new satellite missions (e.g. guidance on best practice … as well as coordination of such activities as part of future planning of a ‘Joint space-based observing systems’); • A WMO concerted effort on performing OSSEs in support of future satellite missions .… this is ongoing • => Benefits: Will be an additional element in support of the planning and coordination of a future GOS from outset. It could also increase the incentive to perform satellite/instrument development in a joint and cost-effective manner.

24. Conclusions and Suggestions (2) • Work toward the ‘full exploitation’ of new elements of a satellite observing system should be part of satellite programme development, i.e. the development of ‘new science’ for the full utilisation of a satellite mission should be part of a satellite development (this ought to be different from the development of the operational ground segment) • => Benefit: Optimum use is reached quicker, resulting in higher return on investment • Further issues and questions: • To what extent is it useful to fly future polar research and operational satellite missions as ‘trains’? This would help understanding processes and advance model physics. • Is guidance needed on choices between diversity of polar observations and better temporal coverage with similar/same observation (or how many of a kind is enough)?