Rossana Dragani

1. Using and evaluating PROMOTE services at ECMWF Rossana Dragani PROMOTE User Meeting Nice, 16 March 2009

2. Overview of ECMWF • ECMWF is an independent international organization that provides medium and extended-range weather forecasts as well as state-of-the-art super-computing facilities for scientific research. • ECMWF is currently supported by 31 member states, mainly across Europe. • The ECMWF system is a global spectral model with a horizontal truncation resolution of T799 (~ 25 km), and 91 vertical levels from the surface up to 0.01 hPa. The assimilation is performed with a Four-Dimensional Variational (4D-Var) data assimilation scheme. • The ECMWF analyses and forecasts are widely used for a number of activities and studies. They are • used in house to study the dynamical and chemical evolution of the Earth-system, • routinely distributed to the ECMWF Member States. • In addition, the ECMWF model forecasts and analyses are routinely used to monitor observations from a number of satellites. In some cases, the ECMWF forecasts are also used as a priori information to constrain retrieval procedures of satellite instruments (e.g. ESA’s ERS2, ENVISAT).

3. ECMWF involvement in GMES projects • ECMWF is involved in various GMES projects. • PROMOTE: • ECMWF has been receiving the PROMOTE NRT total column ozone retrieved from the SCIAMACHY instrument (on board ENVISAT) since February 2004. • These data have been assimilated in the ECMWF operational NWP since September 2004. • The Global and regional Earth-system Monitoring using Satellite and in-situ data (GEMS): • GEMS is developing comprehensive monitoring and forecasting systems for trace atmospheric constituents important for climate and air quality. • GEMS started in 2005 and will run until mid 2009.

4. Evaluation of PROMOTE services • Evaluation of the PROMOTE data quality: • Impact on the ECMWF ozone analyses performed before the operational use of the PROMOTE data • Continuous monitoring of the PROMOTE products www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/ • Evaluation of the PROMOTE service: • Timeliness: Customers want forecasts early, therefore NWP requires data early.

5. Evaluation of PROMOTE services • Evaluation of the PROMOTE data quality: • Impact on the ECMWF ozone analyses performed before the operational use of the PROMOTE data • Continuous monitoring of the PROMOTE products www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/ • Evaluation of the PROMOTE service: • Timeliness: Customers want forecasts early, therefore NWP requires data early.

6. Motivations for using PROMOTE data at ECMWF • The assimilation of PROMOTE TCO was seen to improve the ECMWF ozone analyses and forecasts in particular the representation of the Antarctic ozone hole. • ECMWF started the active assimilation of the PROMOTE TCO in the operational suite in September 2004. • Two pairs of assimilation experiments were run to test the impact of the PROMOTE data on the ECMWF ozone analyses: • Period 1: 24 April - 23 May 2004 • Period 2: 1 August - 28 September 2004 (e-suite) • CTRL:operational setup (NOAA-16 SBUV/2 ozone layers) • PERT: CTRL + PROMOTE TCO

7. Fit to NOAA-16 SBUV PCO (Apr-May 2004): CTRL PERT Obs-ana=-10.5 DU Stdv=14.7 DU Obs-ana=3.2 DU Stdv=14.7 DU Ozone layer: 16 hPa - surface

8. Impact of the PROMOTE SCIA TCO on the ECMWF ozone analyses (Apr-May 2004) CTRL PERT TOMS

9. Fit to ozone sondes (Apr-May 2004): Sonde CTRLPERT

10. Neumayer (lat=-71, lon=-8) Sonde E-suite O-suite Impact of the PROMOTE SCIA TCO on the ECMWF ozone analyses (Aug-Sep 2004) O-suite (25R2) E-suite (25R3) TOMS

11. Evaluation of PROMOTE services • Evaluation of the PROMOTE data quality: • Impact on the ECMWF ozone analyses performed before the operational use of the PROMOTE data • Continuous monitoring of the PROMOTE products www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/ • Evaluation of the PROMOTE service: • Timeliness: Customers want forecasts early, therefore NWP requires data early.

12. OBS DEP STD DEV 2008 2007 FG AN OBS PROMOTE TCO monitoring statistics:time series (2007-2008) • The quality of PROMOTE SCIA TCO has been stable during the years. • FG- and An- departures are about 2DU on global average. www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/

13. Comparison between PROMOTE SCIA and OMI TCO: SCIAMACHY OMI 2008

14. Evaluation of PROMOTE services • Evaluation of the PROMOTE data quality: • Impact on the ECMWF ozone analyses performed before the operational use of the PROMOTE data • Continuous monitoring of the PROMOTE products www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/ • Evaluation of the PROMOTE service: • Timeliness: Customers want forecasts early, therefore NWP requires data early.

15. Operability of data products to ECMWF: • Two 12-hour (from -3h to +9h) analysis and forecast cycles at 00 and 12 UTC • Two 6-hour (from -3h to +3h) analysis and forecast cycles at 00 and 12 UTC Delayed cut-off Early delivery

16. Operability of PROMOTE data to ECMWF (DCDA) 2006 2007 2008

17. Conclusions and remarks: • Assimilation of PROMOTE SCIA TCO improved fit of ECMWF ozone column and profiles to independent data, and started operationally in Sept 2004. • The quality of TOSOMI TCO has been stable during the years. • FG- and An- departures are about 2DU on global average. • PROMOTE SCIA TCO is in very good agreement with OMI TCO (independent observations) at mid and high latitudes. • Smaller TCO values can be found in the TOSOMI product compared with OMI in the Tropics. • Slightly higher in the Antarctic polar vortex during spring. • The timeliness over the last three years (2006-2008) has been good, and the operability of the PROMOTE data to ECMWF higher than 80%. • However, a drop of about 8% (annual mean) was found in the operability of these data over the last three years.