1 / 20

Update on winds derived from MODIS

Update on winds derived from MODIS. Lars Peter Riishojgaard, John Wu, Meta Sienkiewicz Global Modeling and Assimilation Office. Overview. Context of current study Data assimilation system Results Discussion. MODIS winds now and in the future.

nuala
Download Presentation

Update on winds derived from MODIS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Update on winds derived from MODIS Lars Peter Riishojgaard, John Wu, Meta Sienkiewicz Global Modeling and Assimilation Office

  2. Overview • Context of current study • Data assimilation system • Results • Discussion Lidar Working Group, Miami, February 6-9 2007

  3. MODIS winds now and in the future • Good results obtained by many centers with assimilating polar winds from MODIS • Used operationally in all major global forecast systems • No current plans for what comes after MODIS (2008+) • Polar winds is not an NPOESS EDR • No water vapor channel on VIIRS • Unlikely to happen before 2020 • No water vapor channel on METOP/AVHRR • Unlikely to happen before 2017/18 • Limited coverage from LEO • Real-time delivery of multi-temporal imagery products from LEO is difficult/expensive • MODIS winds generally arrive 4-6 hours after real time when using bent pipe Lidar Working Group, Miami, February 6-9 2007

  4. Community activities • Broad scientific and operational interest in high-latitudfe winds and other multitemporal imagery applications • Operational NWP community voicing strong support • WMO recommendation to the space agencies to pursue high-latitude water vapor winds with timely delivery in the post-MODIS era (WMO CBS ET/ODDRGOS) • NESDIS/JPL study of imaging MEO constellation targeting polar winds • NOAA/NESDIS has repeatedly stated interest in and support for the Molniya Orbit Imager mission proposal developed by Goddard • CSA launching pre-Phase A study of a Molniya-like communications system • ESA may start pre-Phase A study of a Molniya imaging mission within the next year funded by Finland, Canada, Germany and Denmark • Russian consortium led by Roshydromet preparing a Molniya orbit imaging proposal (GEOSS context?) Lidar Working Group, Miami, February 6-9 2007

  5. Building the case for a MODIS winds follow-on • NESDIS and GSFC collaborating on economic assessment of polar winds impact • “Orbit neutral” assessment of the expected economic impact of having feature tracking winds (cloud and water vapor) available over entire NH • G. Dittberner, L. P. Riishojgaard, Mitretek • Since both Molniya and MEO will provide increased coverage over what is possible from LEO, the MODIS winds results can be used to obtain a lower bound on the expected impact • Hurricane track forecasting (NCEP/JCSDA diagnostics) • Low-level temperature over the lower 48 (this study) • Jet-stream forecasts (this study) Lidar Working Group, Miami, February 6-9 2007

  6. Upper air mass observations (AMSU; 6 hours)

  7. Lidar Working Group, Miami, February 6-9 2007

  8. GWOS Coverage • Around 600 radiosonde stations (black) provide data every 12 h • GWOS (blue) would provide ~3200 profiles per day

  9. Molniya OSSE (Observing system simulation experiment) GEOS-4; Atlas et al. 6-hour winds coverage, 4 LEO’s  Apogee winds coverage, Molniya  Forecast improvement over North America, 48 cases 

  10. 2004 ATLANTIC BASIN AVERAGE HURRICANE TRACK ERRORS (NM) table courtesy of Le Marshall et al.; results compiled by Qing Fu Liu.

  11. Assimilation system • GEOS-5 • Finite volume model developed by DAO/GMAO • GSI analysis developed jointly with NCEP/EMC • Pre-operational version (GEOS-5 tag beta10p4) • Forecast error covariance statistics still subject to tuning Lidar Working Group, Miami, February 6-9 2007

  12. Experiments • Jan/Feb 2006 (30 forecast cases) • All NESDIS MODIS winds included • Horizontal resolution 1 by 1 ¼ degrees • Verification carried out against self and NCEP operational analysis Lidar Working Group, Miami, February 6-9 2007

  13. Lidar Working Group, Miami, February 6-9 2007

  14. Lidar Working Group, Miami, February 6-9 2007

  15. Lidar Working Group, Miami, February 6-9 2007

  16. Lidar Working Group, Miami, February 6-9 2007

  17. Lidar Working Group, Miami, February 6-9 2007

  18. Discussion • MODIS winds add skill in all regions and for all variables • Consistently 15-20% reduction in North Atlantic tropical cyclone track error throughout the forecast range • A few hours of added skill in the 500 hPa height field at the five day forecast range • Roughly a 10% reduction in the RMS error of the zonal wind component at flight levels in the North Atlantic corridor • Small but positive contribution to the low-level CONUS temperature forecast Lidar Working Group, Miami, February 6-9 2007

  19. Discussion (II) • Remarkable contribution in spite of • Sparse coverage (no overlap with GEO) • Infrequent imaging (~100 minute repeat rate) • Difficult viewing geometry • No direct influence on the forecast initial conditions in the tropical cyclone study • Relatively few MODIS wind vectors meet the NCEP operational data cut-off Lidar Working Group, Miami, February 6-9 2007

  20. Future plans • Further improvement in data selection and quality control • More data analyzed • EE (John Le Marshall) • Additional diagnostics • Test different seasons, different periods • Results to be forwarded to NESDIS/Mitretek for inclusion in economic impact assessment report Lidar Working Group, Miami, February 6-9 2007

More Related