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

Lidar Working Group, Miami, February Overview Context of current studyContext of current study Data assimilation systemData assimilation system ResultsResults DiscussionDiscussion

Lidar Working Group, Miami, February 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 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 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)

Goddard Space Flight Center “Use or disclosure of these data is subject to the restriction on the title page of this document” Upper air mass observations (AMSU; 6 hours)

Lidar Working Group, Miami, February

Goddard Space Flight Center “Use or disclosure of these data is subject to the restriction on the title page of this document” GWOS Coverage Around 600 radiosonde stations (black) provide data every 12 h GWOS (blue) would provide ~3200 profiles per day

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

Cntrl Cntrl + MODIS Cases (#) 00-h12-h24-h36-h48-h72-h96-h120-hTime AVERAGE HURRICANE TRACK ERRORS (NM) 2004 ATLANTIC BASIN table courtesy of Le Marshall et al.; results compiled by Qing Fu Liu.

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

Lidar Working Group, Miami, February Experiments Jan/Feb 2006 (30 forecast cases)Jan/Feb 2006 (30 forecast cases) All NESDIS MODIS winds includedAll NESDIS MODIS winds included Horizontal resolution 1 by 1 ¼ degreesHorizontal resolution 1 by 1 ¼ degrees Verification carried out against self and NCEP operational analysisVerification carried out against self and NCEP operational analysis

Lidar Working Group, Miami, February

Discussion MODIS winds add skill in all regions and for all variablesMODIS winds add skill in all regions and for all variables Consistently 15-20% reduction in North Atlantic tropical cyclone track error throughout the forecast rangeConsistently 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 rangeA 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 corridorRoughly 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 forecastSmall but positive contribution to the low-level CONUS temperature forecast

Lidar Working Group, Miami, February 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 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