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Regional Applications of the NCEP Coupled Forecast System (CFS)

Regional Applications of the NCEP Coupled Forecast System (CFS). Dr. Wassila M. Thiaw Team Lead African and International Desks Climate Prediction Center National Centers for Environmental Predictions National Oceanic and Atmospheric Administration. Acknowledgments.

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Regional Applications of the NCEP Coupled Forecast System (CFS)

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  1. Regional Applications of the NCEP Coupled Forecast System (CFS) Dr. Wassila M. Thiaw Team Lead African and International Desks Climate Prediction Center National Centers for Environmental Predictions National Oceanic and Atmospheric Administration DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  2. Acknowledgments • Vadlamani Kumar and Nick Novella, CPC International Team • EMC Ocean Modeling Team, Dave Behringer, Lead • CPC Ocean Monitoring Team, Yan Xue, Lead • NCEP CFS Team, Suranjana Saha and Hua Lu Pan DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  3. Climate Prediction Center Mission National temperature and precipitation outlooks, but not monthly / seasonal rankings Focus: weeks, months, seasons, years (i.e. short term climate) Forecasts in collaboration with other NCEP Centers, NOAA line offices, other agencies and labs Integral to NWS Seamless Suite of Products We deliver climate prediction, monitoring, and assessment products for timescales from weeks to years to the Nation and the global community for the protection of life and property and the enhancement of the economy. Temperature Outlook DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  4. Climate Prediction CenterInternational DesksAfrican Desk, International Projects Training Coverage • Support capacity building in weather and climate in developing countries: Africa, central America, and Asia • Provide access to NCEP global data and products to domestic and international agencies and to the public New Website Africa Hazards Week1 Precipitation Probability of exceedance Global TC monitoring DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  5. Deliver climate information and services Transfer technology to National Meteorological and Hydrological Services and regional institutions Build network of well-trained international scientists Provide data to support NCEP’s mission CPC International Desks DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  6. Outline • NCEP Climate Forecast System (CFS) • CPC Prediction and Monitoring Tools • CFS Reanalysis and Reforecast Project • Climate Dynamics of southern and eastern Africa DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  7. The NCEP CFS ComponentsCFS Operational Implementation : 24 Aug 2004 • T62/64-layer version of the 2003 operational NCEP atmospheric GFS (Global Forecast System) model • GFDL MOM-3 (Modular Ocean Model, version 3) • 40 levels • 1 degree resolution, 1/3 degree on equator • Reference: Saha et al. (2006), Journal of Climate, 19, 3483-3517. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  8. Data AssimilationSystems • Atmosphere (Global Data Assimilation System – GDAS) • Ocean (Global Ocean Data Assimilation System – GODAS). • Models incorporate observations in a dynamically consistent fashion to produce analyses of initial conditions, which provide starting point for making predictions of future conditions. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  9. Skill in SST Anomaly Predictions Predictions archived since 1997. The CFS shows a substantial increase in skill over the previous NCEP operational forecast model (CMP14) and comparable skill to operational statistical forecast models (CCA, CA, CONS, and MARKOV). DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  10. SST Biases for DJF and JAS DJF Climatology JAS Climatology Lead0 - Obs Lead3 - Obs Lead6 - Obs DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  11. SST Biases for DJF and JAS DJF JAS Lead0 - Obs Lead3 - Obs Lead6 - Obs DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  12. Skill for Raw and Bias-corrected Niño 3.4 SST Predictions Bias correction improves the skill for all prediction methods (compare bottom panels with top panels). DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  13. Precipitation Biases for DJF and JAS DJF Climo JAS Climo Lead0 - Obs Lead3 - Obs Lead6 - Obs DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  14. OBS DJF Clim. 1981-2004 CFS DJF Clim. 1981-2004 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  15. Atmospheric Circulation CFS Wind Clim. 1981-2004 CDAS Wind Clim. 1981-2004 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  16. CFS_2-tier DJF Precipitation Climatology 1981-2004 OBS CFS DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  17. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  18. Precipitation Interannual Variability RFE Oct 1 2006 – May 31 2007 RFE Oct 1 2005 – May 31 2006 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  19. Time – Latitude 5-day RFE 30-40E 2005-06 2006-07 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  20. Time – Latitude 5-day CFS 30-40E 2005-06 2006-07 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  21. Time – Latitude 5-day P Difference 30-40E RFE 2006-07 minus 2005-06 RFE 2006-07 minus 2005-06 3 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  22. Central Africa Seasonal Rainfall Predictability DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  23. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  24. Summary of CFS Version 2004 • CFS skill in predicting Niño 3.4 SST anomalies is greater than the previous NCEP operational 2-tier model (CMP14), and comparable to NCEP operational statistical models. • For southern Africa, precipitation biases appear to be related to errors in low level wind fields and atmospheric convection. Nonetheless, there is some predictability in the system for the austral summer. • Seasonal rainfall predictability can be significantly enhanced in the areas where the ENSO signal is strong such as portions of central Africa and eastern Africa by downscaling CFS forecasts. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  25. CFS SST ForecastsMarch 2010 initial conditions The CFS ensemble mean (heavy blue line) predicts neutral conditions to return by late spring-early summer followed by a development of La Nina that is expected to last through fall 2010. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  26. IRI Forecasts for Niño 3.4 (March 2010) Most models suggest a gradual return to ENSO-neutral conditions by May-July 2010, which persist into the fall. Some models suggest the potential of continued El Niño conditions or the development of La Niña conditions during the late summer or fall. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  27. Prediction, Assessment, and Monitoring of the climate system at CPC Global and Regional Climate Analysis (R1, R2, NARR, CFSR) Real-time Global Climate Predictions and Monitoring Forecast Tool Development/ Improvement Verifications and Expert Assessments Climate Diagnostics and Attribution Applied Research Outreach and Service International Activities 27 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  28. Predictions and Monitoring of the Global Ocean Weekly and monthly briefings State of Global Oceans Variations in tropical eastern Pacific--El Niño & La Niña Global Climate Impacts of Sea Surface Temperatures 28 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  29. Global SST Anomaly (0C) and Anomaly Tendency • El Nino condition (NINO 3.4 > 0.5oC) weakened slightly in the tropical Pacific; • PDO was in positive phase (slide 19); • SST was above-normal in the tropical Indian Ocean and tropical North and South Atlantic; • Large SST anomalies in the subtropical South Pacific, and North Atlantic • SST decreased slightly in the eastern tropical Pacific; • SST tendency was large in the Southern Ocean • SST increased in tropical North and South Atlantic. • SST tendency was small in the Indian Ocean Fig. G1. Sea surface temperature anomalies (top) and anomaly tendency (bottom). Data are derived from the NCEP OI SST analysis, and anomalies are departures from the 1971-2000 base period means. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  30. Evolution of Indian Ocean SST Indices Fig. I1a. Indian Ocean Dipole region indices, calculated as the area-averaged monthly mean sea surface temperature anomalies (OC) for the SETIO [90ºE-110ºE, 10ºS-0] and WTIO [50ºE-70ºE, 10ºS-10ºN] regions, and Dipole Mode Index, defined as differences between WTIO and SETIO. Data are derived from the NCEP OI SST analysis, and anomalies are departures from the 1971-2000 base period means. • Positive eastern (SETIO) pole SSTA persisted in Mar 2010. • Both eastern (SETIO) and western (WTIO) pole SST have been persistently above-normal since April 09. • DMI became above-normal in Mar 2010. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  31. Tropical Indian: SST Anom., SST Anom. Tend., OLR, Sfc Rad, Sfc Flx, 925-mb & 200-mb Wind Anom. • SSTA exceeding +1C presented in the tropical Indian Ocean. • Net surface heat flux anomalies contributed to the positive (negative) SSTA tendency in the North (South) Indian Ocean. • Convection was suppressed over the Maritime Continent, and intensified in southeastern Indian Ocean • Consistent with the suppressed convection was low-level divergence (up-level convergence) wind anomalies in the Maritime Continent Fig. I2. Sea surface temperature (SST) anomalies (top-left), anomaly tendency (top-right), Outgoing Long-wave Radiation (OLR) anomalies (middle-left), sum of net surface short- and long-wave radiation, latent and sensible heat flux anomalies (middle-right), 925-mb wind anomaly vector and its amplitude (bottom-left), 200-mb wind anomaly vector and its amplitude (bottom-right). SST are derived from the NCEP OI SST analysis, OLR from the NOAA 18 AVHRR IR window channel measurements by NESDIS, winds and surface radiation and heat fluxes from the NCEP CDAS. Anomalies are departures from the 1979-1995 base period means except SST anomalies are computed with respect to the 1971-2000 base period means. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  32. CFS DMI SST Predictions from Different Initial Months DMI = WTIO- SETIO SETIO = SST anomaly in [90oE-110oE, 10oS-0] WTIO = SST anomaly in [50oE-70oE, 10oS-10oN] • Latest forecasts called for weak positive Indian Ocean Dipole (IOD) in fall 2010. Fig. M2. CFS Dipole Model Index (DMI) SST predictions from the latest 9 initial months. Displayed are 40 forecast members (brown) made four times per day initialized from the last 10 days of the initial month (labelled as IC=MonthYear) as well as ensemble mean (blue) and observations (black). The hindcast climatology for 1981-2006 was removed, and replaced by corresponding observation climatology for the same period. Anomalies were computed with respect to the 1971-2000 base period means. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  33. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  34. IESA – Integrated Earth System Analysis DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  35. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  36. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  37. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  38. Climate Forecast System V1 vs. V2 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  39. Forcing: Wind Stress Heat Flux New Global Ocean Data Assimilation System Ocean Model MOMv4 (GFDL) 1/2o x 1/2o z-coord, 40 levels Data: T(z)&S(z) SST SSH First Guess Analysis Data Assimilation 3DVariational Cost Function: J = ½ (x-xb)TB-1(x-xb) + ½ (y-H(x))TR-1(y-H(x)) Model Data DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  40. NEW GODAS • Based on MOMv4, the new GODAS has a resolution of 1/2o x 1/2o (1/4o in the tropics). It uses a z-coordinate in the vertical and has 40 levels. The domain is global and includes an ice model. • GODAS has a 3D variational assimilation scheme. • Assimilation data are temperature profiles (XBT, Argo, TAO, TRITON, PIRATA, RAMA), salinity profiles (Argo, synthetic profiles derived from a seasonal T-S relation), TOPEX/Jason-1 Altimetry and SST (Reynolds’ daily 1/4o SST). • GODAS can be forced by surface flux products (wind stress, heat flux components) in “stand alone” mode or be coupled to an atmospheric model. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  41. 6hr Atmospheric Model GFS (2007) T382 64 levels GDAS GSI 24hr 6hr Land Model Ice Mdl SIS LDAS Ice Ext Ocean Model MOMv4 fully global 1/2ox1/2o (1/4o in tropics) 40 levels 6hr GODAS 3DVAR New CFS at NCEP Climate Forecast System DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  42. MOMv4 based GODAS 1/2o resolution Global GODAS has eastward flow on equator in Indian Ocean MOMv3 based GODAS 1o resolution Quasi-global Drifters show stronger flow in western Boundary and Southern Ocean AOML surface drifter based climatology Independent Lumpkin et al. GODAS compared with independent surface drifter velocities The agreement is very good given that GODAS does not directly assimilate velocity observations and the drifter velocities are derived from the lagrangian motion of the drifters. DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  43. GODAS compared with surface drifter velocities MOMv4 based GODAS 1/2o resolution Global MOMv3 based GODAS 1o resolution Quasi-global AOML surface drifter based SST climatology Independent data (Lumpkin et al.) DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  44. CFSR CFSR SSH has a higher correlation with Altimetry SSH than GODAS SSH in the tropical Indian Ocean and extratropical Oceans, but CFSR has a lower correlation in the tropical Atlantic, which is probably associated with drifts in subsurface temperature and salinity and erroneous overturning circulation cells in the tropics (see next slide). GODAS CFSR - GODAS 44 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  45. Climate Dynamics of Eastern and Southern Africa • Present the basic atmospheric features of southern and eastern Africa climate • Place the climate dynamics of the region in a global context as seen from NCEP reanalysis-1 • See if the NCEP CFS Reanalysis (CFSR) is able to capture the atmospheric features DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  46. Climate Dynamics of Eastern and Southern Africa Northern and southern hemisphere seasons DJF, austral summer JAS, boreal summer Emphasis on the large-scale flow and precipitation fields DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  47. Atmospheric Circulation Atlantic-Indian Ocean Basin Low level, 850 hPa geopotential heights, DJF 1979-2008 Subtropical highs DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  48. Atmospheric Circulation Atlantic-Indian Ocean Basin Low level, 850 hPa geopotential heights, DJF 1979-2008 Thermal lows DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  49. Low level, 850 hPa geop. heights & winds, DJF 1979-2008 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

  50. Low level, 850 hPa geop. heights & winds, DJF 1979-2008 CFSR RA-1 DBCP Capacity Building workshop for the Western Indian Ocean, Cape town, 19-23 April 2010

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