1. 1 Yun Fan, Huug van den Dool, Dag Lohmann, Ken Mitchell CPC/EMC/NCEP/NWS/NOAA Kunming, May, 2004

2. 2 Motivations Improve soil moisture data for CPC’s drought & flood monitoring tools Improve land surface model via data validation and model intercomparisons Provide model consistent initial conditions for various ranging forecasts Provide a long time series of realistic land surface data for land memory & predictablity studies Coupled atmosphere-land-ocean modeling Other……

4. 4 CPC Leaky Bucket Soil Moisture Model (Huang et al 1996) The soil moisture budget over an area A: Where W(t) is soil water content P(t) precipitation E(t) evaportranspiration R(t) net streamflow divergence G(t) net groundwater loss Forcing Data: -CPC daily temperature updates -CPC daily precipitation updates (Higgins & Shi) -Monthly precipitation and temperature from NCDC

5. 5 CPC Leaky Bucket Soil Moisture Model - cont Output Data Coverage: - 72 years (1931-yesterday) on 344 US climate divisions - 56+ years (1948-present) on global domain Products Web Site (daily & monthly updated): - http://www.cpc.ncep.noaa.gov/soilmst / (official site) - http://www.cpc.ncep.noaa.gov/soilmst/index.htm (test site)

6. Current CPC soil moisture related monitoring & predictive activities: – Drought & flood monitoring – Empirical forecast tools (Constructed Analog) – GFS forecast & climate prediction

8. CPC Leaky Bucket Model - Monitoring

11. CPC Leaky Bucket Model - GFS bias corrected ensemble forecasts (daily Prcp and Temp at 0Z) are used to drive the soil moisture model.

14. CPC Leaky Bucket Model CA Monthly and Seasonal Forecasts

15. 15 Retrospective LDAS Run Project A joint project to Land Data Assimilation System (LDAS) Project NOAH Land Surface Model –Physically far more complete –Higher resolution (spatial: 1/8 degree grid, temporal: hourly) Forcing Data (1948-1998): –Observed precip (Higgins & Shi) –Atmospheric forcing (From global reanalysis) Outputs Will Provide: –Improved soil moisture & associated land data variables. –Superior model consistent initial conditions –others

17. 17

20. Data validation cr=0.70 cr=0.73 cr=0.55

26. Jan &Jul Climatology (1961-1990) of all water balance components

27. Land Surface Water Budget Over Conterminous USA

28. Mon W P E R+G P-E-R-G 1 581.2 (294.2) 52.0 5.5 31.8 14.6 2 592.5 (304.0) 49.8 10.3 33.3 6.2 3 600.0 (308.8) 62.9 24.5 39.1 -0.7 4 595.6 (302.0) 59.4 42.8 30.2 -13.7 5 582.8 (289.8) 70.9 64.8 21.2 -15.1 6 564.6 (276.8) 66.2 75.7 14.2 -23.8 7 538.4 (260.1) 64.8 77.8 10.4 -23.5 8 520.1 (250.0) 62.2 67.6 9.0 -14.3 9 514.3 (248.3) 61.4 49.3 8.8 3.3 10 520.2 (253.3) 51.7 31.9 9.1 10.8 11 539.8 (266.8) 58.0 14.0 13.5 30.5 12 565.8 (282.6) 58.5 4.5 27.3 26.8 Year 559.0 (278.1) 59.8 39.1 20.7 0.0 averaged over 125W-75W, 30N-48N US monthly values of all components of land surface hydrology (mm/mon)

29. P(t) - E(t) - R(t) – G(t)

30. Simulated extreme hydrologic events: 1988 drought & 1993 flood

31. 31 Summary & Future Work Summary & Future Work Monitoring & predicting land surface variables LSMs can simulate some realistic land features Need more detailed analysis & studies –Data validation, model comparisons & improvements –Modeling & Prediction experiments Global Retrospective LDAS Run Others