1. Z.-C. Guo P. Dirmeyer X. Gao M. Zhao __________________________________ The 84th AMS Annual Meeting, Seattle, WA, Jan. 13, 2004 Evaluation of temporal variability in modeled global soil wetness

2. Acknowledgements This work is supported by the NASA grant awarded to Dr. Paul Dirmeyer Special thanks are given to all the GSWP 2 participants

3. Outline Evaluation of temporal variability in modeled soil wetness is important. (application of soil wetness products; LSS development) Global soil wetness products and evaluation datasets Time scale of the variability in modeled soil wetness Evaluation of interannual variability and seasonal cycle in modeled soil wetness Can we find ENSO signals in modeled soil wetness?

4. Global soil wetness products and evaluation datasets Global soil wetness products: –ERA40Willmott & Matsuura –NCEP DOE IIGOLD T63 –NCEP/NCARNCEP/CPC –Global soil wetness products Observation datasets: –Global Soil Moisture Data Bank

6. SSiB

7. ERA40

15. Summary To some extents, models agree on the spatial pattern of time scale of soil wetness variability. Dry areas show much longer time scale. In the midrange of soil wetness, the time scale tends to decrease as the wetness increases. Near the upper and lower limits, the time scale behaviors are model-dependent. In comparison with observations, most models have good performances in simulating interannual variability and seasonal cycle of soil wetness. Certain ENSO signals can be found in modeled soil wetness although correlations between SOI and modeled soil wetness are marginal to the Student T-test.

18. NCEP DOE II