On the first day of the meeting (13 April 1999), a joint session of the Natural Variability Working Group (NVWG), Seasonal-to-Interannual Working Group (SIWG), and Atmosphere Model Working Group (AMWG) was held to hear presentations. On the second day (14 April 1999), the NVWG and SIWG met jointly to hear additional presentations and for discussion. The meeting concluded with a joint discussion attended by the AMWG, NVWG, and SIWG members.

Presentations on 13 April 1999 (NVWG/SIWG/AMWG) on CSM/CCM3:

1. Diagnosis of model performance and proposal of extended diagnostics (Sumant Nigam, University of Maryland)

2. Analysis of upper tropospheric humidity (Bill Collins, NCAR)

3. Intraseasonal variability and convection schemes (Eric Maloney, University of Washington)

4. Tracer diagnostic of convective transport (Victor Dvortsov et a., NOAA)

5. Variability of South Asian Monsoon (Jerry Meehl, NCAR)

6. Variability in the PNA region (J. Shukla, COLA)

7. PNA and tropical SST (Hui Wang and Rong Fu, University of Arizona.)

8. NAO and Zonal Index (Eric DeWeaver and Sumant Nigam, University of Maryland)

9. Upper ocean model for short-term climate variability (Gokhan Danabasoglu, NCAR)

10. Improving simulation of ENSO and tropical annual cycle (Ed Schneider, COLA)

11. Circulation diagnostics (Jim Boyle, Lawrence Livermore National Laboratory)

12. Seasonal-to-interannual coupled model (Joe Tribbia, NCAR)

13. Simulation of high frequency variability (Lucrezia Ricciarduli, NCAR)

14. El Nino in the PCM and CSM (Jerry Meehl and Julie Arblaster, NCAR)

15. New Paleo-CSM (Bette Otto-Bliesner, NCAR)

16. ENSO diagnostics (Chul Chung and Sumant Nigam, University of Maryland)

17. Circulation regimes (Andy Robertson, UCLA)

18. Intermediate tropical atmospheric model (David Neelin and Ning Zeng, UCLA)

19. 21st century climates over the U.S. (Aiguo Dai, NCAR)

Presentations on 14 April 1999 (NVWG/SIWG):

1. Tropical Atlantic variability (R. Saravanan, NCAR)

2. Comparing nature and CCM3s response to El Nino (Grant Branstator, NCAR)

Discussion:

1. Strategy for improving deficiencies of CSM related to simulation of seasonal-to-interannual variability was discussed. Deficiencies of the annual mean and annual cycle in low latitudes can be attributed to the atmosphere. There has been a significant amount of work done examining the role of the convection parameterization in causing these deficiencies. Problems in high-frequency variability of tropical convection and weak extratropical ENSO response were identified, but work on correcting these problems is only in the beginning stages.

2. OGCM intercomparison with common forcing would be useful.

3. NSF support for CSM diagnostic activities at the universities would be beneficial.

Participant List:

Michael Alexander, NOAA

Julie Arblaster, NCAR

John Bergman, NOAA/CDC

Jim Boyle, Lawrence Livermore National Laboratory

Grant Branstator, NCAR

Chul Chung, University of Maryland

Bill Collins, NCAR

Aiguo Dai, NCAR

Gokhan Danabasoglu, NCAR

Eric DeWeaver, University of Maryland

Jim Hack, NCAR

Matthew Huber, University of California, Santa Cruz

Jeff Kiehl, NCAR

JoAnn Lysne, UCAR Visiting Scientist Program

Jerry Meehl, NCAR

Matthias Munnich, UCLA

Sylvia Murphy, NCAR

Sumant Nigam, NCAR

Joel Norris, NCAR Advanced Study Program

Bette Otto-Bliesner, NCAR

David Pierce, University of California, San Diego

David Randall, Colorado State University

Marilyn Raphael, UCLA

Phil Rasch, NCAR

Lucrezia Ricciarduli, NCAR

Andy Robertson, UCLA

R. Saravanan, NCAR

Edwin Schneider, COLA

Dennis Shea, NCAR

J. Shukla, COLA

Mark Snyder, University of California, Santa Cruz

Karl Taylor, Lawrence Livermore National Laboratory

Joe Tribbia, NCAR

Hui Wang, University of Arizona

Ning Zeng, UCLA

Chidong Zhang, RSMAS, University of Miami