Subseasonal Reforecasts and Forecasts with CESM2

CESM2(CAM6) and CESM2(WACCM6) have been used to carry out subseasonal (45-day long) reforecasts for the time period 1999 to 2020 and are being used to carry out weekly real-time forecasts. Simulations and output follow the Subseasonal Experiment (SubX) protocol. Reforecast and forecast data are freely available to the broader community. Details of the two systems and available data vary and are described below:

Subseasonal Reforecasts & Forecasts with CESM2(CAM6)

  • Reforecasts initialized every Monday between 1999 to 2020
  • 45-day simulations
  • 11-member ensemble for reforecasts
  • Atmospheric initial conditions: CFSv2
  • Land initial conditions: CLM2 spun up with CFSv2
  • Ocean initial conditions: JRA-55 forced ocean/sea-ice
  • Real-time forecasts since April 2021
  • 21-member ensemble for forecasts
  • Data availability on Climate Data Gateway & DOI: https://doi.org/10.5065/0s63-m767
  • Data availability on NCAR’s campaign storage (accessible from Casper)
    /glade/campaign/cesm/development/cross-wg/S2S/CESM2/S2SHINDCASTS/
  • Real-time data: Priority 1 variables are available from weekly real-time forecasts by Thursday am each week from a Globus endpoint:
    /glade/p/datashare/ssfcst/cesm2cam6v2/
    Visit the NCAR Data Sharing Service Page on instructions on how to access the data from the Globus endpoint

Subseasonal Reforecasts with CESM2(WACCM6)

  • Reforecasts initialized on Mondays between September and March between 1999 to 2020
  • 45-day simulations
  • 5-member ensemble for reforecasts
  • Atmospheric initial conditions: CESM2(WACCM6) specified dynamics run nudged to MERRA-2
  • Land initial conditions: CLM2 spun up with CFSv2
  • Ocean initial conditions: Hybrid: JRA-55 forced ocean/sea-ice every 5 yrs & MERRA-2 forced ocean in between
  • Real-time forecasts since September 2020
  • 21-member ensemble for forecasts
  • Data availability on Climate Data Gateway & DOI: https://doi.org/10.5065/ekns-e430
  • Data availability on NCAR’s campaign storage (accessible from Casper):
    /gpfs/csfs1/cesm/collections/S2Sfcst/POSTPROC/
  • Real-time data: Priority 1 variables and 3-D U, V, T, OMEGA are available from weekly real-time forecasts by Thursday am each week from a Globus endpoint:
    /glade/p/datashare/ssfcst/70Lwaccm6/
    Visit the NCAR Data Sharing Service Page on instructions on how to access the data from the Globus endpoint

Output from the simulations is extensive and includes SubX priority 1, 2, 3 variables, additional 6-hourly, and daily output of other 2-dimensional variables, and 3-dimensional output of selected fields. A complete output list can be found in Tables S1-S7 of the Supplement to Richter et al. (2021).

A full description of the two systems can be found in Richter et al. (2021), which has been recently revised. Please email jrichter@ucar.edu if you are interested in obtaining a pre-print.

Richter, J. H. , A. A. Glanville, J. Edwards, B. Kauffman, N. A. Davis, A. Jaye, N. M. Pedatella, L. Sun, J. Berner, W. M. Kim, S. G. Yeager, G. Danabasoglu, J. M. Caron, and K. W. Oleson (2021): “A subseasonal Earth system prediction framework with CESM2”, Journal of Advances in Modeling Earth Systems, Revised

Project Lead

Collaboration & Acknowledgement

We welcome collaborations! We would appreciate you letting us know that you’re using this dataset by emailing jrichter@ucar.edu to add your name to the Subseasonal-CESM2 Analysis registry.

When presenting results based on the above datasets in either oral or written form, please acknowledge the appropriate dataset DOIs (CESM2(CAM6): https://doi.org/10.5065/0s63-m767; CESM2(WACCM6): https://doi.org/10.5065/ekns-e430) as well as the Richter et al. (2021) dataset description.

Related Publications

Davis, N. A., Richter, J. H., Edwards, J., & Glanville, A. A. (2021). A positive zonal wind feedback on sudden stratospheric warming development revealed by CESM2 (WACCM6) reforecasts. Geophysical Research Letters, 48, e2020GL090863. https://doi.org/10.1029/2020GL090863

Pedatella, N. M., Richter, J. H., Edwards, J., & Glanville, A. A. (2021). Predictability of the mesosphere and lower thermosphere during major sudden stratospheric warmings. Geophysical Research Letters, 48, e2021GL093716. https://doi.org/10.1029/2021GL093716