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CSM Experiment Series b003

Introduction

Active Models: sea ice, ocean, atmosphere/land
Data Set Models: none

When run: August 1996 thru February 1997

Models used:

  • the NCAR CCM atmosphere model, CCM3.2
  • the NCAR Land Surface Model, version 1
  • the NCAR CSM Sea Ice Model, CSIM-3.5.3
  • the NCAR CSM (global) Ocean Model, NCOM-1.1
  • the NCAR CSM Flux Coupler, drv-3.a.2

    b003.01 Synopsis:
    This case improves upon and replaces case b001. Initial conditions were provided by the case g006 ocean & ice spinup run. It appears that this simulation will be very similar to case b001 in most respects, particularly within the atmosphere. Perhaps the most notable exception being significantly less drift in the ocean climate. We attribute this to a much improved ocean/ice spinup run (see case g006 ). Also, this case has an improved ice thickness and distribution which we attribute to improvements within the ice model code. The b003.01 integration was halted at the end of year 0060.

    b003.02 Synopsis:
    This case is a branch of the b003.01 integration, starting at year 0051. The only change from b003.01 is that atm/lnd and ice communications with the coupler are done at 1 hour (rather than 20 minute) intervals. The b003.01 integration was halted at the end of year 0099.

    b003.03 Synopsis:
    This case is a direct continuation of b003.02, albiet on a different computer with a different compiler. Essentially, cases b003.01 + b003.02 + b003.03 combine to form one coherent 300 year simulation. While there has been some drift in certain fields, deeper ocean temperatures for example, surface fields such as SST and ice extent have been remarkably stable, with any drift hidden in the noise level of climate variability. As a whole the simulation produced very reasonable results. The b003.03 integration was halted at year 0300.

    Some results:

  • From the b003.01 atmosphere model (frozen)
  • From the b003.01 sea-ice model (frozen)
  • From the b003.02 atmosphere model
  • From the b003.02 sea-ice model

    Accessing simulation output data:

  • From the b003.01 atmosphere model (years 00-50)
  • From the b003.02 atmosphere model (years 51-99)
  • From the b003.02 atmosphere model (years 100-299)

    Downloadable output data:

  • From the b003 atmosphere model (years 0000-0299)
  • From the b003 sea-ice model (years 0100-0299)

    Computer Resources:
    This simulation required about 114 CPU hours per simulated year on a Cray Y-MP with a 6 nano-second clock. The required memory was about 48 mega-words. On a dedicated 8 processor Y-MP, this coupled model used about 95% of the available CPU cycles. Considering a typical operating system overhead, this is effectively 100% machine utilization.

    Table of b003.nn runs:

    Date Case Description Start/End Owner
    b003 standard fully coupled run (replaces b001)