| Summary: | Community Climate Model 3 (CCM3) is run on an idealized all land zonally
symmetric planet (Terra Blanda) with no seasonality, no snow and fixed soil moisture
to obtain a stationary time series effectively much longer than conventional runs with
geography and seasons. The surface temperature field generated is studied to analyze
the spatial and temporal spectra, estimate the length scale and time scale of the
model, and test the linearity of response to periodic and steady heat source forcings.
The length scale of the model is found to be in the range of 1000-2000 km and the time
scale is estimated to be 24 days for the global average surface temperature field. The
response of the global average temperature is found to be fairly linear to periodic and
the steady heat source forcings. The results obtained are compared with the results
of a similar study that used CCM0. Fluctuation Dissipation theorem is also tested
for applicability on CCM3. The response of the surface temperature field to a step
function forcing is demonstrated to be very similar to the decay of naturally occurring
anomalies, and the auto-correlation function. Return period of surface temperature
anomalies is also studied. It is observed that the length of the data obtained from
CCM3, though sufficient for analysis of first and second moments, is significantly
deficient for return period analysis. An AR1 process is simulated to model the global
averaged surface temperature of Terra Blanda 3 to assess the sampling error associated
with short runs.
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