Abstract. Historical time series of surface temperature and ocean heat content changes
are commonly used metrics to diagnose climate change and estimate properties
of the climate system. We show that recent trends, namely the slowing of
surface temperature rise at the beginning of the 21st century and the
acceleration of heat stored in the deep ocean, have a substantial impact on
these estimates. Using the Massachusetts Institute of Technology Earth System
Model (MESM), we vary three model parameters that influence the behavior of
the climate system: effective climate sensitivity (ECS), the effective ocean
diffusivity of heat anomalies by all mixing processes (Kv), and the net
anthropogenic aerosol forcing scaling factor. Each model run is compared to
observed changes in decadal mean surface temperature anomalies and the trend
in global mean ocean heat content change to derive a joint probability
distribution function for the model parameters. Marginal distributions for
individual parameters are found by integrating over the other two parameters.
To investigate how the inclusion of recent temperature changes affects our
estimates, we systematically include additional data by choosing periods that
end in 1990, 2000, and 2010. We find that estimates of ECS increase in
response to rising global surface temperatures when data beyond 1990 are
included, but due to the slowdown of surface temperature rise in the early
21st century, estimates when using data up to 2000 are greater than when data
up to 2010 are used. We also show that estimates of Kv increase in
response to the acceleration of heat stored in the ocean as data beyond 1990
are included. Further, we highlight how including spatial patterns of surface
temperature change modifies the estimates. We show that including latitudinal
structure in the climate change signal impacts properties with spatial
dependence, namely the aerosol forcing pattern, more than properties defined
for the global mean, climate sensitivity, and ocean diffusivity.
Numerical simulation study of steel plate anti-penetrating features
