Climate change

Delay due to oceanic heat capacity

Numerical experiment with an ocean-atmosphere coupled climate model in idealized condition [Spelman and Manabe, 1984]

Setting of experiments

Idealized geography, symmetric w.r.t equator. No seasonal cycle.


The result of C generally looks like approaching the state of B according to an exponential function of time (with a negative coefficient).

Result: Meridional (South-North) - vertical section of temperature difference

B (steady state exp.) - A (standard exp.)


Result: Meridional (South-North) - vertical section of temperature difference

C (25 years after CO2 quadrupling) - A (standard exp.)


The delay of global warming due to ocean heat capacity can be approximated by a linear model with a time constant corresponding to the heat capacity of the upper ocean (the part of ocean where wind-driven circulation dominates). The time series can be approximated by an exponential function tending to the new steady state.

A rough estimate of future temperature can be made by giving a realistic scenario of CO2 concentration to the linear model. (More detailed estimate will be done by giving such a CO2 concentration scenario to coupled 3-dimensional climate models.

[Text 2019-June-06] [Climate Change 2019]