225
180 million years ago
parametrization
Pangea. (After Dietz and
Holden 1970)
of eating. Depending on the amount of toxin consumed, symptoms may
progress to tingling of fingers and toes, loss of control of arms and legs, followed by difficulty in breathing. Death can result (in approximately 15 % of
reported cases), due to paralysis of the breathing mechanisms in as little as
2 h. ~diarrheti( shellfish poisoning.
parametrization a method to reduce mathematical expressions describing a
complex process to simplified expressions that are easier to solve or more
open to experimental verification. Parameters formulating the effects of less
accessible elements of the process are introduced in a simplified equation.
The parameters have to be chosen in such a way that the solutions of the
reduced equations describe the process with sufficient accuracy. An example is the replacement of the Reynolds stress, consisting of the cross-product of
small-scale fluctuations, by the product of an eddy viscosity coefficient and a
gradient of the mean value.