An information-theoretic perspective on teleconnections

A classical paradigm for terrestrial climate variability involves remote sea surface temperature forcing, communicated to receptor regions via atmospheric teleconnections. Here the teleconnection link is abstracted in terms of Shannon's information-theoretic measure “channel capacity.” An upper bound on the channel capacity for December-January-February (DJF) seasonal precipitation teleconnections with sea surface temperature in the NINO3.4 region, when both variables are tercile-quantized, is estimated as 1 bit, meaning that it is only marginally possible to distinguish reliably between two NINO3.4 input states on the basis of observed precipitation output amounts, the central tercile acting principally to degrade reliability. A relationship between the channel capacity in a continuous model and the correlation coefficient is established; the corresponding nonlinear transformation provides a useful shift in perspective on the communication of information as such via teleconnections