Modelling space--time varying ENSO teleconnections to droughts in North America.

Teleconnection in atmospheric science refers to a significant correlation between climate anomalies in widely separated regions (typically thousands of kilometres), and it is often considered to be responsible for extreme weather conditions occurring simultaneously over large distances. In this paper, we study the influence of El Niño- Southern Oscillation teleconnection on meteorological droughts represented by the Palmer severity drought index across North America from 1870 to 1990. We develop a flexible statistical framework based on spatial random effects to model the covariance (teleconnection) between winter (October--March) sea surface temperature in the tropical Pacific and summer (June--August) droughts in North America. Our model allows us to analyse the dynamic pattern of teleconnection over space and time, and results indicate that the influence of El Niño-Southern Oscillation teleconnections on droughts varies spatially and temporally across North America. We further provide the timevarying teleconnection estimates with their uncertainties for 12 subregions in North America. [ABSTRACT FROM AUTHOR]