Atmospheric transport and dispersion of the Mountain Pine Beetle in British Columbia, Canada

The Mountain Pine Beetle (MPB) outbreak in the central interior of British Columbia has reached epidemic proportions, affecting over 8 million hectares of forest. The emergence and flight of MPBs once they reach biological maturity, is determined by meteorological conditions - peak emergence and flight occurs when there is a sequence of three days with temperatures greater than 25 C that are characterized by the passage of an upper ridge, increased atmospheric instability and falling surface pressures. The rapid growth and expansion of the epidemic is likely due to long range transport of the insect, in which MPB are carried aloft by atmospheric instability and transported by the mean wind. This study discusses the use of an atmospheric mesoscale model (RAMS) to simulate over twenty emergence and flight events to determine how the atmosphere, over the complex terrain of central British Columbia, likely acts to transport the insect allowing it to dramatically expand its range.