Spatial patterns of lightning strikes in interior Alaska and their relations to elevation and vegetation

The relationship between lightning strike density, vegetation, and elevation was investigated at three different spatial scales: (i) interior Alaska (similar to630 000 km(2)), (ii) six longitudinal transects (similar to100 000 km(2)), and (iii) 17 individual physiographic subregions (similar to50 000 km(2)) within Alaska. The data consisted of 14 years (1986-1999) of observations by the Alaska Fire Service lightning strike detection network. The best explanation for the variation in lightning strike density was provided by a combination of the areal coverage of boreal forest and elevation. Each of these factors has the potential to influence the convective activity. Our study suggests that in a region that is climatically favorable for air-mass thunderstorms, surface proper-ties may enhance local lightning storm development in the boreal forest. Lightning strikes were found to occur frequently both in mountainous areas and at river flats, which is contrary to results from previous Alaskan studies.