Lightning simulations at convection-permitting scale over the boreal zone

Recently, the boreal zone experienced more severe fire years, often coinciding with years of high lightning occurrence. Several studies indicate that lightning might further increase with global warming, threatening the huge carbon pools above (forests) and below the ground (peatlands) by possibly causing a wildfire regime shift. Current predictions are however highly uncertain, either relying on empirical relationships derived from present climate, or coarse-scale climate scenario simulations in which the critical process of deep convection is parameterized and the detailed representation of landatmosphere interactions is lacking. BOREALZEUS aims at providing a novel physically-based analysis of deep convection and lightning in the boreal zone by coupling convection-permitting high resolution atmospheric modeling to an advanced model of the typical boreal land surface mosaic. The hypothesis is that the two major boreal land cover types, forests and peatlands, play an important role in the initiation of deep convection and that the explicit simulation of the land-atmosphere interactions and deep convection will greatly improve the accuracy of lightning estimates with state-of-the-art lightning models. The new knowledge that is gained in BOREALZEUS is of critical importance to better predict the future impact of climate and land cover change on lightning and wildfire occurrence.