Modeling the effect of Greenland on wintertime cyclones and energy transport in the North Atlantic Gateway to the Arctic

This thesis investigates the role of the Greenland ice sheet and sea ice cover on synoptic development and poleward energy transports to the Arctic via the "North Atlantic Gateway". Simulations were conducted using a regional numerical weather prediction model (Polar MM5). Control simulations for individual cyclones and for month long runs were compared to sensitivity runs with the topography of; Greenland removed and with different sea ice conditions. Greenland encourages secondary cyclone formation through lee side effects and inhibits cyclone intensity by deflecting cyclones. Greenland discourages poleward (equatorward) sensible heat transports in positive (negative) months of the North Atlantic Oscillation (NAO). It also strongly inhibits latent heat transports during negative NAO months when the monthly mean 500 hPa flow is meridional at the tip of Greenland. Reduced (increased) sea ice concentration increases (decreases) surfaces fluxes and near surface temperatures. Cyclone tracks are not changed by changes in concentration.